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authorVito Caputo <vcaputo@gnugeneration.com>2017-01-18 17:14:52 -0800
committerVito Caputo <vcaputo@gnugeneration.com>2017-01-18 17:31:44 -0800
commit524db0cf19648e3c7c78d3e73103b7a0bdcd6bfc (patch)
tree6fd682629904a210927797c92d956c208666b03a /src
parentee2073d4e411555aba878277131b56f7eb562c84 (diff)
*: move source into src/ subdir
Restoring some organizational sanity since adopting autotools.
Diffstat (limited to 'src')
-rw-r--r--src/Makefile.am5
-rw-r--r--src/drmsetup.c162
-rw-r--r--src/drmsetup.h10
-rw-r--r--src/fb.c347
-rw-r--r--src/fb.h37
-rw-r--r--src/fps.c46
-rw-r--r--src/fps.h9
-rw-r--r--src/modules/Makefile.am1
-rw-r--r--src/modules/ray/Makefile.am4
-rw-r--r--src/modules/ray/ray.c161
-rw-r--r--src/modules/ray/ray.h8
-rw-r--r--src/modules/ray/ray_3f.h161
-rw-r--r--src/modules/ray/ray_camera.c85
-rw-r--r--src/modules/ray/ray_camera.h77
-rw-r--r--src/modules/ray/ray_color.h29
-rw-r--r--src/modules/ray/ray_euler.h45
-rw-r--r--src/modules/ray/ray_light_emitter.h18
-rw-r--r--src/modules/ray/ray_object.c74
-rw-r--r--src/modules/ray/ray_object.h24
-rw-r--r--src/modules/ray/ray_object_light.h67
-rw-r--r--src/modules/ray/ray_object_plane.h46
-rw-r--r--src/modules/ray/ray_object_point.h37
-rw-r--r--src/modules/ray/ray_object_sphere.h65
-rw-r--r--src/modules/ray/ray_object_type.h11
-rw-r--r--src/modules/ray/ray_ray.h11
-rw-r--r--src/modules/ray/ray_scene.c188
-rw-r--r--src/modules/ray/ray_scene.h27
-rw-r--r--src/modules/ray/ray_surface.h14
-rw-r--r--src/modules/ray/ray_threads.c111
-rw-r--r--src/modules/ray/ray_threads.h30
-rw-r--r--src/modules/roto/Makefile.am4
-rw-r--r--src/modules/roto/roto.c305
-rw-r--r--src/modules/roto/roto.h9
-rw-r--r--src/modules/sparkler/Makefile.am4
-rw-r--r--src/modules/sparkler/bsp.c584
-rw-r--r--src/modules/sparkler/bsp.h28
-rw-r--r--src/modules/sparkler/burst.c111
-rw-r--r--src/modules/sparkler/chunker.c225
-rw-r--r--src/modules/sparkler/chunker.h11
-rw-r--r--src/modules/sparkler/container.h11
-rw-r--r--src/modules/sparkler/draw.h32
-rw-r--r--src/modules/sparkler/list.h252
-rw-r--r--src/modules/sparkler/particle.c14
-rw-r--r--src/modules/sparkler/particle.h79
-rw-r--r--src/modules/sparkler/particles.c342
-rw-r--r--src/modules/sparkler/particles.h21
-rw-r--r--src/modules/sparkler/rocket.c144
-rw-r--r--src/modules/sparkler/simple.c113
-rw-r--r--src/modules/sparkler/spark.c63
-rw-r--r--src/modules/sparkler/sparkler.c53
-rw-r--r--src/modules/sparkler/sparkler.h8
-rw-r--r--src/modules/sparkler/v3f.h157
-rw-r--r--src/modules/sparkler/xplode.c82
-rw-r--r--src/modules/stars/Makefile.am4
-rw-r--r--src/modules/stars/draw.h32
-rw-r--r--src/modules/stars/stars.c63
-rw-r--r--src/modules/stars/stars.h8
-rw-r--r--src/modules/stars/starslib.c133
-rw-r--r--src/modules/stars/starslib.h19
-rw-r--r--src/rototiller.c87
-rw-r--r--src/rototiller.h12
-rw-r--r--src/util.c60
-rw-r--r--src/util.h28
63 files changed, 5008 insertions, 0 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..4203c02
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,5 @@
+SUBDIRS = modules
+bin_PROGRAMS = rototiller
+rototiller_SOURCES = drmsetup.c drmsetup.h fb.c fb.h fps.c fps.h rototiller.c rototiller.h util.c util.h
+rototiller_LDADD = @ROTOTILLER_LIBS@ -lm modules/ray/libray.a modules/roto/libroto.a modules/sparkler/libsparkler.a modules/stars/libstars.a
+rototiller_CPPFLAGS = @ROTOTILLER_CFLAGS@
diff --git a/src/drmsetup.c b/src/drmsetup.c
new file mode 100644
index 0000000..3670974
--- /dev/null
+++ b/src/drmsetup.c
@@ -0,0 +1,162 @@
+/*
+ * Rudimentary drm setup dialog... this is currently a very basic stdio thingy.
+ */
+
+#include <assert.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include "util.h"
+
+static const char * encoder_type_name(uint32_t type) {
+ static const char *encoder_types[] = {
+ "None",
+ "DAC",
+ "TMDS",
+ "LVDAC",
+ "VIRTUAL",
+ "DSI"
+ };
+
+ assert(type < nelems(encoder_types));
+
+ return encoder_types[type];
+}
+
+
+static const char * connector_type_name(uint32_t type) {
+ static const char *connector_types[] = {
+ "Unknown",
+ "VGA",
+ "DVII",
+ "DVID",
+ "DVIA",
+ "Composite",
+ "SVIDEO",
+ "LVDS",
+ "Component",
+ "SPinDIN",
+ "DisplayPort",
+ "HDMIA",
+ "HDMIB",
+ "TV",
+ "eDP",
+ "VIRTUAL",
+ "DSI"
+ };
+
+ assert(type < nelems(connector_types));
+
+ return connector_types[type];
+}
+
+
+static const char * connection_type_name(int type) {
+ static const char *connection_types[] = {
+ [1] = "Connected",
+ "Disconnected",
+ "Unknown"
+ };
+
+ assert(type < nelems(connection_types));
+
+ return connection_types[type];
+}
+
+
+/* interactively setup the drm device, store the selections */
+void drm_setup(int *res_drm_fd, uint32_t *res_crtc_id, uint32_t *res_connector_id, drmModeModeInfoPtr *res_mode)
+{
+ int drm_fd, i, connected;
+ drmVersionPtr drm_ver;
+ drmModeResPtr drm_res;
+ drmModeConnectorPtr drm_con;
+ drmModeEncoderPtr drm_enc;
+ drmModeCrtcPtr drm_crtc;
+ char dev[256];
+ int connector_num, mode_num;
+
+ pexit_if(!drmAvailable(),
+ "drm unavailable");
+
+ ask_string(dev, sizeof(dev), "DRM device", "/dev/dri/card0");
+
+ pexit_if((drm_fd = open(dev, O_RDWR)) < 0,
+ "unable to open drm device \"%s\"", dev);
+
+ pexit_if(!(drm_ver = drmGetVersion(drm_fd)),
+ "unable to get drm version");
+
+ printf("\nVersion: %i.%i.%i\nName: \"%.*s\"\nDate: \"%.*s\"\nDescription: \"%.*s\"\n\n",
+ drm_ver->version_major,
+ drm_ver->version_minor,
+ drm_ver->version_patchlevel,
+ drm_ver->name_len,
+ drm_ver->name,
+ drm_ver->date_len,
+ drm_ver->date,
+ drm_ver->desc_len,
+ drm_ver->desc);
+
+ pexit_if(!(drm_res = drmModeGetResources(drm_fd)),
+ "unable to get drm resources");
+
+ printf("\nConnectors\n");
+ connected = 0;
+ for (i = 0; i < drm_res->count_connectors; i++) {
+
+ pexit_if(!(drm_con = drmModeGetConnector(drm_fd, drm_res->connectors[i])),
+ "unable to get connector %x", (int)drm_res->connectors[i]);
+
+ if (!drm_con->encoder_id) {
+ continue;
+ }
+
+ pexit_if(!(drm_enc = drmModeGetEncoder(drm_fd, drm_con->encoder_id)),
+ "unable to get encoder %x", (int)drm_con->encoder_id);
+
+ connected++;
+
+ printf(" %i: %s (%s%s%s)\n",
+ i, connector_type_name(drm_con->connector_type),
+ connection_type_name(drm_con->connection),
+ drm_con->encoder_id ? " via " : "",
+ drm_con->encoder_id ? encoder_type_name(drm_enc->encoder_type) : "");
+ /* TODO show mmWidth/mmHeight? */
+ }
+
+ exit_if(!connected,
+ "No connectors available, try different card or my bug?");
+ ask_num(&connector_num, drm_res->count_connectors, "Select connector", 0); // TODO default?
+
+ pexit_if(!(drm_con = drmModeGetConnector(drm_fd, drm_res->connectors[connector_num])),
+ "unable to get connector %x", (int)drm_res->connectors[connector_num]);
+ pexit_if(!(drm_enc = drmModeGetEncoder(drm_fd, drm_con->encoder_id)),
+ "unable to get encoder %x", (int)drm_con->encoder_id);
+
+ pexit_if(!(drm_crtc = drmModeGetCrtc(drm_fd, drm_enc->crtc_id)),
+ "unable to get crtc %x", (int)drm_enc->crtc_id);
+
+ *res_drm_fd = drm_fd;
+ *res_crtc_id = drm_crtc->crtc_id;
+ *res_connector_id = drm_con->connector_id;
+
+ printf("\nModes\n");
+ for (i = 0; i < drm_con->count_modes; i++) {
+ printf(" %i: %s @ %"PRIu32"Hz\n",
+ i, drm_con->modes[i].name,
+ drm_con->modes[i].vrefresh);
+ }
+ ask_num(&mode_num, drm_con->count_modes, "Select mode", 0); // TODO default to &drm_crtc->mode?
+
+ *res_mode = &drm_con->modes[mode_num];
+}
diff --git a/src/drmsetup.h b/src/drmsetup.h
new file mode 100644
index 0000000..61af2d5
--- /dev/null
+++ b/src/drmsetup.h
@@ -0,0 +1,10 @@
+#ifndef _DRM_SETUP_H
+#define _DRM_SETUP_H
+
+#include <stddef.h> /* xf86drmMode.h uses size_t without including stddef.h, sigh */
+#include <stdint.h>
+#include <xf86drmMode.h>
+
+void drm_setup(int *res_drm_fd, uint32_t *res_crtc_id, uint32_t *res_connector_id, drmModeModeInfoPtr *res_mode);
+
+#endif
diff --git a/src/fb.c b/src/fb.c
new file mode 100644
index 0000000..4d1a562
--- /dev/null
+++ b/src/fb.c
@@ -0,0 +1,347 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include "fb.h"
+#include "util.h"
+
+/* Copyright (C) 2016 Vito Caputo <vcaputo@pengaru.com> */
+
+
+/* I've used a separate thread for page-flipping duties because the libdrm api
+ * (and related kernel ioctl) for page flips doesn't appear to support queueing
+ * multiple flip requests. In this use case we aren't interactive and wish to
+ * just accumulate rendered pages until we run out of spare pages, allowing the
+ * renderer to get as far ahead of vsync as possible, and certainly never
+ * blocked waiting for vsync unless there's no spare page available for drawing
+ * into.
+ *
+ * In lieu of a queueing mechanism on the drm fd, we must submit the next page
+ * once the currently submitted page is flipped to - it's at that moment we
+ * won't get EBUSY from the ioctl any longer. Without a dedicated thread
+ * submitting flip requests and synchronously consuming their flip events,
+ * we're liable to introduce latency in the page flip submission if implemented
+ * in a more opportunistic manner whenever the fb api is entered from the
+ * render loop.
+ *
+ * If the kernel simply let us queue multiple flip requests we could maintain
+ * our submission queue entirely in the drm fd, and get available pages from
+ * the drm event handler once our pool of pages is depleted. The kernel on
+ * vsync could check the fd to see if another flip is queued and there would be
+ * the least latency possible in submitting the flips - the least likely to
+ * miss a vsync. This would also elide the need for synchronization in
+ * userspace between the renderer and the flipper thread, since there would no
+ * longer be a flipper thread.
+ *
+ * Let me know if you're aware of a better way with existing mainline drm!
+ */
+
+
+/* Most of fb_page_t is kept private, the public part is
+ * just an fb_fragment_t describing the whole page.
+ */
+typedef struct _fb_page_t _fb_page_t;
+struct _fb_page_t {
+ _fb_page_t *next;
+ uint32_t *mmap;
+ size_t mmap_size;
+ uint32_t drm_dumb_handle;
+ uint32_t drm_fb_id;
+ fb_page_t public_page;
+};
+
+typedef struct fb_t {
+ pthread_t thread;
+ int drm_fd;
+ uint32_t drm_crtc_id;
+
+ _fb_page_t *active_page; /* page currently displayed */
+
+ pthread_mutex_t ready_mutex;
+ pthread_cond_t ready_cond;
+ _fb_page_t *ready_pages_head; /* next pages to flip to */
+ _fb_page_t *ready_pages_tail;
+
+ pthread_mutex_t inactive_mutex;
+ pthread_cond_t inactive_cond;
+ _fb_page_t *inactive_pages; /* finished pages available for (re)use */
+
+ unsigned put_pages_count;
+} fb_t;
+
+#ifndef container_of
+#define container_of(_ptr, _type, _member) \
+ (_type *)((void *)(_ptr) - offsetof(_type, _member))
+#endif
+
+
+/* Synchronize with the page flip by waiting for its event. */
+static inline void fb_drm_flip_wait(fb_t *fb)
+{
+ drmEventContext drm_ev_ctx = {
+ .version = DRM_EVENT_CONTEXT_VERSION,
+ .vblank_handler = NULL,
+ .page_flip_handler = NULL
+ };
+ drmHandleEvent(fb->drm_fd, &drm_ev_ctx);
+}
+
+
+/* Consumes ready pages queued via fb_page_put(), submits them to drm to flip
+ * on vsync. Produces inactive pages from those replaced, making them
+ * available to fb_page_get(). */
+static void * fb_flipper_thread(void *_fb)
+{
+ fb_t *fb = _fb;
+
+ for (;;) {
+ _fb_page_t *next_active_page;
+ /* wait for a flip req, submit the req page for flip on vsync, wait for it to flip before making the
+ * active page inactive/available, repeat.
+ */
+ pthread_mutex_lock(&fb->ready_mutex);
+ while (!fb->ready_pages_head)
+ pthread_cond_wait(&fb->ready_cond, &fb->ready_mutex);
+
+ next_active_page = fb->ready_pages_head;
+ fb->ready_pages_head = next_active_page->next;
+ if (!fb->ready_pages_head)
+ fb->ready_pages_tail = NULL;
+ pthread_mutex_unlock(&fb->ready_mutex);
+
+ /* submit the next active page for page flip on vsync, and wait for it. */
+ pexit_if(drmModePageFlip(fb->drm_fd, fb->drm_crtc_id, next_active_page->drm_fb_id, DRM_MODE_PAGE_FLIP_EVENT, NULL) < 0,
+ "unable to flip page");
+ fb_drm_flip_wait(fb);
+
+ /* now that we're displaying a new page, make the previously active one inactive so rendering can reuse it */
+ pthread_mutex_lock(&fb->inactive_mutex);
+ fb->active_page->next = fb->inactive_pages;
+ fb->inactive_pages = fb->active_page;
+ pthread_cond_signal(&fb->inactive_cond);
+ pthread_mutex_unlock(&fb->inactive_mutex);
+
+ fb->active_page = next_active_page;
+ }
+}
+
+
+/* creates a framebuffer page, which is a coupled drm_fb object and mmap region of memory */
+static void fb_page_new(fb_t *fb, drmModeModeInfoPtr mode)
+{
+ _fb_page_t *page;
+ struct drm_mode_create_dumb create_dumb = {
+ .width = mode->hdisplay,
+ .height = mode->vdisplay,
+ .bpp = 32,
+ .flags = 0, // unused,
+ };
+ struct drm_mode_map_dumb map_dumb = {
+ .pad = 0, // unused
+ };
+ uint32_t *map, fb_id;
+
+ page = calloc(1, sizeof(_fb_page_t));
+
+ pexit_if(ioctl(fb->drm_fd, DRM_IOCTL_MODE_CREATE_DUMB, &create_dumb) < 0,
+ "unable to create dumb buffer");
+
+ map_dumb.handle = create_dumb.handle;
+ pexit_if(ioctl(fb->drm_fd, DRM_IOCTL_MODE_MAP_DUMB, &map_dumb) < 0,
+ "unable to prepare dumb buffer for mmap");
+ pexit_if(!(map = mmap(NULL, create_dumb.size, PROT_READ|PROT_WRITE, MAP_SHARED, fb->drm_fd, map_dumb.offset)),
+ "unable to mmap dumb buffer");
+ pexit_if(drmModeAddFB(fb->drm_fd, mode->hdisplay, mode->vdisplay, 24, 32, create_dumb.pitch, create_dumb.handle, &fb_id) < 0,
+ "unable to add dumb buffer");
+
+ page->mmap = map;
+ page->mmap_size = create_dumb.size;
+ page->drm_dumb_handle = map_dumb.handle;
+ page->drm_fb_id = fb_id;
+
+ page->public_page.fragment.buf = map;
+ page->public_page.fragment.width = mode->hdisplay;
+ page->public_page.fragment.height = mode->vdisplay;
+ page->public_page.fragment.stride = create_dumb.pitch - (mode->hdisplay * 4);
+
+ page->next = fb->inactive_pages;
+ fb->inactive_pages = page;
+}
+
+
+static void _fb_page_free(fb_t *fb, _fb_page_t *page)
+{
+ struct drm_mode_destroy_dumb destroy_dumb = {
+ .handle = page->drm_dumb_handle,
+ };
+
+ drmModeRmFB(fb->drm_fd, page->drm_fb_id);
+ munmap(page->mmap, page->mmap_size);
+ ioctl(fb->drm_fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_dumb); // XXX: errors?
+ free(page);
+}
+
+
+/* get the next inactive page from the fb, waiting if necessary. */
+static inline _fb_page_t * _fb_page_get(fb_t *fb)
+{
+ _fb_page_t *page;
+
+ /* As long as n_pages is >= 3 this won't block unless we're submitting
+ * pages faster than vhz.
+ */
+ pthread_mutex_lock(&fb->inactive_mutex);
+ while (!(page = fb->inactive_pages))
+ pthread_cond_wait(&fb->inactive_cond, &fb->inactive_mutex);
+ fb->inactive_pages = page->next;
+ pthread_mutex_unlock(&fb->inactive_mutex);
+
+ page->next = NULL;
+
+ return page;
+}
+
+
+/* public interface */
+fb_page_t * fb_page_get(fb_t *fb)
+{
+ return &(_fb_page_get(fb)->public_page);
+}
+
+
+/* put a page into the fb, queueing for display */
+static inline void _fb_page_put(fb_t *fb, _fb_page_t *page)
+{
+ pthread_mutex_lock(&fb->ready_mutex);
+ if (fb->ready_pages_tail)
+ fb->ready_pages_tail->next = page;
+ else
+ fb->ready_pages_head = page;
+
+ fb->ready_pages_tail = page;
+ pthread_cond_signal(&fb->ready_cond);
+ pthread_mutex_unlock(&fb->ready_mutex);
+}
+
+
+/* public interface */
+
+/* put a page into the fb, queueing for display */
+void fb_page_put(fb_t *fb, fb_page_t *page)
+{
+ fb->put_pages_count++;
+
+ _fb_page_put(fb, container_of(page, _fb_page_t, public_page));
+}
+
+
+/* get (and reset) the current count of put pages */
+void fb_get_put_pages_count(fb_t *fb, unsigned *count)
+{
+ *count = fb->put_pages_count;
+ fb->put_pages_count = 0;
+}
+
+
+/* free the fb and associated resources */
+void fb_free(fb_t *fb)
+{
+ if (fb->active_page) {
+ pthread_cancel(fb->thread);
+ pthread_join(fb->thread, NULL);
+ }
+
+ /* TODO: free all the pages */
+
+ pthread_mutex_destroy(&fb->ready_mutex);
+ pthread_cond_destroy(&fb->ready_cond);
+ pthread_mutex_destroy(&fb->inactive_mutex);
+ pthread_cond_destroy(&fb->inactive_cond);
+
+ free(fb);
+}
+
+
+/* create a new fb instance */
+fb_t * fb_new(int drm_fd, uint32_t crtc_id, uint32_t *connectors, int n_connectors, drmModeModeInfoPtr mode, int n_pages)
+{
+ int i;
+ _fb_page_t *page;
+ fb_t *fb;
+
+ /* XXX: page-flipping is the only supported rendering model, requiring 2+ pages. */
+ if (n_pages < 2)
+ return NULL;
+
+ fb = calloc(1, sizeof(fb_t));
+ if (!fb)
+ return NULL;
+
+ fb->drm_fd = drm_fd;
+ fb->drm_crtc_id = crtc_id;
+
+ for (i = 0; i < n_pages; i++)
+ fb_page_new(fb, mode);
+
+ pthread_mutex_init(&fb->ready_mutex, NULL);
+ pthread_cond_init(&fb->ready_cond, NULL);
+ pthread_mutex_init(&fb->inactive_mutex, NULL);
+ pthread_cond_init(&fb->inactive_cond, NULL);
+
+ page = _fb_page_get(fb);
+
+ /* set the video mode, pinning this page, set it as the active page. */
+ if (drmModeSetCrtc(drm_fd, crtc_id, page->drm_fb_id, 0, 0, connectors, n_connectors, mode) < 0) {
+ _fb_page_free(fb, page);
+ fb_free(fb);
+ return NULL;
+ }
+
+ fb->active_page = page;
+
+ /* start up the page flipper thread */
+ pthread_create(&fb->thread, NULL, fb_flipper_thread, fb);
+
+ return fb;
+}
+
+
+/* divide a fragment into n_fragments, storing their values into fragments[],
+ * which is expected to have n_fragments of space. */
+void fb_fragment_divide(fb_fragment_t *fragment, unsigned n_fragments, fb_fragment_t fragments[])
+{
+ unsigned slice = fragment->height / n_fragments;
+ unsigned i;
+ void *buf = fragment->buf;
+ unsigned pitch = (fragment->width * 4) + fragment->stride;
+ unsigned y = fragment->y;
+
+ /* This just splits the supplied fragment into even horizontal slices */
+ /* TODO: It probably makes sense to add an fb_fragment_tile() as well, since some rendering
+ * algorithms benefit from the locality of a tiled fragment.
+ */
+
+ for (i = 0; i < n_fragments; i++) {
+ fragments[i].buf = buf;
+ fragments[i].x = fragment->x;
+ fragments[i].y = y;
+ fragments[i].width = fragment->width;
+ fragments[i].height = slice;
+ fragments[i].stride = fragment->stride;
+
+ buf += pitch * slice;
+ y += slice;
+ }
+ /* TODO: handle potential fractional tail slice? */
+}
diff --git a/src/fb.h b/src/fb.h
new file mode 100644
index 0000000..13f6bcd
--- /dev/null
+++ b/src/fb.h
@@ -0,0 +1,37 @@
+#ifndef _FB_H
+#define _FB_H
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <xf86drmMode.h> /* for drmModeModeInfoPtr */
+
+/* All renderers should target fb_fragment_t, which may or may not represent
+ * a full-screen mmap. Helpers are provided for subdividing fragments for
+ * concurrent renderers.
+ */
+typedef struct fb_fragment_t {
+ uint32_t *buf; /* pointer to the first pixel in the fragment */
+ unsigned x, y; /* absolute coordinates of the upper left corner of this fragment */
+ unsigned width, height; /* width and height of this fragment */
+ unsigned stride; /* number of bytes from the end of one row to the start of the next */
+} fb_fragment_t;
+
+/* This is a page handle object for page flip submission/life-cycle.
+ * Outside of fb_page_get()/fb_page_put(), you're going to be interested in
+ * fb_fragment_t. The fragment included here describes the whole page,
+ * it may be divided via fb_fragment_divide().
+ */
+typedef struct fb_page_t {
+ fb_fragment_t fragment;
+} fb_page_t;
+
+typedef struct fb_t fb_t;
+
+fb_page_t * fb_page_get(fb_t *fb);
+void fb_page_put(fb_t *fb, fb_page_t *page);
+void fb_free(fb_t *fb);
+void fb_get_put_pages_count(fb_t *fb, unsigned *count);
+fb_t * fb_new(int drm_fd, uint32_t crtc_id, uint32_t *connectors, int n_connectors, drmModeModeInfoPtr mode, int n_pages);
+void fb_fragment_divide(fb_fragment_t *fragment, unsigned n_fragments, fb_fragment_t fragments[]);
+
+#endif
diff --git a/src/fps.c b/src/fps.c
new file mode 100644
index 0000000..99a3f85
--- /dev/null
+++ b/src/fps.c
@@ -0,0 +1,46 @@
+#include <signal.h>
+#include <stdio.h>
+#include <sys/time.h>
+
+#include "fb.h"
+#include "util.h"
+
+
+static int print_fps;
+
+
+static void sigalrm_handler(int signum)
+{
+ print_fps = 1;
+}
+
+
+int fps_setup(void)
+{
+ struct itimerval interval = {
+ .it_interval = { .tv_sec = 1, .tv_usec = 0 },
+ .it_value = { .tv_sec = 1, .tv_usec = 0 },
+ };
+
+ if (signal(SIGALRM, sigalrm_handler) == SIG_ERR)
+ return 0;
+
+ if (setitimer(ITIMER_REAL, &interval, NULL) < 0)
+ return 0;
+
+ return 1;
+}
+
+
+void fps_print(fb_t *fb)
+{
+ unsigned n;
+
+ if (!print_fps)
+ return;
+
+ fb_get_put_pages_count(fb, &n);
+ printf("FPS: %u\n", n);
+
+ print_fps = 0;
+}
diff --git a/src/fps.h b/src/fps.h
new file mode 100644
index 0000000..1f986c7
--- /dev/null
+++ b/src/fps.h
@@ -0,0 +1,9 @@
+#ifndef _FPS_H
+#define _FPS_H
+
+#include "fb.h"
+
+int fps_setup(void);
+void fps_print(fb_t *fb);
+
+#endif
diff --git a/src/modules/Makefile.am b/src/modules/Makefile.am
new file mode 100644
index 0000000..a291174
--- /dev/null
+++ b/src/modules/Makefile.am
@@ -0,0 +1 @@
+SUBDIRS = ray roto sparkler stars
diff --git a/src/modules/ray/Makefile.am b/src/modules/ray/Makefile.am
new file mode 100644
index 0000000..a0b3fbb
--- /dev/null
+++ b/src/modules/ray/Makefile.am
@@ -0,0 +1,4 @@
+noinst_LIBRARIES = libray.a
+libray_a_SOURCES = ray_3f.h ray.c ray_camera.c ray_camera.h ray_color.h ray_euler.h ray.h ray_light_emitter.h ray_object.c ray_object.h ray_object_light.h ray_object_plane.h ray_object_point.h ray_object_sphere.h ray_object_type.h ray_ray.h ray_scene.c ray_scene.h ray_surface.h ray_threads.c ray_threads.h
+libray_a_CFLAGS = @ROTOTILLER_CFLAGS@ -ffast-math
+libray_a_CPPFLAGS = @ROTOTILLER_CFLAGS@ -I../../
diff --git a/src/modules/ray/ray.c b/src/modules/ray/ray.c
new file mode 100644
index 0000000..60d08cf
--- /dev/null
+++ b/src/modules/ray/ray.c
@@ -0,0 +1,161 @@
+#include <stdint.h>
+#include <inttypes.h>
+#include <math.h>
+
+#include "fb.h"
+#include "rototiller.h"
+#include "util.h"
+
+#include "ray_camera.h"
+#include "ray_object.h"
+#include "ray_scene.h"
+#include "ray_threads.h"
+
+/* Copyright (C) 2016 Vito Caputo <vcaputo@pengaru.com> */
+
+/* ray trace a simple scene into the fragment */
+static void ray(fb_fragment_t *fragment)
+{
+ static ray_object_t objects[] = {
+ {
+ .plane = {
+ .type = RAY_OBJECT_TYPE_PLANE,
+ .surface = {
+ .color = { .x = 0.4, .y = 0.2, .z = 0.5 },
+ .diffuse = 1.0f,
+ .specular = 0.2f,
+ },
+ .normal = { .x = 0.0, .y = 1.0, .z = 0.0 },
+ .distance = -3.2f,
+ }
+ }, {
+ .sphere = {
+ .type = RAY_OBJECT_TYPE_SPHERE,
+ .surface = {
+ .color = { .x = 1.0, .y = 0.0, .z = 0.0 },
+ .diffuse = 1.0f,
+ .specular = 0.05f,
+ },
+ .center = { .x = 0.5, .y = 1.0, .z = 0.0 },
+ .radius = 1.2f,
+ }
+ }, {
+ .sphere = {
+ .type = RAY_OBJECT_TYPE_SPHERE,
+ .surface = {
+ .color = { .x = 0.0, .y = 0.0, .z = 1.0 },
+ .diffuse = 1.0f,
+ .specular = 1.0f,
+ },
+ .center = { .x = -2.0, .y = 1.0, .z = 0.0 },
+ .radius = 0.9f,
+ }
+ }, {
+ .sphere = {
+ .type = RAY_OBJECT_TYPE_SPHERE,
+ .surface = {
+ .color = { .x = 0.0, .y = 1.0, .z = 1.0 },
+ .diffuse = 1.0f,
+ .specular = 1.0f,
+ },
+ .center = { .x = 2.0, .y = -1.0, .z = 0.0 },
+ .radius = 1.0f,
+ }
+ }, {
+ .sphere = {
+ .type = RAY_OBJECT_TYPE_SPHERE,
+ .surface = {
+ .color = { .x = 0.0, .y = 1.0, .z = 0.0 },
+ .diffuse = 1.0f,
+ .specular = 1.0f,
+ },
+ .center = { .x = 0.2, .y = -1.25, .z = 0.0 },
+ .radius = 0.6f,
+ }
+ }, {
+ .light = {
+ .type = RAY_OBJECT_TYPE_LIGHT,
+ .brightness = 1.0,
+ .emitter = {
+ .point.type = RAY_LIGHT_EMITTER_TYPE_POINT,
+ .point.center = { .x = 3.0f, .y = 3.0f, .z = 3.0f },
+ .point.surface = {
+ .color = { .x = 1.0f, .y = 1.0f, .z = 1.0f },
+ },
+ }
+ }
+ }
+ };
+
+ ray_camera_t camera = {
+ .position = { .x = 0.0, .y = 0.0, .z = 6.0 },
+ .orientation = {
+ .yaw = RAY_EULER_DEGREES(0.0f),
+ .pitch = RAY_EULER_DEGREES(0.0f),
+ .roll = RAY_EULER_DEGREES(180.0f),
+ },
+ .focal_length = 700.0f,
+ .width = fragment->width,
+ .height = fragment->height,
+ };
+
+ static ray_scene_t scene = {
+ .objects = objects,
+ .n_objects = nelems(objects),
+ .lights = &objects[5],
+ .n_lights = 1,
+ .ambient_color = { .x = 1.0f, .y = 1.0f, .z = 1.0f },
+ .ambient_brightness = .04f,
+ };
+ static int initialized;
+ static ray_threads_t *threads;
+ static fb_fragment_t *fragments;
+ static unsigned ncpus;
+#if 1
+ /* animated point light source */
+ static double r;
+
+ r += .02;
+
+ scene.lights[0].light.emitter.point.center.x = cosf(r) * 3.5f;
+ scene.lights[0].light.emitter.point.center.z = sinf(r) * 3.5f;
+ camera.orientation.yaw = sinf(r) / 4;
+ camera.orientation.pitch = sinf(r * 10) / 100;
+ camera.orientation.roll = RAY_EULER_DEGREES(180.0f) + cosf(r) / 10;
+ camera.position.x = cosf(r) / 10;
+ camera.position.z = 4.0f + sinf(r) / 10;
+#endif
+
+ if (!initialized) {
+ initialized = 1;
+ ncpus = get_ncpus();
+
+ if (ncpus > 1) {
+ threads = ray_threads_create(ncpus - 1);
+ fragments = malloc(sizeof(fb_fragment_t) * ncpus);
+ }
+ }
+
+ if (ncpus > 1) {
+ /* Always recompute the fragments[] geometry.
+ * This way the fragment geometry can change at any moment and things will
+ * continue functioning, which may prove important later on.
+ * (imagine things like a preview window, or perhaps composite modules
+ * which call on other modules supplying virtual fragments of varying dimensions..)
+ */
+ fb_fragment_divide(fragment, ncpus, fragments);
+ } else {
+ fragments = fragment;
+ }
+
+ ray_scene_render_fragments(&scene, &camera, threads, fragments);
+}
+
+
+rototiller_renderer_t ray_renderer = {
+ .render = ray,
+ .name = "ray",
+ .description = "Multi-threaded ray tracer",
+ .author = "Vito Caputo <vcaputo@pengaru.com>",
+ .license = "GPLv2",
+};
diff --git a/src/modules/ray/ray.h b/src/modules/ray/ray.h
new file mode 100644
index 0000000..d33f96a
--- /dev/null
+++ b/src/modules/ray/ray.h
@@ -0,0 +1,8 @@
+#ifndef _RAY_RAY_H
+#define _RAY_RAY_H
+
+#include "fb.h"
+
+void ray(fb_fragment_t *fragment);
+
+#endif
diff --git a/src/modules/ray/ray_3f.h b/src/modules/ray/ray_3f.h
new file mode 100644
index 0000000..8408abb
--- /dev/null
+++ b/src/modules/ray/ray_3f.h
@@ -0,0 +1,161 @@
+#ifndef _RAY_3F_H
+#define _RAY_3F_H
+
+#include <math.h>
+
+typedef struct ray_3f_t {
+ float x, y, z;
+} ray_3f_t;
+
+
+/* return the result of (a + b) */
+static inline ray_3f_t ray_3f_add(ray_3f_t *a, ray_3f_t *b)
+{
+ ray_3f_t res = {
+ .x = a->x + b->x,
+ .y = a->y + b->y,
+ .z = a->z + b->z,
+ };
+
+ return res;
+}
+
+
+/* return the result of (a - b) */
+static inline ray_3f_t ray_3f_sub(ray_3f_t *a, ray_3f_t *b)
+{
+ ray_3f_t res = {
+ .x = a->x - b->x,
+ .y = a->y - b->y,
+ .z = a->z - b->z,
+ };
+
+ return res;
+}
+
+
+/* return the result of (-v) */
+static inline ray_3f_t ray_3f_negate(ray_3f_t *v)
+{
+ ray_3f_t res = {
+ .x = -v->x,
+ .y = -v->y,
+ .z = -v->z,
+ };
+
+ return res;
+}
+
+
+/* return the result of (a * b) */
+static inline ray_3f_t ray_3f_mult(ray_3f_t *a, ray_3f_t *b)
+{
+ ray_3f_t res = {
+ .x = a->x * b->x,
+ .y = a->y * b->y,
+ .z = a->z * b->z,
+ };
+
+ return res;
+}
+
+
+/* return the result of (v * scalar) */
+static inline ray_3f_t ray_3f_mult_scalar(ray_3f_t *v, float scalar)
+{
+ ray_3f_t res = {
+ .x = v->x * scalar,
+ .y = v->y * scalar,
+ .z = v->z * scalar,
+ };
+
+ return res;
+}
+
+
+/* return the result of (uv / scalar) */
+static inline ray_3f_t ray_3f_div_scalar(ray_3f_t *v, float scalar)
+{
+ ray_3f_t res = {
+ .x = v->x / scalar,
+ .y = v->y / scalar,
+ .z = v->z / scalar,
+ };
+
+ return res;
+}
+
+
+/* return the result of (a . b) */
+static inline float ray_3f_dot(ray_3f_t *a, ray_3f_t *b)
+{
+ return a->x * b->x + a->y * b->y + a->z * b->z;
+}
+
+
+/* return the length of the supplied vector */
+static inline float ray_3f_length(ray_3f_t *v)
+{
+ return sqrtf(ray_3f_dot(v, v));
+}
+
+
+/* return the normalized form of the supplied vector */
+static inline ray_3f_t ray_3f_normalize(ray_3f_t *v)
+{
+ ray_3f_t nv;
+ float f;
+
+ f = 1.0f / ray_3f_length(v);
+
+ nv.x = f * v->x;
+ nv.y = f * v->y;
+ nv.z = f * v->z;
+
+ return nv;
+}
+
+
+/* return the distance between two arbitrary points */
+static inline float ray_3f_distance(ray_3f_t *a, ray_3f_t *b)
+{
+ return sqrtf(powf(a->x - b->x, 2) + powf(a->y - b->y, 2) + powf(a->z - b->z, 2));
+}
+
+
+/* return the cross product of two unit vectors */
+static inline ray_3f_t ray_3f_cross(ray_3f_t *a, ray_3f_t *b)
+{
+ ray_3f_t product;
+
+ product.x = a->y * b->z - a->z * b->y;
+ product.y = a->z * b->x - a->x * b->z;
+ product.z = a->x * b->y - a->y * b->x;
+
+ return product;
+}
+
+
+/* return the linearly interpolated vector between the two vectors at point alpha (0-1.0) */
+static inline ray_3f_t ray_3f_lerp(ray_3f_t *a, ray_3f_t *b, float alpha)
+{
+ ray_3f_t lerp_a, lerp_b;
+
+ lerp_a = ray_3f_mult_scalar(a, 1.0f - alpha);
+ lerp_b = ray_3f_mult_scalar(b, alpha);
+
+ return ray_3f_add(&lerp_a, &lerp_b);
+}
+
+
+/* return the normalized linearly interpolated vector between the two vectors at point alpha (0-1.0) */
+static inline ray_3f_t ray_3f_nlerp(ray_3f_t *a, ray_3f_t *b, float alpha)
+{
+ ray_3f_t lerp;
+
+ lerp = ray_3f_lerp(a, b, alpha);
+
+ return ray_3f_normalize(&lerp);
+}
+
+#endif
diff --git a/src/modules/ray/ray_camera.c b/src/modules/ray/ray_camera.c
new file mode 100644
index 0000000..0703c2e
--- /dev/null
+++ b/src/modules/ray/ray_camera.c
@@ -0,0 +1,85 @@
+#include "fb.h"
+
+#include "ray_camera.h"
+#include "ray_euler.h"
+
+
+/* Produce a vector from the provided orientation vectors and proportions. */
+static ray_3f_t project_corner(ray_3f_t *forward, ray_3f_t *left, ray_3f_t *up, float focal_length, float horiz, float vert)
+{
+ ray_3f_t tmp;
+ ray_3f_t corner;
+
+ corner = ray_3f_mult_scalar(forward, focal_length);
+ tmp = ray_3f_mult_scalar(left, horiz);
+ corner = ray_3f_add(&corner, &tmp);
+ tmp = ray_3f_mult_scalar(up, vert);
+ corner = ray_3f_add(&corner, &tmp);
+
+ return ray_3f_normalize(&corner);
+}
+
+
+/* Produce vectors for the corners of the entire camera frame, used for interpolation. */
+static void project_corners(ray_camera_t *camera, ray_camera_frame_t *frame)
+{
+ ray_3f_t forward, left, up, right, down;
+ float half_horiz = (float)camera->width / 2.0f;
+ float half_vert = (float)camera->height / 2.0f;
+
+ ray_euler_basis(&camera->orientation, &forward, &up, &left);
+ right = ray_3f_negate(&left);
+ down = ray_3f_negate(&up);
+
+ frame->nw = project_corner(&forward, &left, &up, camera->focal_length, half_horiz, half_vert);
+ frame->ne = project_corner(&forward, &right, &up, camera->focal_length, half_horiz, half_vert);
+ frame->se = project_corner(&forward, &right, &down, camera->focal_length, half_horiz, half_vert);
+ frame->sw = project_corner(&forward, &left, &down, camera->focal_length, half_horiz, half_vert);
+}
+
+
+/* Begin a frame for the fragment of camera projection, initializing frame and ray. */
+void ray_camera_frame_begin(ray_camera_t *camera, fb_fragment_t *fragment, ray_ray_t *ray, ray_camera_frame_t *frame)
+{
+ /* References are kept to the camera, fragment, and ray to be traced.
+ * The ray is maintained as we step through the frame, that is the
+ * purpose of this api.
+ *
+ * Since the ray direction should be a normalized vector, the obvious
+ * implementation is a bit costly. The camera frame api hides this
+ * detail so we can explore interpolation techniques to potentially
+ * lessen the per-pixel cost.
+ */
+ frame->camera = camera;
+ frame->fragment = fragment;
+ frame->ray = ray;
+
+ frame->x = frame->y = 0;
+
+ /* From camera->orientation and camera->focal_length compute the vectors
+ * through the viewport's corners, and place these normalized vectors
+ * in frame->(nw,ne,sw,se).
+ *
+ * These can than be interpolated between to produce the ray vectors
+ * throughout the frame's fragment. The efficient option of linear
+ * interpolation will not maintain the unit vector length, so to
+ * produce normalized interpolated directions will require the costly
+ * normalize function.
+ *
+ * I'm hoping a simple length correction table can be used to fixup the
+ * linearly interpolated vectors to make them unit vectors with just
+ * scalar multiplication instead of the sqrt of normalize.
+ */
+ project_corners(camera, frame);
+
+ frame->x_delta = 1.0f / (float)camera->width;
+ frame->y_delta = 1.0f / (float)camera->height;
+ frame->x_alpha = frame->x_delta * (float)fragment->x;
+ frame->y_alpha = frame->y_delta * (float)fragment->y;
+
+ frame->cur_w = ray_3f_nlerp(&frame->nw, &frame->sw, frame->y_alpha);
+ frame->cur_e = ray_3f_nlerp(&frame->ne, &frame->se, frame->y_alpha);
+
+ ray->origin = camera->position;
+ ray->direction = frame->cur_w;
+}
diff --git a/src/modules/ray/ray_camera.h b/src/modules/ray/ray_camera.h
new file mode 100644
index 0000000..387f8c5
--- /dev/null
+++ b/src/modules/ray/ray_camera.h
@@ -0,0 +1,77 @@
+#ifndef _RAY_CAMERA_H
+#define _RAY_CAMERA_H
+
+#include <math.h>
+
+#include "fb.h"
+
+#include "ray_3f.h"
+#include "ray_euler.h"
+#include "ray_ray.h"
+
+
+typedef struct ray_camera_t {
+ ray_3f_t position; /* position of camera, the origin of all its rays */
+ ray_euler_t orientation; /* orientation of the camera */
+ float focal_length; /* controls the field of view */
+ unsigned width; /* width of camera viewport in pixels */
+ unsigned height; /* height of camera viewport in pixels */
+} ray_camera_t;
+
+
+typedef struct ray_camera_frame_t {
+ ray_camera_t *camera; /* the camera supplied to frame_begin() */
+ fb_fragment_t *fragment; /* the fragment supplied to frame_begin() */
+ ray_ray_t *ray; /* the ray supplied to frame_begin(), which gets updated as we step through the frame. */
+
+ ray_3f_t nw, ne, sw, se; /* directions pointing through the corners of the frame fragment */
+ ray_3f_t cur_w, cur_e; /* current row's west and east ends */
+ float x_alpha, y_alpha; /* interpolation position along the x and y axis */
+ float x_delta, y_delta; /* interpolation step delta along the x and y axis */
+ unsigned x, y; /* integral position within frame fragment */
+} ray_camera_frame_t;
+
+
+void ray_camera_frame_begin(ray_camera_t *camera, fb_fragment_t *fragment, ray_ray_t *ray, ray_camera_frame_t *frame);
+
+
+/* Step the ray through the frame on the x axis, returns 1 when rays remain on this axis, 0 at the end. */
+/* When 1 is returned, frame->ray is left pointing through the new coordinate. */
+static inline int ray_camera_frame_x_step(ray_camera_frame_t *frame)
+{
+ frame->x++;
+
+ if (frame->x >= frame->fragment->width) {
+ frame->x = 0;
+ frame->x_alpha = frame->x_delta * (float)frame->fragment->x;
+ return 0;
+ }
+
+ frame->x_alpha += frame->x_delta;
+ frame->ray->direction = ray_3f_nlerp(&frame->cur_w, &frame->cur_e, frame->x_alpha);
+
+ return 1;
+}
+
+
+/* Step the ray through the frame on the y axis, returns 1 when rays remain on this axis, 0 at the end. */
+/* When 1 is returned, frame->ray is left pointing through the new coordinate. */
+static inline int ray_camera_frame_y_step(ray_camera_frame_t *frame)
+{
+ frame->y++;
+
+ if (frame->y >= frame->fragment->height) {
+ frame->y = 0;
+ frame->y_alpha = frame->y_delta * (float)frame->fragment->y;
+ return 0;
+ }
+
+ frame->y_alpha += frame->y_delta;
+ frame->cur_w = ray_3f_nlerp(&frame->nw, &frame->sw, frame->y_alpha);
+ frame->cur_e = ray_3f_nlerp(&frame->ne, &frame->se, frame->y_alpha);
+ frame->ray->direction = frame->cur_w;
+
+ return 1;
+}
+
+#endif
diff --git a/src/modules/ray/ray_color.h b/src/modules/ray/ray_color.h
new file mode 100644
index 0000000..9fe62c1
--- /dev/null
+++ b/src/modules/ray/ray_color.h
@@ -0,0 +1,29 @@
+#ifndef _RAY_COLOR_H
+#define _RAY_COLOR_H
+
+#include <stdint.h>
+
+#include "ray_3f.h"
+
+typedef ray_3f_t ray_color_t;
+
+/* convert a vector into a packed, 32-bit rgb pixel value */
+static inline uint32_t ray_color_to_uint32_rgb(ray_color_t color) {
+ uint32_t pixel;
+
+ /* doing this all per-pixel, ugh. */
+
+ if (color.x > 1.0f) color.x = 1.0f;
+ if (color.y > 1.0f) color.y = 1.0f;
+ if (color.z > 1.0f) color.z = 1.0f;
+
+ pixel = (uint32_t)(color.x * 255.0f);
+ pixel <<= 8;
+ pixel |= (uint32_t)(color.y * 255.0f);
+ pixel <<= 8;
+ pixel |= (uint32_t)(color.z * 255.0f);
+
+ return pixel;
+}
+
+#endif
diff --git a/src/modules/ray/ray_euler.h b/src/modules/ray/ray_euler.h
new file mode 100644
index 0000000..86f5221
--- /dev/null
+++ b/src/modules/ray/ray_euler.h
@@ -0,0 +1,45 @@
+#ifndef _RAY_EULER_H
+#define _RAY_EULER_H
+
+#include <math.h>
+
+#include "ray_3f.h"
+
+
+/* euler angles are convenient for describing orientation */
+typedef struct ray_euler_t {
+ float pitch; /* pitch in radiasn */
+ float yaw; /* yaw in radians */
+ float roll; /* roll in radians */
+} ray_euler_t;
+
+
+/* convenience macro for converting degrees to radians */
+#define RAY_EULER_DEGREES(_deg) \
+ (_deg * (2 * M_PI / 360.0f))
+
+
+/* produce basis vectors from euler angles */
+static inline void ray_euler_basis(ray_euler_t *e, ray_3f_t *forward, ray_3f_t *up, ray_3f_t *left)
+{
+ float cos_yaw = cosf(e->yaw);
+ float sin_yaw = sinf(e->yaw);
+ float cos_roll = cosf(e->roll);
+ float sin_roll = sinf(e->roll);
+ float cos_pitch = cosf(e->pitch);
+ float sin_pitch = sinf(e->pitch);
+
+ forward->x = sin_yaw;
+ forward->y = -sin_pitch * cos_yaw;
+ forward->z = cos_pitch * cos_yaw;
+
+ up->x = -cos_yaw * sin_roll;
+ up->y = -sin_pitch * sin_yaw * sin_roll + cos_pitch * cos_roll;
+ up->z = cos_pitch * sin_yaw * sin_roll + sin_pitch * cos_roll;
+
+ left->x = cos_yaw * cos_roll;
+ left->y = sin_pitch * sin_yaw * cos_roll + cos_pitch * sin_roll;
+ left->z = -cos_pitch * sin_yaw * cos_roll + sin_pitch * sin_roll;
+}
+
+#endif
diff --git a/src/modules/ray/ray_light_emitter.h b/src/modules/ray/ray_light_emitter.h
new file mode 100644
index 0000000..3b5509e
--- /dev/null
+++ b/src/modules/ray/ray_light_emitter.h
@@ -0,0 +1,18 @@
+#ifndef _RAY_LIGHT_EMITTER_H
+#define _RAY_LIGHT_EMITTER_H
+
+#include "ray_object_point.h"
+#include "ray_object_sphere.h"
+
+typedef enum ray_light_emitter_type_t {
+ RAY_LIGHT_EMITTER_TYPE_SPHERE,
+ RAY_LIGHT_EMITTER_TYPE_POINT,
+} ray_light_emitter_type_t;
+
+typedef union ray_light_emitter_t {
+ ray_light_emitter_type_t type;
+ ray_object_sphere_t sphere;
+ ray_object_point_t point;
+} ray_light_emitter_t;
+
+#endif
diff --git a/src/modules/ray/ray_object.c b/src/modules/ray/ray_object.c
new file mode 100644
index 0000000..4c5ccaf
--- /dev/null
+++ b/src/modules/ray/ray_object.c
@@ -0,0 +1,74 @@
+#include <assert.h>
+
+#include "ray_object.h"
+#include "ray_object_light.h"
+#include "ray_object_plane.h"
+#include "ray_object_point.h"
+#include "ray_object_sphere.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+/* Determine if a ray intersects object.
+ * If the object is intersected, store where along the ray the intersection occurs in res_distance.
+ */
+int ray_object_intersects_ray(ray_object_t *object, ray_ray_t *ray, float *res_distance)
+{
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ return ray_object_sphere_intersects_ray(&object->sphere, ray, res_distance);
+
+ case RAY_OBJECT_TYPE_POINT:
+ return ray_object_point_intersects_ray(&object->point, ray, res_distance);
+
+ case RAY_OBJECT_TYPE_PLANE:
+ return ray_object_plane_intersects_ray(&object->plane, ray, res_distance);
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ return ray_object_light_intersects_ray(&object->light, ray, res_distance);
+ default:
+ assert(0);
+ }
+}
+
+
+/* Return the surface normal of object @ point */
+ray_3f_t ray_object_normal(ray_object_t *object, ray_3f_t *point)
+{
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ return ray_object_sphere_normal(&object->sphere, point);
+
+ case RAY_OBJECT_TYPE_POINT:
+ return ray_object_point_normal(&object->point, point);
+
+ case RAY_OBJECT_TYPE_PLANE:
+ return ray_object_plane_normal(&object->plane, point);
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ return ray_object_light_normal(&object->light, point);
+ default:
+ assert(0);
+ }
+}
+
+
+/* Return the surface of object @ point */
+ray_surface_t ray_object_surface(ray_object_t *object, ray_3f_t *point)
+{
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ return ray_object_sphere_surface(&object->sphere, point);
+
+ case RAY_OBJECT_TYPE_POINT:
+ return ray_object_point_surface(&object->point, point);
+
+ case RAY_OBJECT_TYPE_PLANE:
+ return ray_object_plane_surface(&object->plane, point);
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ return ray_object_light_surface(&object->light, point);
+ default:
+ assert(0);
+ }
+}
diff --git a/src/modules/ray/ray_object.h b/src/modules/ray/ray_object.h
new file mode 100644
index 0000000..abdb254
--- /dev/null
+++ b/src/modules/ray/ray_object.h
@@ -0,0 +1,24 @@
+#ifndef _RAY_OBJECT_H
+#define _RAY_OBJECT_H
+
+#include "ray_object_light.h"
+#include "ray_object_plane.h"
+#include "ray_object_point.h"
+#include "ray_object_sphere.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+typedef union ray_object_t {
+ ray_object_type_t type;
+ ray_object_sphere_t sphere;
+ ray_object_point_t point;
+ ray_object_plane_t plane;
+ ray_object_light_t light;
+} ray_object_t;
+
+int ray_object_intersects_ray(ray_object_t *object, ray_ray_t *ray, float *res_distance);
+ray_3f_t ray_object_normal(ray_object_t *object, ray_3f_t *point);
+ray_surface_t ray_object_surface(ray_object_t *object, ray_3f_t *point);
+
+#endif
diff --git a/src/modules/ray/ray_object_light.h b/src/modules/ray/ray_object_light.h
new file mode 100644
index 0000000..342c050
--- /dev/null
+++ b/src/modules/ray/ray_object_light.h
@@ -0,0 +1,67 @@
+#ifndef _RAY_OBJECT_LIGHT_H
+#define _RAY_OBJECT_LIGHT_H
+
+#include <assert.h>
+
+#include "ray_light_emitter.h"
+#include "ray_object_light.h"
+#include "ray_object_point.h"
+#include "ray_object_sphere.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_object_light_t {
+ ray_object_type_t type;
+ float brightness;
+ ray_light_emitter_t emitter;
+} ray_object_light_t;
+
+
+/* TODO: point is really the only one I've implemented... */
+static inline int ray_object_light_intersects_ray(ray_object_light_t *light, ray_ray_t *ray, float *res_distance)
+{
+ switch (light->emitter.type) {
+ case RAY_LIGHT_EMITTER_TYPE_POINT:
+ return ray_object_point_intersects_ray(&light->emitter.point, ray, res_distance);
+
+ case RAY_LIGHT_EMITTER_TYPE_SPHERE:
+ return ray_object_sphere_intersects_ray(&light->emitter.sphere, ray, res_distance);
+ default:
+ assert(0);
+ }
+}
+
+
+static inline ray_3f_t ray_object_light_normal(ray_object_light_t *light, ray_3f_t *point)
+{
+ ray_3f_t normal;
+
+ /* TODO */
+ switch (light->emitter.type) {
+ case RAY_LIGHT_EMITTER_TYPE_SPHERE:
+ return normal;
+
+ case RAY_LIGHT_EMITTER_TYPE_POINT:
+ return normal;
+ default:
+ assert(0);
+ }
+}
+
+
+static inline ray_surface_t ray_object_light_surface(ray_object_light_t *light, ray_3f_t *point)
+{
+ switch (light->emitter.type) {
+ case RAY_LIGHT_EMITTER_TYPE_SPHERE:
+ return ray_object_sphere_surface(&light->emitter.sphere, point);
+
+ case RAY_LIGHT_EMITTER_TYPE_POINT:
+ return ray_object_point_surface(&light->emitter.point, point);
+ default:
+ assert(0);
+ }
+}
+
+#endif
diff --git a/src/modules/ray/ray_object_plane.h b/src/modules/ray/ray_object_plane.h
new file mode 100644
index 0000000..b33f342
--- /dev/null
+++ b/src/modules/ray/ray_object_plane.h
@@ -0,0 +1,46 @@
+#ifndef _RAY_OBJECT_PLANE_H
+#define _RAY_OBJECT_PLANE_H
+
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_object_plane_t {
+ ray_object_type_t type;
+ ray_surface_t surface;
+ ray_3f_t normal;
+ float distance;
+} ray_object_plane_t;
+
+
+static inline int ray_object_plane_intersects_ray(ray_object_plane_t *plane, ray_ray_t *ray, float *res_distance)
+{
+ float d = ray_3f_dot(&plane->normal, &ray->direction);
+
+ if (d != 0) {
+ float distance = -(ray_3f_dot(&plane->normal, &ray->origin) + plane->distance) / d;
+
+ if (distance > 0) {
+ *res_distance = distance;
+
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
+static inline ray_3f_t ray_object_plane_normal(ray_object_plane_t *plane, ray_3f_t *point)
+{
+ return plane->normal;
+}
+
+
+static inline ray_surface_t ray_object_plane_surface(ray_object_plane_t *plane, ray_3f_t *point)
+{
+ return plane->surface;
+}
+
+#endif
diff --git a/src/modules/ray/ray_object_point.h b/src/modules/ray/ray_object_point.h
new file mode 100644
index 0000000..c0c9610
--- /dev/null
+++ b/src/modules/ray/ray_object_point.h
@@ -0,0 +1,37 @@
+#ifndef _RAY_OBJECT_POINT_H
+#define _RAY_OBJECT_POINT_H
+
+#include "ray_3f.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_object_point_t {
+ ray_object_type_t type;
+ ray_surface_t surface;
+ ray_3f_t center;
+} ray_object_point_t;
+
+
+static inline int ray_object_point_intersects_ray(ray_object_point_t *point, ray_ray_t *ray, float *res_distance)
+{
+ /* TODO: determine a ray:point intersection */
+ return 0;
+}
+
+
+static inline ray_3f_t ray_object_point_normal(ray_object_point_t *point, ray_3f_t *_point)
+{
+ ray_3f_t normal;
+
+ return normal;
+}
+
+
+static inline ray_surface_t ray_object_point_surface(ray_object_point_t *point, ray_3f_t *_point)
+{
+ return point->surface;
+}
+
+#endif
diff --git a/src/modules/ray/ray_object_sphere.h b/src/modules/ray/ray_object_sphere.h
new file mode 100644
index 0000000..85b3d93
--- /dev/null
+++ b/src/modules/ray/ray_object_sphere.h
@@ -0,0 +1,65 @@
+#ifndef _RAY_OBJECT_SPHERE_H
+#define _RAY_OBJECT_SPHERE_H
+
+#include <math.h>
+#include <stdio.h>
+
+#include "ray_3f.h"
+#include "ray_color.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_object_sphere_t {
+ ray_object_type_t type;
+ ray_surface_t surface;
+ ray_3f_t center;
+ float radius;
+} ray_object_sphere_t;
+
+
+static inline int ray_object_sphere_intersects_ray(ray_object_sphere_t *sphere, ray_ray_t *ray, float *res_distance)
+{
+ ray_3f_t v = ray_3f_sub(&ray->origin, &sphere->center);
+ float b = ray_3f_dot(&v, &ray->direction);
+ float disc = (sphere->radius * sphere->radius) - ray_3f_dot(&v, &v) + (b * b);
+
+ if (disc > 0) {
+ float i1, i2;
+
+ disc = sqrtf(disc);
+
+ i1 = b - disc;
+ i2 = b + disc;
+
+ if (i2 > 0 && i1 > 0) {
+ *res_distance = i1;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
+/* return the normal of the surface at the specified point */
+static inline ray_3f_t ray_object_sphere_normal(ray_object_sphere_t *sphere, ray_3f_t *point)
+{
+ ray_3f_t normal;
+
+ normal = ray_3f_sub(point, &sphere->center);
+ normal = ray_3f_div_scalar(&normal, sphere->radius); /* normalize without the sqrt() */
+
+ return normal;
+}
+
+
+/* return the surface of the sphere @ point */
+static inline ray_surface_t ray_object_sphere_surface(ray_object_sphere_t *sphere, ray_3f_t *point)
+{
+ /* uniform solids for now... */
+ return sphere->surface;
+}
+
+#endif
diff --git a/src/modules/ray/ray_object_type.h b/src/modules/ray/ray_object_type.h
new file mode 100644
index 0000000..6ce20f5
--- /dev/null
+++ b/src/modules/ray/ray_object_type.h
@@ -0,0 +1,11 @@
+#ifndef _RAY_OBJECT_TYPE_H
+#define _RAY_OBJECT_TYPE_H
+
+typedef enum ray_object_type_t {
+ RAY_OBJECT_TYPE_SPHERE,
+ RAY_OBJECT_TYPE_POINT,
+ RAY_OBJECT_TYPE_PLANE,
+ RAY_OBJECT_TYPE_LIGHT,
+} ray_object_type_t;
+
+#endif
diff --git a/src/modules/ray/ray_ray.h b/src/modules/ray/ray_ray.h
new file mode 100644
index 0000000..91469a2
--- /dev/null
+++ b/src/modules/ray/ray_ray.h
@@ -0,0 +1,11 @@
+#ifndef _RAY_RAY_H
+#define _RAY_RAY_H
+
+#include "ray_3f.h"
+
+typedef struct ray_ray_t {
+ ray_3f_t origin;
+ ray_3f_t direction;
+} ray_ray_t;
+
+#endif
diff --git a/src/modules/ray/ray_scene.c b/src/modules/ray/ray_scene.c
new file mode 100644
index 0000000..e44990b
--- /dev/null
+++ b/src/modules/ray/ray_scene.c
@@ -0,0 +1,188 @@
+#include <stdlib.h>
+#include <math.h>
+
+#include "fb.h"
+
+#include "ray_camera.h"
+#include "ray_color.h"
+#include "ray_object.h"
+#include "ray_ray.h"
+#include "ray_scene.h"
+#include "ray_threads.h"
+
+#define MAX_RECURSION_DEPTH 5
+
+
+static ray_color_t trace_ray(ray_scene_t *scene, ray_ray_t *ray, unsigned depth);
+
+
+/* Determine if the ray is obstructed by an object within the supplied distance, for shadows */
+static inline int ray_is_obstructed(ray_scene_t *scene, ray_ray_t *ray, float distance)
+{
+ unsigned i;
+
+ for (i = 0; i < scene->n_objects; i++) {
+ float ood;
+
+ if (scene->objects[i].type == RAY_OBJECT_TYPE_LIGHT)
+ continue;
+
+ if (ray_object_intersects_ray(&scene->objects[i], ray, &ood) &&
+ ood < distance) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
+/* Determine the color @ distance on ray on object viewed from origin */
+static inline ray_color_t shade_ray(ray_scene_t *scene, ray_ray_t *ray, ray_object_t *object, float distance, unsigned depth)
+{
+ ray_surface_t surface;
+ ray_color_t color;
+ ray_3f_t rvec = ray_3f_mult_scalar(&ray->direction, distance);
+ ray_3f_t intersection = ray_3f_sub(&ray->origin, &rvec);
+ ray_3f_t normal = ray_object_normal(object, &intersection);
+ unsigned i;
+
+ surface = ray_object_surface(object, &intersection);
+ color = ray_3f_mult_scalar(&scene->ambient_color, scene->ambient_brightness);
+ color = ray_3f_mult(&surface.color, &color);
+
+ /* visit lights for shadows and illumination */
+ for (i = 0; i < scene->n_lights; i++) {
+ ray_3f_t lvec = ray_3f_sub(&scene->lights[i].light.emitter.point.center, &intersection);
+ float ldist = ray_3f_length(&lvec);
+ float lvec_normal_dot;
+ ray_ray_t shadow_ray;
+
+ lvec = ray_3f_mult_scalar(&lvec, (1.0f / ldist)); /* normalize lvec */
+#if 1
+ /* skip this light if it's obstructed,
+ * we must shift the origin slightly towards the light to prevent
+ * spurious self-obstruction at the ray:object intersection */
+ /* negate the light vector so it's pointed at the light rather than from it */
+ shadow_ray.direction = ray_3f_negate(&lvec);
+ shadow_ray.origin = ray_3f_mult_scalar(&shadow_ray.direction, 0.00001f);
+ shadow_ray.origin = ray_3f_add(&shadow_ray.origin, &intersection);
+
+ if (ray_is_obstructed(scene, &shadow_ray, ldist))
+ continue;
+#endif
+ lvec_normal_dot = ray_3f_dot(&normal, &lvec);
+
+ if (lvec_normal_dot > 0) {
+#if 1
+ float rvec_lvec_dot = ray_3f_dot(&ray->direction, &lvec);
+ ray_color_t diffuse;
+ ray_color_t specular;
+
+ diffuse = ray_3f_mult_scalar(&surface.color, lvec_normal_dot);
+ diffuse = ray_3f_mult_scalar(&diffuse, surface.diffuse);
+ color = ray_3f_add(&color, &diffuse);
+
+ /* FIXME: assumes light is a point for its color, and 20 is a constant "Phong exponent",
+ * which should really be object/surface-specific
+ */
+ specular = ray_3f_mult_scalar(&scene->lights[i].light.emitter.point.surface.color, powf(rvec_lvec_dot, 20));
+ specular = ray_3f_mult_scalar(&specular, surface.specular);
+ color = ray_3f_add(&color, &specular);
+#else
+ ray_color_t diffuse;
+
+ diffuse = ray_3f_mult_scalar(&surface.color, lvec_normal_dot);
+ color = ray_3f_add(&color, &diffuse);
+#endif
+ }
+ }
+
+ /* generate a reflection ray */
+#if 1
+ float dot = ray_3f_dot(&ray->direction, &normal);
+ ray_ray_t reflected_ray = { .direction = ray_3f_mult_scalar(&normal, dot * 2.0f) };
+ ray_3f_t reflection;
+
+ reflected_ray.origin = intersection;
+ reflected_ray.direction = ray_3f_sub(&ray->direction, &reflected_ray.direction);
+
+ reflection = trace_ray(scene, &reflected_ray, depth + 1);
+ reflection = ray_3f_mult_scalar(&reflection, surface.specular);
+ color = ray_3f_add(&color, &reflection);
+#endif
+
+ /* TODO: generate a refraction ray */
+
+ return color;
+}
+
+
+static ray_color_t trace_ray(ray_scene_t *scene, ray_ray_t *ray, unsigned depth)
+{
+ ray_object_t *nearest_object = NULL;
+ float nearest_object_distance = INFINITY;
+ ray_color_t color = { .x = 0.0, .y = 0.0, .z = 0.0 };
+ unsigned i;
+
+ depth++;
+ if (depth > MAX_RECURSION_DEPTH)
+ return color;
+
+ for (i = 0; i < scene->n_objects; i++) {
+ float distance;
+
+ /* Does this ray intersect object? */
+ if (ray_object_intersects_ray(&scene->objects[i], ray, &distance)) {
+
+ /* Is it the nearest intersection? */
+ if (!nearest_object ||
+ distance < nearest_object_distance) {
+ nearest_object = &scene->objects[i];
+ nearest_object_distance = distance;
+ }
+ }
+ }
+
+ if (nearest_object)
+ color = shade_ray(scene, ray, nearest_object, nearest_object_distance, depth);
+
+ depth--;
+
+ return color;
+}
+
+
+void ray_scene_render_fragment(ray_scene_t *scene, ray_camera_t *camera, fb_fragment_t *fragment)
+{
+ ray_camera_frame_t frame;
+ ray_ray_t ray;
+ uint32_t *buf = fragment->buf;
+ unsigned stride = fragment->stride / 4;
+
+ ray_camera_frame_begin(camera, fragment, &ray, &frame);
+ do {
+ do {
+ *buf = ray_color_to_uint32_rgb(trace_ray(scene, &ray, 0));
+ buf++;
+ } while (ray_camera_frame_x_step(&frame));
+
+ buf += stride;
+ } while (ray_camera_frame_y_step(&frame));
+}
+
+/* we expect fragments[threads->n_threads + 1], or fragments[1] when threads == NULL */
+void ray_scene_render_fragments(ray_scene_t *scene, ray_camera_t *camera, ray_threads_t *threads, fb_fragment_t *fragments)
+{
+ unsigned n_threads = threads ? threads->n_threads + 1 : 1;
+ unsigned i;
+
+ for (i = 1; i < n_threads; i++)
+ ray_thread_fragment_submit(&threads->threads[i - 1], scene, camera, &fragments[i]);
+
+ /* always render the zero fragment in-line */
+ ray_scene_render_fragment(scene, camera, &fragments[0]);
+
+ for (i = 1; i < n_threads; i++)
+ ray_thread_wait_idle(&threads->threads[i - 1]);
+}
diff --git a/src/modules/ray/ray_scene.h b/src/modules/ray/ray_scene.h
new file mode 100644
index 0000000..e9781c6
--- /dev/null
+++ b/src/modules/ray/ray_scene.h
@@ -0,0 +1,27 @@
+#ifndef _RAY_SCENE_H
+#define _RAY_SCENE_H
+
+#include "fb.h"
+
+#include "ray_camera.h"
+#include "ray_color.h"
+#include "ray_ray.h"
+#include "ray_threads.h"
+
+typedef union ray_object_t ray_object_t;
+
+typedef struct ray_scene_t {
+ ray_object_t *objects;
+ unsigned n_objects;
+
+ ray_object_t *lights;
+ unsigned n_lights;
+
+ ray_color_t ambient_color;
+ float ambient_brightness;
+} ray_scene_t;
+
+void ray_scene_render_fragments(ray_scene_t *scene, ray_camera_t *camera, ray_threads_t *threads, fb_fragment_t *fragments);
+void ray_scene_render_fragment(ray_scene_t *scene, ray_camera_t *camera, fb_fragment_t *fragment);
+
+#endif
diff --git a/src/modules/ray/ray_surface.h b/src/modules/ray/ray_surface.h
new file mode 100644
index 0000000..b3e3c68
--- /dev/null
+++ b/src/modules/ray/ray_surface.h
@@ -0,0 +1,14 @@
+#ifndef _RAY_MATERIAL_H
+#define _RAY_MATERIAL_H
+
+#include "ray_3f.h"
+#include "ray_color.h"
+
+/* Surface properties we expect every object to be able to introspect */
+typedef struct ray_surface_t {
+ ray_color_t color;
+ float specular;
+ float diffuse;
+} ray_surface_t;
+
+#endif
diff --git a/src/modules/ray/ray_threads.c b/src/modules/ray/ray_threads.c
new file mode 100644
index 0000000..2369687
--- /dev/null
+++ b/src/modules/ray/ray_threads.c
@@ -0,0 +1,111 @@
+#include <pthread.h>
+#include <stdlib.h>
+
+#include "fb.h"
+
+#include "ray_scene.h"
+#include "ray_threads.h"
+
+#define BUSY_WAIT_NUM 1000000000 /* How much to spin before sleeping in pthread_cond_wait() */
+
+/* for now assuming x86 */
+#define cpu_relax() \
+ __asm__ __volatile__ ( "pause\n" : : : "memory")
+
+/* This is a very simple/naive implementation, there's certainly room for improvement.
+ *
+ * Without the BUSY_WAIT_NUM spinning this approach seems to leave a fairly
+ * substantial proportion of CPU idle while waiting for the render thread to
+ * complete on my core 2 duo.
+ *
+ * It's probably just latency in getting the render thread woken when the work
+ * is submitted, and since the fragments are split equally the main thread gets
+ * a head start and has to wait when it finishes first. The spinning is just
+ * an attempt to avoid going to sleep while the render threads finish, there
+ * still needs to be improvement in how the work is submitted.
+ *
+ * I haven't spent much time on optimizing the raytracer yet.
+ */
+
+static void * ray_thread_func(void *_thread)
+{
+ ray_thread_t *thread = _thread;
+
+ for (;;) {
+ pthread_mutex_lock(&thread->mutex);
+ while (thread->fragment == NULL)
+ pthread_cond_wait(&thread->cond, &thread->mutex);
+
+ ray_scene_render_fragment(thread->scene, thread->camera, thread->fragment);
+ thread->fragment = NULL;
+ pthread_mutex_unlock(&thread->mutex);
+ pthread_cond_signal(&thread->cond);
+ }
+
+ return NULL;
+}
+
+
+void ray_thread_fragment_submit(ray_thread_t *thread, ray_scene_t *scene, ray_camera_t *camera, fb_fragment_t *fragment)
+{
+ pthread_mutex_lock(&thread->mutex);
+ while (thread->fragment != NULL) /* XXX: never true due to ray_thread_wait_idle() */
+ pthread_cond_wait(&thread->cond, &thread->mutex);
+
+ thread->fragment = fragment;
+ thread->scene = scene;
+ thread->camera = camera;
+
+ pthread_mutex_unlock(&thread->mutex);
+ pthread_cond_signal(&thread->cond);
+}
+
+
+void ray_thread_wait_idle(ray_thread_t *thread)
+{
+ unsigned n;
+
+ /* Spin before going to sleep, the other thread should not take substantially longer. */
+ for (n = 0; thread->fragment != NULL && n < BUSY_WAIT_NUM; n++)
+ cpu_relax();
+
+ pthread_mutex_lock(&thread->mutex);
+ while (thread->fragment != NULL)
+ pthread_cond_wait(&thread->cond, &thread->mutex);
+ pthread_mutex_unlock(&thread->mutex);
+}
+
+
+ray_threads_t * ray_threads_create(unsigned num)
+{
+ ray_threads_t *threads;
+ unsigned i;
+
+ threads = malloc(sizeof(ray_threads_t) + sizeof(ray_thread_t) * num);
+ if (!threads)
+ return NULL;
+
+ for (i = 0; i < num; i++) {
+ pthread_mutex_init(&threads->threads[i].mutex, NULL);
+ pthread_cond_init(&threads->threads[i].cond, NULL);
+ threads->threads[i].fragment = NULL;
+ pthread_create(&threads->threads[i].thread, NULL, ray_thread_func, &threads->threads[i]);
+ }
+ threads->n_threads = num;
+
+ return threads;
+}
+
+
+void ray_threads_destroy(ray_threads_t *threads)
+{
+ unsigned i;
+
+ for (i = 0; i < threads->n_threads; i++)
+ pthread_cancel(threads->threads[i].thread);
+
+ for (i = 0; i < threads->n_threads; i++)
+ pthread_join(threads->threads[i].thread, NULL);
+
+ free(threads);
+}
diff --git a/src/modules/ray/ray_threads.h b/src/modules/ray/ray_threads.h
new file mode 100644
index 0000000..b4c601d
--- /dev/null
+++ b/src/modules/ray/ray_threads.h
@@ -0,0 +1,30 @@
+#ifndef _RAY_THREADS_H
+#define _RAY_THREADS_H
+
+#include <pthread.h>
+
+typedef struct ray_scene_t ray_scene_t;
+typedef struct ray_camera_t ray_camera_t;
+typedef struct fb_fragment_t fb_fragment_t;
+
+typedef struct ray_thread_t {
+ pthread_t thread;
+ pthread_mutex_t mutex;
+ pthread_cond_t cond;
+ ray_scene_t *scene;
+ ray_camera_t *camera;
+ fb_fragment_t *fragment;
+} ray_thread_t;
+
+typedef struct ray_threads_t {
+ unsigned n_threads;
+ ray_thread_t threads[];
+} ray_threads_t;
+
+
+ray_threads_t * ray_threads_create(unsigned num);
+void ray_threads_destroy(ray_threads_t *threads);
+
+void ray_thread_fragment_submit(ray_thread_t *thread, ray_scene_t *scene, ray_camera_t *camera, fb_fragment_t *fragment);
+void ray_thread_wait_idle(ray_thread_t *thread);
+#endif
diff --git a/src/modules/roto/Makefile.am b/src/modules/roto/Makefile.am
new file mode 100644
index 0000000..08d8522
--- /dev/null
+++ b/src/modules/roto/Makefile.am
@@ -0,0 +1,4 @@
+noinst_LIBRARIES = libroto.a
+libroto_a_SOURCES = roto.c roto.h
+libroto_a_CFLAGS = @ROTOTILLER_CFLAGS@
+libroto_a_CPPFLAGS = @ROTOTILLER_CFLAGS@ -I../../
diff --git a/src/modules/roto/roto.c b/src/modules/roto/roto.c
new file mode 100644
index 0000000..d789f85
--- /dev/null
+++ b/src/modules/roto/roto.c
@@ -0,0 +1,305 @@
+#include <stdint.h>
+#include <inttypes.h>
+#include <math.h>
+
+#include "fb.h"
+#include "rototiller.h"
+
+/* Copyright (C) 2016 Vito Caputo <vcaputo@pengaru.com> */
+
+/* Some defines for the fixed-point stuff in render(). */
+#define FIXED_TRIG_LUT_SIZE 4096 /* size of the cos/sin look-up tables */
+#define FIXED_BITS 11 /* fractional bits */
+#define FIXED_EXP (1 << FIXED_BITS) /* 2^FIXED_BITS */
+#define FIXED_MASK (FIXED_EXP - 1) /* fractional part mask */
+#define FIXED_COS(_rad) costab[(_rad) % FIXED_TRIG_LUT_SIZE]
+#define FIXED_SIN(_rad) sintab[(_rad) % FIXED_TRIG_LUT_SIZE]
+#define FIXED_MULT(_a, _b) (((_a) * (_b)) >> FIXED_BITS)
+#define FIXED_NEW(_i) ((_i) << FIXED_BITS)
+#define FIXED_TO_INT(_f) ((_f) >> FIXED_BITS)
+
+typedef struct color_t {
+ int r, g, b;
+} color_t;
+
+
+/* linearly interpolate between two colors, alpha is fixed-point value 0-FIXED_EXP. */
+static inline color_t lerp_color(color_t *a, color_t *b, int alpha)
+{
+ /* TODO: This could be done without multiplies with a bit of effort,
+ * maybe a simple table mapping integer color deltas to shift values
+ * for shifting alpha which then gets simply added? A table may not even
+ * be necessary, use the order of the delta to derive how much to shift
+ * alpha?
+ */
+ color_t c = {
+ .r = a->r + FIXED_MULT(alpha, b->r - a->r),
+ .g = a->g + FIXED_MULT(alpha, b->g - a->g),
+ .b = a->b + FIXED_MULT(alpha, b->b - a->b),
+ };
+
+ return c;
+}
+
+
+/* Return the bilinearly interpolated color palette[texture[ty][tx]] (Anti-Aliasing) */
+/* tx, ty are fixed-point for fractions, palette colors are also in fixed-point format. */
+static uint32_t bilerp_color(uint8_t texture[256][256], color_t *palette, int tx, int ty)
+{
+ uint8_t itx = FIXED_TO_INT(tx), ity = FIXED_TO_INT(ty);
+ color_t n_color, s_color, color;
+ int x_alpha, y_alpha;
+ uint8_t nw, ne, sw, se;
+
+ /* We need the 4 texels constituting a 2x2 square pattern to interpolate.
+ * A point tx,ty can only intersect one texel; one corner of the 2x2 square.
+ * Where relative to the corner's center the intersection occurs determines which corner has been intersected,
+ * and the other corner texels may then be addressed relative to that corner.
+ * Alpha values must also be determined for both axis, these values describe the position between
+ * the 2x2 texel centers the intersection occurred, aka the weight or bias.
+ * Once the two alpha values are known, linear interpolation between the texel colors is trivial.
+ */
+
+ if ((ty & FIXED_MASK) > (FIXED_EXP >> 1)) {
+ y_alpha = ty & (FIXED_MASK >> 1);
+
+ if ((tx & (FIXED_MASK)) > (FIXED_EXP >> 1)) {
+ nw = texture[ity][itx];
+ ne = texture[ity][(uint8_t)(itx + 1)];
+ sw = texture[(uint8_t)(ity + 1)][itx];
+ se = texture[(uint8_t)(ity + 1)][(uint8_t)(itx + 1)];
+
+ x_alpha = tx & (FIXED_MASK >> 1);
+ } else {
+ ne = texture[ity][itx];
+ nw = texture[ity][(uint8_t)(itx - 1)];
+ se = texture[(uint8_t)(ity + 1)][itx];
+ sw = texture[(uint8_t)(ity + 1)][(uint8_t)(itx - 1)];
+
+ x_alpha = (FIXED_EXP >> 1) + (tx & (FIXED_MASK >> 1));
+ }
+ } else {
+ y_alpha = (FIXED_EXP >> 1) + (ty & (FIXED_MASK >> 1));
+
+ if ((tx & (FIXED_MASK)) > (FIXED_EXP >> 1)) {
+ sw = texture[ity][itx];
+ se = texture[ity][(uint8_t)(itx + 1)];
+ nw = texture[(uint8_t)(ity - 1)][itx];
+ ne = texture[(uint8_t)(ity - 1)][(uint8_t)(itx + 1)];
+
+ x_alpha = tx & (FIXED_MASK >> 1);
+ } else {
+ se = texture[ity][itx];
+ sw = texture[ity][(uint8_t)(itx - 1)];
+ ne = texture[(uint8_t)(ity - 1)][itx];
+ nw = texture[(uint8_t)(ity - 1)][(uint8_t)(itx - 1)];
+
+ x_alpha = (FIXED_EXP >> 1) + (tx & (FIXED_MASK >> 1));
+ }
+ }
+
+ /* Skip interpolation of same colors, a substantial optimization with plain textures like the checker pattern */
+ if (nw == ne) {
+ if (ne == sw && sw == se) {
+ return (FIXED_TO_INT(palette[sw].r) << 16) | (FIXED_TO_INT(palette[sw].g) << 8) | FIXED_TO_INT(palette[sw].b);
+ }
+ n_color = palette[nw];
+ } else {
+ n_color = lerp_color(&palette[nw], &palette[ne], x_alpha);
+ }
+
+ if (sw == se) {
+ s_color = palette[sw];
+ } else {
+ s_color = lerp_color(&palette[sw], &palette[se], x_alpha);
+ }
+
+ color = lerp_color(&n_color, &s_color, y_alpha);
+
+ return (FIXED_TO_INT(color.r) << 16) | (FIXED_TO_INT(color.g) << 8) | FIXED_TO_INT(color.b);
+}
+
+
+static void init_roto(uint8_t texture[256][256], int32_t *costab, int32_t *sintab)
+{
+ int x, y, i;
+
+ /* Generate simple checker pattern texture, nothing clever, feel free to play! */
+ /* If you modify texture on every frame instead of only @ initialization you can
+ * produce some neat output. These values are indexed into palette[] below. */
+ for (y = 0; y < 128; y++) {
+ for (x = 0; x < 128; x++)
+ texture[y][x] = 1;
+ for (; x < 256; x++)
+ texture[y][x] = 0;
+ }
+ for (; y < 256; y++) {
+ for (x = 0; x < 128; x++)
+ texture[y][x] = 0;
+ for (; x < 256; x++)
+ texture[y][x] = 1;
+ }
+
+ /* Generate fixed-point cos & sin LUTs. */
+ for (i = 0; i < FIXED_TRIG_LUT_SIZE; i++) {
+ costab[i] = ((cos((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP);
+ sintab[i] = ((sin((double)2*M_PI*i/FIXED_TRIG_LUT_SIZE))*FIXED_EXP);
+ }
+}
+
+
+/* Draw a rotating checkered 256x256 texture into fragment. (32-bit version) */
+static void roto32(fb_fragment_t *fragment)
+{
+ static int32_t costab[FIXED_TRIG_LUT_SIZE], sintab[FIXED_TRIG_LUT_SIZE];
+ static uint8_t texture[256][256];
+ static int initialized;
+ static color_t palette[2];
+ static unsigned r, rr;
+
+ int y_cos_r, y_sin_r, x_cos_r, x_sin_r, x_cos_r_init, x_sin_r_init, cos_r, sin_r;
+ int x, y, stride = fragment->stride / 4, width = fragment->width, height = fragment->height;
+ uint32_t *buf = fragment->buf;
+
+ if (!initialized) {
+ initialized = 1;
+
+ init_roto(texture, costab, sintab);
+ }
+
+ /* This is all done using fixed-point in the hopes of being faster, and yes assumptions
+ * are being made WRT the overflow of tx/ty as well, only tested on x86_64. */
+ cos_r = FIXED_COS(r);
+ sin_r = FIXED_SIN(r);
+
+ /* Vary the colors, this is just a mashup of sinusoidal rgb values. */
+ palette[0].r = (FIXED_MULT(FIXED_COS(rr), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[0].g = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[0].b = (FIXED_MULT(FIXED_COS(rr / 3), FIXED_NEW(127)) + FIXED_NEW(128));
+
+ palette[1].r = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[1].g = (FIXED_MULT(FIXED_COS(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[1].b = (FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(127)) + FIXED_NEW(128));
+
+ /* The dimensions are cut in half and negated to center the rotation. */
+ /* The [xy]_{sin,cos}_r variables are accumulators to replace multiplication with addition. */
+ x_cos_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), cos_r);
+ x_sin_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), sin_r);
+
+ y_cos_r = FIXED_MULT(-FIXED_NEW((height / 2)), cos_r);
+ y_sin_r = FIXED_MULT(-FIXED_NEW((height / 2)), sin_r);
+
+ for (y = 0; y < height; y++) {
+
+ x_cos_r = x_cos_r_init;
+ x_sin_r = x_sin_r_init;
+
+ for (x = 0; x < width; x++, buf++) {
+ *buf = bilerp_color(texture, palette, x_sin_r - y_cos_r, y_sin_r + x_cos_r);
+
+ x_cos_r += cos_r;
+ x_sin_r += sin_r;
+ }
+
+ buf += stride;
+ y_cos_r += cos_r;
+ y_sin_r += sin_r;
+ }
+
+ // This governs the rotation and color cycle.
+ r += FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(16)));
+ rr += 2;
+}
+
+
+/* Draw a rotating checkered 256x256 texture into fragment. (64-bit version) */
+static void roto64(fb_fragment_t *fragment)
+{
+ static int32_t costab[FIXED_TRIG_LUT_SIZE], sintab[FIXED_TRIG_LUT_SIZE];
+ static uint8_t texture[256][256];
+ static int initialized;
+ static color_t palette[2];
+ static unsigned r, rr;
+
+ int y_cos_r, y_sin_r, x_cos_r, x_sin_r, x_cos_r_init, x_sin_r_init, cos_r, sin_r;
+ int x, y, stride = fragment->stride / 8, width = fragment->width, height = fragment->height;
+ uint64_t *buf = (uint64_t *)fragment->buf;
+
+ if (!initialized) {
+ initialized = 1;
+
+ init_roto(texture, costab, sintab);
+ }
+
+ /* This is all done using fixed-point in the hopes of being faster, and yes assumptions
+ * are being made WRT the overflow of tx/ty as well, only tested on x86_64. */
+ cos_r = FIXED_COS(r);
+ sin_r = FIXED_SIN(r);
+
+ /* Vary the colors, this is just a mashup of sinusoidal rgb values. */
+ palette[0].r = (FIXED_MULT(FIXED_COS(rr), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[0].g = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[0].b = (FIXED_MULT(FIXED_COS(rr / 3), FIXED_NEW(127)) + FIXED_NEW(128));
+
+ palette[1].r = (FIXED_MULT(FIXED_SIN(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[1].g = (FIXED_MULT(FIXED_COS(rr / 2), FIXED_NEW(127)) + FIXED_NEW(128));
+ palette[1].b = (FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(127)) + FIXED_NEW(128));
+
+ /* The dimensions are cut in half and negated to center the rotation. */
+ /* The [xy]_{sin,cos}_r variables are accumulators to replace multiplication with addition. */
+ x_cos_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), cos_r);
+ x_sin_r_init = FIXED_MULT(-FIXED_NEW((width / 2)), sin_r);
+
+ y_cos_r = FIXED_MULT(-FIXED_NEW((height / 2)), cos_r);
+ y_sin_r = FIXED_MULT(-FIXED_NEW((height / 2)), sin_r);
+
+ width /= 2; /* Since we're processing 64-bit words (2 pixels) at a time */
+
+ for (y = 0; y < height; y++) {
+
+ x_cos_r = x_cos_r_init;
+ x_sin_r = x_sin_r_init;
+
+ for (x = 0; x < width; x++, buf++) {
+ uint64_t p;
+
+ p = bilerp_color(texture, palette, x_sin_r - y_cos_r, y_sin_r + x_cos_r);
+
+ x_cos_r += cos_r;
+ x_sin_r += sin_r;
+
+ p |= (uint64_t)(bilerp_color(texture, palette, x_sin_r - y_cos_r, y_sin_r + x_cos_r)) << 32;
+
+ *buf = p;
+
+ x_cos_r += cos_r;
+ x_sin_r += sin_r;
+ }
+
+ buf += stride;
+ y_cos_r += cos_r;
+ y_sin_r += sin_r;
+ }
+
+ // This governs the rotation and color cycle.
+ r += FIXED_TO_INT(FIXED_MULT(FIXED_SIN(rr), FIXED_NEW(16)));
+ rr += 2;
+}
+
+
+rototiller_renderer_t roto32_renderer = {
+ .render = roto32,
+ .name = "roto32",
+ .description = "Anti-aliased tiled texture rotation (32-bit)",
+ .author = "Vito Caputo <vcaputo@pengaru.com>",
+ .license = "GPLv2",
+};
+
+
+rototiller_renderer_t roto64_renderer = {
+ .render = roto64,
+ .name = "roto64",
+ .description = "Anti-aliased tiled texture rotation (64-bit)",
+ .author = "Vito Caputo <vcaputo@pengaru.com>",
+ .license = "GPLv2",
+};
diff --git a/src/modules/roto/roto.h b/src/modules/roto/roto.h
new file mode 100644
index 0000000..84a66a9
--- /dev/null
+++ b/src/modules/roto/roto.h
@@ -0,0 +1,9 @@
+#ifndef _ROTO_H
+#define _ROTO_H
+
+#include "fb.h"
+
+void roto64(fb_fragment_t *fragment);
+void roto32(fb_fragment_t *fragment);
+
+#endif
diff --git a/src/modules/sparkler/Makefile.am b/src/modules/sparkler/Makefile.am
new file mode 100644
index 0000000..13d8e8a
--- /dev/null
+++ b/src/modules/sparkler/Makefile.am
@@ -0,0 +1,4 @@
+noinst_LIBRARIES = libsparkler.a
+libsparkler_a_SOURCES = bsp.c bsp.h burst.c chunker.c chunker.h container.h draw.h list.h particle.c particle.h particles.c particles.h rocket.c simple.c spark.c sparkler.c sparkler.h v3f.h xplode.c
+libsparkler_a_CFLAGS = @ROTOTILLER_CFLAGS@ -ffast-math
+libsparkler_a_CPPFLAGS = @ROTOTILLER_CFLAGS@ -I../../
diff --git a/src/modules/sparkler/bsp.c b/src/modules/sparkler/bsp.c
new file mode 100644
index 0000000..381e922
--- /dev/null
+++ b/src/modules/sparkler/bsp.c
@@ -0,0 +1,584 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "bsp.h"
+
+
+/* octree-based bsp for faster proximity searches */
+/* meanings:
+ * octrant = "octo" analog of a quadrant, an octree is a quadtree with an additional dimension (Z/3d)
+ * bv = bounding volume
+ * bsp = binary space partition
+ * occupant = the things being indexed by the bsp (e.g. a particle, or its position)
+ */
+
+
+/* FIXME: these are not tuned at all, and should really all be parameters to bsp_new() instead */
+#define BSP_GROWBY 16
+#define BSP_MAX_OCCUPANTS 64
+#define BSP_MAX_DEPTH 16
+
+#define MAX(_a, _b) (_a > _b ? _a : _b)
+#define MIN(_a, _b) (_a < _b ? _a : _b)
+
+
+struct bsp_node_t {
+ v3f_t center; /* center point about which the bounding volume's 3d-space is divided */
+ bsp_node_t *parent; /* parent bounding volume, NULL when root node */
+ bsp_node_t *octrants; /* NULL when a leaf, otherwise an array of 8 bsp_node_t's */
+ list_head_t occupants; /* list of occupants in this volume when a leaf node */
+ unsigned n_occupants; /* number of ^^ */
+};
+
+#define OCTRANTS \
+ octrant(OCT_XL_YL_ZL, (1 << 2 | 1 << 1 | 1)) \
+ octrant(OCT_XR_YL_ZL, ( 1 << 1 | 1)) \
+ octrant(OCT_XL_YR_ZL, (1 << 2 | 1)) \
+ octrant(OCT_XR_YR_ZL, ( 1)) \
+ octrant(OCT_XL_YL_ZR, (1 << 2 | 1 << 1 )) \
+ octrant(OCT_XR_YL_ZR, ( 1 << 1 )) \
+ octrant(OCT_XL_YR_ZR, (1 << 2 )) \
+ octrant(OCT_XR_YR_ZR, 0)
+
+#define octrant(_sym, _val) _sym = _val,
+typedef enum _octrant_idx_t {
+ OCTRANTS
+} octrant_idx_t;
+#undef octrant
+
+/* bsp lookup state, encapsulated for preservation across composite
+ * lookup-dependent operations, so they can potentially avoid having
+ * to redo the lookup. i.e. lookup caching.
+ */
+typedef struct _bsp_lookup_t {
+ int depth;
+ v3f_t left;
+ v3f_t right;
+ bsp_node_t *bv;
+ octrant_idx_t oidx;
+} bsp_lookup_t;
+
+struct bsp_t {
+ bsp_node_t root;
+ list_head_t free;
+ bsp_lookup_t lookup_cache;
+};
+
+
+static inline const char * octstr(octrant_idx_t oidx)
+{
+#define octrant(_sym, _val) #_sym,
+ static const char *octrant_strs[] = {
+ OCTRANTS
+ };
+#undef octrant
+
+ return octrant_strs[oidx];
+}
+
+
+static inline void _bsp_print(bsp_node_t *node)
+{
+ static int depth = 0;
+
+ fprintf(stderr, "%-*s %i: %p\n", depth, " ", depth, node);
+ if (node->octrants) {
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ fprintf(stderr, "%-*s %i: %s: %p\n", depth, " ", depth, octstr(i), &node->octrants[i]);
+ depth++;
+ _bsp_print(&node->octrants[i]);
+ depth--;
+ }
+ }
+}
+
+
+/* Print a bsp tree to stderr (debugging) */
+void bsp_print(bsp_t *bsp)
+{
+ _bsp_print(&bsp->root);
+}
+
+
+/* Initialize the lookup cache to the root */
+static inline void bsp_init_lookup_cache(bsp_t *bsp) {
+ bsp->lookup_cache.bv = &bsp->root;
+ bsp->lookup_cache.depth = 0;
+ v3f_set(&bsp->lookup_cache.left, -1.0, -1.0, -1.0); /* TODO: the bsp AABB should be supplied to bsp_new() */
+ v3f_set(&bsp->lookup_cache.right, 1.0, 1.0, 1.0);
+}
+
+
+/* Invalidate/reset the bsp's lookup cache TODO: make conditional on a supplied node being cached? */
+static inline void bsp_invalidate_lookup_cache(bsp_t *bsp) {
+ if (bsp->lookup_cache.bv != &bsp->root) {
+ bsp_init_lookup_cache(bsp);
+ }
+}
+
+
+/* Create a new bsp octree. */
+bsp_t * bsp_new(void)
+{
+ bsp_t *bsp;
+
+ bsp = calloc(1, sizeof(bsp_t));
+ if (!bsp) {
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&bsp->root.occupants);
+ INIT_LIST_HEAD(&bsp->free);
+ bsp_init_lookup_cache(bsp);
+
+ return bsp;
+}
+
+
+/* Free a bsp octree */
+void bsp_free(bsp_t *bsp)
+{
+ /* TODO: free everything ... */
+ free(bsp);
+}
+
+
+/* lookup a position's containing leaf node in the bsp tree, store resultant lookup state in *lookup_res */
+static inline void bsp_lookup_position(bsp_t *bsp, bsp_node_t *root, v3f_t *position, bsp_lookup_t *lookup_res)
+{
+ bsp_lookup_t res = bsp->lookup_cache;
+
+ if (res.bv->parent) {
+ /* When starting from a cached (non-root) lookup, we must verify our position falls within the cached bv */
+ if (position->x < res.left.x || position->x > res.right.x ||
+ position->y < res.left.y || position->y > res.right.y ||
+ position->z < res.left.z || position->z > res.right.z) {
+ bsp_invalidate_lookup_cache(bsp);
+ res = bsp->lookup_cache;
+ }
+ }
+
+ while (res.bv->octrants) {
+ res.oidx = OCT_XR_YR_ZR;
+ if (position->x <= res.bv->center.x) {
+ res.oidx |= (1 << 2);
+ res.right.x = res.bv->center.x;
+ } else {
+ res.left.x = res.bv->center.x;
+ }
+
+ if (position->y <= res.bv->center.y) {
+ res.oidx |= (1 << 1);
+ res.right.y = res.bv->center.y;
+ } else {
+ res.left.y = res.bv->center.y;
+ }
+
+ if (position->z <= res.bv->center.z) {
+ res.oidx |= 1;
+ res.right.z = res.bv->center.z;
+ } else {
+ res.left.z = res.bv->center.z;
+ }
+
+ res.bv = &res.bv->octrants[res.oidx];
+ res.depth++;
+ }
+
+ *lookup_res = bsp->lookup_cache = res;
+}
+
+
+/* Add an occupant to a bsp tree, use provided node lookup *l if supplied */
+static inline void _bsp_add_occupant(bsp_t *bsp, bsp_occupant_t *occupant, v3f_t *position, bsp_lookup_t *l)
+{
+ bsp_lookup_t _lookup;
+
+ /* if no explicitly cached lookup result was provided, perform the lookup now (which may still be cached). */
+ if (!l) {
+ l = &_lookup;
+ bsp_lookup_position(bsp, &bsp->root, position, l);
+ }
+
+ assert(l);
+ assert(l->bv);
+
+ occupant->position = position;
+
+#define map_occupant2octrant(_occupant, _bv, _octrant) \
+ _octrant = OCT_XR_YR_ZR; \
+ if (_occupant->position->x <= _bv->center.x) { \
+ _octrant |= (1 << 2); \
+ } \
+ if (_occupant->position->y <= _bv->center.y) { \
+ _octrant |= (1 << 1); \
+ } \
+ if (_occupant->position->z <= _bv->center.z) { \
+ _octrant |= 1; \
+ }
+
+ if (l->bv->n_occupants >= BSP_MAX_OCCUPANTS && l->depth < BSP_MAX_DEPTH) {
+ int i;
+ list_head_t *t, *_t;
+ bsp_node_t *bv = l->bv;
+
+ /* bv is full and shallow enough, subdivide it. */
+
+ /* ensure the free list has something for us */
+ if (list_empty(&bsp->free)) {
+ bsp_node_t *t;
+
+ /* TODO: does using the chunker instead make sense here? */
+ t = calloc(sizeof(bsp_node_t), 8 * BSP_GROWBY);
+ for (i = 0; i < 8 * BSP_GROWBY; i += 8) {
+ list_add(&t[i].occupants, &bsp->free);
+ }
+ }
+
+ /* take an octrants array from the free list */
+ bv->octrants = list_entry(bsp->free.next, bsp_node_t, occupants);
+ list_del(&bv->octrants[0].occupants);
+
+ /* initialize the octrants */
+ for (i = 0; i < 8; i++) {
+ INIT_LIST_HEAD(&bv->octrants[i].occupants);
+ bv->octrants[i].n_occupants = 0;
+ bv->octrants[i].parent = bv;
+ bv->octrants[i].octrants = NULL;
+ }
+
+ /* set the center point in each octrant which places the partitioning hyperplane */
+ /* XXX: note this is pretty unreadable due to reusing the earlier computed values
+ * where the identical computation is required.
+ */
+ bv->octrants[OCT_XR_YR_ZR].center.x = (l->right.x - bv->center.x) * .5f + bv->center.x;
+ bv->octrants[OCT_XR_YR_ZR].center.y = (l->right.y - bv->center.y) * .5f + bv->center.y;
+ bv->octrants[OCT_XR_YR_ZR].center.z = (l->right.z - bv->center.z) * .5f + bv->center.z;
+
+ bv->octrants[OCT_XR_YR_ZL].center.x = bv->octrants[OCT_XR_YR_ZR].center.x;
+ bv->octrants[OCT_XR_YR_ZL].center.y = bv->octrants[OCT_XR_YR_ZR].center.y;
+ bv->octrants[OCT_XR_YR_ZL].center.z = (bv->center.z - l->left.z) * .5f + l->left.z;
+
+ bv->octrants[OCT_XR_YL_ZR].center.x = bv->octrants[OCT_XR_YR_ZR].center.x;
+ bv->octrants[OCT_XR_YL_ZR].center.y = (bv->center.y - l->left.y) * .5f + l->left.y;
+ bv->octrants[OCT_XR_YL_ZR].center.z = bv->octrants[OCT_XR_YR_ZR].center.z;
+
+ bv->octrants[OCT_XR_YL_ZL].center.x = bv->octrants[OCT_XR_YR_ZR].center.x;
+ bv->octrants[OCT_XR_YL_ZL].center.y = bv->octrants[OCT_XR_YL_ZR].center.y;
+ bv->octrants[OCT_XR_YL_ZL].center.z = bv->octrants[OCT_XR_YR_ZL].center.z;
+
+ bv->octrants[OCT_XL_YR_ZR].center.x = (bv->center.x - l->left.x) * .5f + l->left.x;
+ bv->octrants[OCT_XL_YR_ZR].center.y = bv->octrants[OCT_XR_YR_ZR].center.y;
+ bv->octrants[OCT_XL_YR_ZR].center.z = bv->octrants[OCT_XR_YR_ZR].center.z;
+
+ bv->octrants[OCT_XL_YR_ZL].center.x = bv->octrants[OCT_XL_YR_ZR].center.x;
+ bv->octrants[OCT_XL_YR_ZL].center.y = bv->octrants[OCT_XR_YR_ZR].center.y;
+ bv->octrants[OCT_XL_YR_ZL].center.z = bv->octrants[OCT_XR_YR_ZL].center.z;
+
+ bv->octrants[OCT_XL_YL_ZR].center.x = bv->octrants[OCT_XL_YR_ZR].center.x;
+ bv->octrants[OCT_XL_YL_ZR].center.y = bv->octrants[OCT_XR_YL_ZR].center.y;
+ bv->octrants[OCT_XL_YL_ZR].center.z = bv->octrants[OCT_XR_YR_ZR].center.z;
+
+ bv->octrants[OCT_XL_YL_ZL].center.x = bv->octrants[OCT_XL_YR_ZR].center.x;
+ bv->octrants[OCT_XL_YL_ZL].center.y = bv->octrants[OCT_XR_YL_ZR].center.y;
+ bv->octrants[OCT_XL_YL_ZL].center.z = bv->octrants[OCT_XR_YR_ZL].center.z;
+
+ /* migrate the occupants into the appropriate octrants */
+ list_for_each_safe(t, _t, &bv->occupants) {
+ octrant_idx_t oidx;
+ bsp_occupant_t *o = list_entry(t, bsp_occupant_t, occupants);
+
+ map_occupant2octrant(o, bv, oidx);
+ list_move(t, &bv->octrants[oidx].occupants);
+ o->leaf = &bv->octrants[oidx];
+ bv->octrants[oidx].n_occupants++;
+ }
+ bv->n_occupants = 0;
+
+ /* a new leaf assumes the bv position for the occupant to be added into */
+ map_occupant2octrant(occupant, bv, l->oidx);
+ l->bv = &bv->octrants[l->oidx];
+ l->depth++;
+ }
+
+#undef map_occupant2octrant
+
+ occupant->leaf = l->bv;
+ list_add(&occupant->occupants, &l->bv->occupants);
+ l->bv->n_occupants++;
+
+ assert(occupant->leaf);
+}
+
+
+/* add an occupant to a bsp tree */
+void bsp_add_occupant(bsp_t *bsp, bsp_occupant_t *occupant, v3f_t *position)
+{
+ _bsp_add_occupant(bsp, occupant, position, NULL);
+}
+
+
+/* Delete an occupant from a bsp tree.
+ * Set reservation to prevent potentially freeing a node made empty by our delete that
+ * we have a reference to (i.e. a cached lookup result, see bsp_move_occupant()).
+ */
+static inline void _bsp_delete_occupant(bsp_t *bsp, bsp_occupant_t *occupant, bsp_node_t *reservation)
+{
+ if (occupant->leaf->octrants) {
+ fprintf(stderr, "BUG: deleting occupant(%p) from non-leaf bv(%p)\n", occupant, occupant->leaf);
+ }
+
+ /* delete the occupant */
+ list_del(&occupant->occupants);
+ occupant->leaf->n_occupants--;
+
+ if (list_empty(&occupant->leaf->occupants)) {
+ bsp_node_t *parent_bv;
+
+ if (occupant->leaf->n_occupants) {
+ fprintf(stderr, "BUG: bv_occupants empty but n_occupants=%u\n", occupant->leaf->n_occupants);
+ }
+
+ /* leaf is now empty, since nodes are allocated as clusters of 8, they aren't freed unless all nodes in the cluster are empty.
+ * Determine if they're all empty, and free the parent's octrants as a set.
+ * Repeat this process up the chain of parents, repeatedly converting empty parents into leaf nodes.
+ * TODO: maybe just use the chunker instead?
+ */
+
+ for (parent_bv = occupant->leaf->parent; parent_bv && parent_bv != reservation; parent_bv = parent_bv->parent) {
+ int i;
+
+ /* are _all_ the parent's octrants freeable? */
+ for (i = 0; i < 8; i++) {
+ if (&parent_bv->octrants[i] == reservation ||
+ parent_bv->octrants[i].octrants ||
+ !list_empty(&parent_bv->octrants[i].occupants)) {
+ goto _out;
+ }
+ }
+
+ /* "freeing" really just entails putting the octrants cluster of nodes onto the free list */
+ list_add(&parent_bv->octrants[0].occupants, &bsp->free);
+ parent_bv->octrants = NULL;
+ bsp_invalidate_lookup_cache(bsp);
+ }
+ }
+
+_out:
+ occupant->leaf = NULL;
+}
+
+
+/* Delete an occupant from a bsp tree. */
+void bsp_delete_occupant(bsp_t *bsp, bsp_occupant_t *occupant)
+{
+ _bsp_delete_occupant(bsp, occupant, NULL);
+}
+
+
+/* Move an occupant within a bsp tree to a new position */
+void bsp_move_occupant(bsp_t *bsp, bsp_occupant_t *occupant, v3f_t *position)
+{
+ bsp_lookup_t lookup_res;
+
+ if (v3f_equal(occupant->position, position)) {
+ return;
+ }
+
+ /* TODO: now that there's a cache maintained in bsp->lookup_cache as well,
+ * this feels a bit vestigial, see about consolidating things. We still
+ * need to be able to pin lookup_res.bv in the delete, but why not just use
+ * the one in bsp->lookup_cache.bv then stop having lookup_position return
+ * a result at all???? this bsp isn't concurrent/threaded, so it doens't
+ * really matter.
+ */
+ bsp_lookup_position(bsp, &bsp->root, occupant->position, &lookup_res);
+ if (lookup_res.bv == occupant->leaf) {
+ /* leaf unchanged, do nothing past lookup. */
+ occupant->position = position;
+ return;
+ }
+
+ _bsp_delete_occupant(bsp, occupant, lookup_res.bv);
+ _bsp_add_occupant(bsp, occupant, position, &lookup_res);
+}
+
+
+static inline float square(float v)
+{
+ return v * v;
+}
+
+
+typedef enum overlaps_t {
+ OVERLAPS_NONE, /* objects are completely separated */
+ OVERLAPS_PARTIALLY, /* objects surfaces one another */
+ OVERLAPS_A_IN_B, /* first object is fully within the second */
+ OVERLAPS_B_IN_A, /* second object is fully within the first */
+} overlaps_t;
+
+
+/* Returns wether the axis-aligned bounding box (AABB) overlaps the sphere.
+ * Absolute vs. partial overlaps are distinguished, since it's an important optimization
+ * to know if the sphere falls entirely within one partition of the octree.
+ */
+static inline overlaps_t aabb_overlaps_sphere(v3f_t *aabb_min, v3f_t *aabb_max, v3f_t *sphere_center, float sphere_radius)
+{
+ /* This implementation is based on James Arvo's from Graphics Gems pg. 335 */
+ float r2 = square(sphere_radius);
+ float dface = INFINITY;
+ float dmin = 0;
+ float dmax = 0;
+ float a, b;
+
+#define per_dimension(_center, _box_max, _box_min) \
+ a = square(_center - _box_min); \
+ b = square(_center - _box_max); \
+ \
+ dmax += MAX(a, b); \
+ if (_center >= _box_min && _center <= _box_max) { \
+ /* sphere center within box */ \
+ dface = MIN(dface, MIN(a, b)); \
+ } else { \
+ /* sphere center outside the box */ \
+ dface = 0; \
+ dmin += MIN(a, b); \
+ }
+
+ per_dimension(sphere_center->x, aabb_max->x, aabb_min->x);
+ per_dimension(sphere_center->y, aabb_max->y, aabb_min->y);
+ per_dimension(sphere_center->z, aabb_max->z, aabb_min->z);
+
+ if (dmax < r2) {
+ /* maximum distance to box smaller than radius, box is inside
+ * the sphere */
+ return OVERLAPS_A_IN_B;
+ }
+
+ if (dface > r2) {
+ /* sphere center is within box (non-zero dface), and dface is
+ * greater than sphere diameter, sphere is inside the box. */
+ return OVERLAPS_B_IN_A;
+ }
+
+ if (dmin <= r2) {
+ /* minimum distance from sphere center to box is smaller than
+ * sphere's radius, surfaces intersect */
+ return OVERLAPS_PARTIALLY;
+ }
+
+ return OVERLAPS_NONE;
+}
+
+
+typedef struct bsp_search_sphere_t {
+ v3f_t *center;
+ float radius_min;
+ float radius_max;
+ void (*cb)(bsp_t *, list_head_t *, void *);
+ void *cb_data;
+} bsp_search_sphere_t;
+
+
+static overlaps_t _bsp_search_sphere(bsp_t *bsp, bsp_node_t *node, bsp_search_sphere_t *search, v3f_t *aabb_min, v3f_t *aabb_max)
+{
+ overlaps_t res;
+ v3f_t oaabb_min, oaabb_max;
+
+ /* if the radius_max search doesn't overlap aabb_min:aabb_max at all, simply return. */
+ res = aabb_overlaps_sphere(aabb_min, aabb_max, search->center, search->radius_max);
+ if (res == OVERLAPS_NONE) {
+ return res;
+ }
+
+ /* if the radius_max absolutely overlaps the AABB, we must see if the AABB falls entirely within radius_min so we can skip it. */
+ if (res == OVERLAPS_A_IN_B) {
+ res = aabb_overlaps_sphere(aabb_min, aabb_max, search->center, search->radius_min);
+ if (res == OVERLAPS_A_IN_B) {
+ /* AABB is entirely within radius_min, skip it. */
+ return OVERLAPS_NONE;
+ }
+
+ if (res == OVERLAPS_NONE) {
+ /* radius_min didn't overlap, radius_max overlapped aabb 100%, it's entirely within the range. */
+ res = OVERLAPS_A_IN_B;
+ } else {
+ /* radius_min overlapped partially.. */
+ res = OVERLAPS_PARTIALLY;
+ }
+ }
+
+ /* if node is a leaf, call search->cb with the occupants, then return. */
+ if (!node->octrants) {
+ search->cb(bsp, &node->occupants, search->cb_data);
+ return res;
+ }
+
+ /* node is a parent, recur on each octrant with appropriately adjusted aabb_min:aabb_max values */
+ /* if any of the octrants absolutely overlaps the search sphere, skip the others by returning. */
+#define search_octrant(_oid, _aabb_min, _aabb_max) \
+ res = _bsp_search_sphere(bsp, &node->octrants[_oid], search, _aabb_min, _aabb_max); \
+ if (res == OVERLAPS_B_IN_A) { \
+ return res; \
+ }
+
+ /* OCT_XL_YL_ZL and OCT_XR_YR_ZR AABBs don't require tedious composition */
+ search_octrant(OCT_XL_YL_ZL, aabb_min, &node->center);
+ search_octrant(OCT_XR_YR_ZR, &node->center, aabb_max);
+
+ /* the rest are stitched together requiring temp storage and tedium */
+ v3f_set(&oaabb_min, node->center.x, aabb_min->y, aabb_min->z);
+ v3f_set(&oaabb_max, aabb_max->x, node->center.y, node->center.z);
+ search_octrant(OCT_XR_YL_ZL, &oaabb_min, &oaabb_max);
+
+ v3f_set(&oaabb_min, aabb_min->x, node->center.y, aabb_min->z);
+ v3f_set(&oaabb_max, node->center.x, aabb_max->y, node->center.z);
+ search_octrant(OCT_XL_YR_ZL, &oaabb_min, &oaabb_max);
+
+ v3f_set(&oaabb_min, node->center.x, node->center.y, aabb_min->z);
+ v3f_set(&oaabb_max, aabb_max->x, aabb_max->y, node->center.z);
+ search_octrant(OCT_XR_YR_ZL, &oaabb_min, &oaabb_max);
+
+ v3f_set(&oaabb_min, aabb_min->x, aabb_min->y, node->center.z);
+ v3f_set(&oaabb_max, node->center.x, node->center.y, aabb_max->z);
+ search_octrant(OCT_XL_YL_ZR, &oaabb_min, &oaabb_max);
+
+ v3f_set(&oaabb_min, node->center.x, aabb_min->y, node->center.z);
+ v3f_set(&oaabb_max, aabb_max->x, node->center.y, aabb_max->z);
+ search_octrant(OCT_XR_YL_ZR, &oaabb_min, &oaabb_max);
+
+ v3f_set(&oaabb_min, aabb_min->x, node->center.y, node->center.z);
+ v3f_set(&oaabb_max, node->center.x, aabb_max->y, aabb_max->z);
+ search_octrant(OCT_XL_YR_ZR, &oaabb_min, &oaabb_max);
+
+#undef search_octrant
+
+ /* since early on an OVERLAPS_NONE short-circuits the function, and
+ * OVERLAPS_ABSOLUTE also causes short-circuits, if we arrive here it's
+ * a partial overlap
+ */
+ return OVERLAPS_PARTIALLY;
+}
+
+
+/* search the bsp tree for leaf nodes which intersect the space between radius_min and radius_max of a sphere @ center */
+/* for every leaf node found to intersect the sphere, cb is called with the leaf node's occupants list head */
+/* the callback cb must then further filter the occupants as necessary. */
+void bsp_search_sphere(bsp_t *bsp, v3f_t *center, float radius_min, float radius_max, void (*cb)(bsp_t *, list_head_t *, void *), void *cb_data)
+{
+ bsp_search_sphere_t search = {
+ .center = center,
+ .radius_min = radius_min,
+ .radius_max = radius_max,
+ .cb = cb,
+ .cb_data = cb_data,
+ };
+ v3f_t aabb_min = v3f_init(-1.0f, -1.0f, -1.0f);
+ v3f_t aabb_max = v3f_init(1.0f, 1.0f, 1.0f);
+
+ _bsp_search_sphere(bsp, &bsp->root, &search, &aabb_min, &aabb_max);
+}
diff --git a/src/modules/sparkler/bsp.h b/src/modules/sparkler/bsp.h
new file mode 100644
index 0000000..f5ce303
--- /dev/null
+++ b/src/modules/sparkler/bsp.h
@@ -0,0 +1,28 @@
+#ifndef _BSP_H
+#define _BSP_H
+
+#include <stdint.h>
+
+#include "list.h"
+#include "v3f.h"
+
+typedef struct bsp_t bsp_t;
+typedef struct bsp_node_t bsp_node_t;
+
+/* Embed this in anything you want spatially indexed by the bsp tree. */
+/* TODO: it would be nice to make this opaque, but it's a little annoying. */
+typedef struct bsp_occupant_t {
+ bsp_node_t *leaf; /* leaf node containing this occupant */
+ list_head_t occupants; /* node on containing leaf node's list of occupants */
+ v3f_t *position; /* position of occupant to be partitioned */
+} bsp_occupant_t;
+
+bsp_t * bsp_new(void);
+void bsp_free(bsp_t *bsp);
+void bsp_print(bsp_t *bsp);
+void bsp_add_occupant(bsp_t *bsp, bsp_occupant_t *occupant, v3f_t *position);
+void bsp_delete_occupant(bsp_t *bsp, bsp_occupant_t *occupant);
+void bsp_move_occupant(bsp_t *bsp, bsp_occupant_t *occupant, v3f_t *position);
+void bsp_search_sphere(bsp_t *bsp, v3f_t *center, float radius_min, float radius_max, void (*cb)(bsp_t *, list_head_t *, void *), void *cb_data);
+
+#endif
diff --git a/src/modules/sparkler/burst.c b/src/modules/sparkler/burst.c
new file mode 100644
index 0000000..828ca02
--- /dev/null
+++ b/src/modules/sparkler/burst.c
@@ -0,0 +1,111 @@
+#include <stdlib.h>
+
+#include "bsp.h"
+#include "container.h"
+#include "particle.h"
+#include "particles.h"
+
+
+/* a "burst" (shockwave) particle type */
+/* this doesn't draw anything, it just pushes neighbors away in an increasing radius */
+
+#define BURST_FORCE 0.01f
+#define BURST_MAX_LIFETIME 8
+
+typedef struct _burst_ctxt_t {
+ int longevity;
+ int lifetime;
+} burst_ctxt_t;
+
+
+static int burst_init(particles_t *particles, particle_t *p)
+{
+ burst_ctxt_t *ctxt = p->ctxt;
+
+ ctxt->longevity = ctxt->lifetime = BURST_MAX_LIFETIME;
+ p->props->velocity = 0; /* burst should be stationary */
+ p->props->mass = 0; /* no mass prevents gravity's effects */
+
+ return 1;
+}
+
+
+static inline void thrust_part(particle_t *burst, particle_t *victim, float distance_sq)
+{
+ v3f_t direction = v3f_sub(&victim->props->position, &burst->props->position);
+
+ /* TODO: normalize is expensive, see about removing these. */
+ direction = v3f_normalize(&direction);
+ victim->props->direction = v3f_add(&victim->props->direction, &direction);
+ victim->props->direction = v3f_normalize(&victim->props->direction);
+
+ victim->props->velocity += BURST_FORCE;
+}
+
+
+typedef struct burst_sphere_t {
+ particle_t *center;
+ float radius_min;
+ float radius_max;
+} burst_sphere_t;
+
+
+static void burst_cb(bsp_t *bsp, list_head_t *occupants, void *_s)
+{
+ burst_sphere_t *s = _s;
+ bsp_occupant_t *o;
+ float rmin_sq = s->radius_min * s->radius_min;
+ float rmax_sq = s->radius_max * s->radius_max;
+
+ /* XXX: to avoid having a callback per-particle, bsp_occupant_t was
+ * moved to the public particle, and the particle-specific
+ * implementations directly perform bsp-accelerated searches. Another
+ * wart caused by this is particles_bsp().
+ */
+ list_for_each_entry(o, occupants, occupants) {
+ particle_t *p = container_of(o, particle_t, occupant);
+ float d_sq;
+
+ if (p == s->center) {
+ /* leave ourselves alone */
+ continue;
+ }
+
+ d_sq = v3f_distance_sq(&s->center->props->position, &p->props->position);
+
+ if (d_sq > rmin_sq && d_sq < rmax_sq) {
+ /* displace the part relative to the burst origin */
+ thrust_part(s->center, p, d_sq);
+ }
+
+ }
+}
+
+
+static particle_status_t burst_sim(particles_t *particles, particle_t *p)
+{
+ burst_ctxt_t *ctxt = p->ctxt;
+ bsp_t *bsp = particles_bsp(particles); /* XXX see note above about bsp_occupant_t */
+ burst_sphere_t s;
+
+ if (!ctxt->longevity || (ctxt->longevity--) <= 0) {
+ return PARTICLE_DEAD;
+ }
+
+ /* affect neighbors for the shock-wave */
+ s.radius_min = (1.0f - ((float)ctxt->longevity / ctxt->lifetime)) * 0.075f;
+ s.radius_max = s.radius_min + .01f;
+ s.center = p;
+ bsp_search_sphere(bsp, &p->props->position, s.radius_min, s.radius_max, burst_cb, &s);
+
+ return PARTICLE_ALIVE;
+}
+
+
+particle_ops_t burst_ops = {
+ .context_size = sizeof(burst_ctxt_t),
+ .sim = burst_sim,
+ .init = burst_init,
+ .draw = NULL,
+ .cleanup = NULL,
+ };
diff --git a/src/modules/sparkler/chunker.c b/src/modules/sparkler/chunker.c
new file mode 100644
index 0000000..ca072eb
--- /dev/null
+++ b/src/modules/sparkler/chunker.c
@@ -0,0 +1,225 @@
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "chunker.h"
+#include "container.h"
+#include "list.h"
+
+/* Everything associated with the particles tends to be short-lived.
+ *
+ * They come and go frequently in large numbers. This implements a very basic
+ * chunked allocator which prioritizes efficient allocation and freeing over
+ * low waste of memory. We malloc chunks at a time, doling out elements from
+ * the chunk sequentially as requested until the chunk is cannot fulfill an
+ * allocation, then we just retire the chunk, add a new chunk and continue.
+ *
+ * When allocations are freed, we simply decrement the refcount for its chunk,
+ * leaving the chunk pinned with holes accumulating until its refcount reaches
+ * zero, at which point the chunk is made available for allocations again.
+ *
+ * This requires a reference to the chunk be returned with every allocation.
+ * It may be possible to reduce the footprint of this by using a relative
+ * offset to the chunk start instead, but that would probably be more harmful
+ * to the alignment.
+ *
+ * This has some similarities to a slab allocator...
+ */
+
+#define CHUNK_ALIGNMENT 8192 /* XXX: this may be unnecessary, callers should be able to ideally size their chunkers */
+#define ALLOC_ALIGNMENT 8 /* allocations within the chunk need to be aligned since their size affects subsequent allocation offsets */
+#define ALIGN(_size, _alignment) (((_size) + _alignment - 1) & ~(_alignment - 1))
+
+typedef struct chunk_t {
+ chunker_t *chunker; /* chunker chunk belongs to */
+ list_head_t chunks; /* node on free/pinned list */
+ uint32_t n_refs; /* number of references (allocations) to this chunk */
+ unsigned next_offset; /* next available offset for allocation */
+ uint8_t mem[]; /* usable memory from this chunk */
+} chunk_t;
+
+typedef struct allocation_t {
+ chunk_t *chunk; /* chunk this allocation came from */
+ uint8_t mem[]; /* usable memory from this allocation */
+} allocation_t;
+
+struct chunker_t {
+ chunk_t *chunk; /* current chunk allocations come from */
+ unsigned chunk_size; /* size chunks are allocated in */
+ list_head_t free_chunks; /* list of completely free chunks */
+ list_head_t pinned_chunks; /* list of chunks pinned because they have an outstanding allocation */
+};
+
+
+/* Add a reference to a chunk. */
+static inline void chunk_ref(chunk_t *chunk)
+{
+ assert(chunk);
+ assert(chunk->chunker);
+
+ chunk->n_refs++;
+
+ assert(chunk->n_refs != 0);
+}
+
+
+/* Remove reference from a chunk, move to free list when no references remain. */
+static inline void chunk_unref(chunk_t *chunk)
+{
+ assert(chunk);
+ assert(chunk->chunker);
+ assert(chunk->n_refs > 0);
+
+ chunk->n_refs--;
+ if (chunk->n_refs == 0) {
+ list_move(&chunk->chunks, &chunk->chunker->free_chunks);
+ }
+}
+
+
+/* Return allocated size of the chunk */
+static inline unsigned chunk_alloc_size(chunker_t *chunker)
+{
+ assert(chunker);
+
+ return (sizeof(chunk_t) + chunker->chunk_size);
+}
+
+
+/* Get a new working chunk, retiring and replacing chunker->chunk. */
+static void chunker_new_chunk(chunker_t *chunker)
+{
+ chunk_t *chunk;
+
+ assert(chunker);
+
+ if (chunker->chunk) {
+ chunk_unref(chunker->chunk);
+ chunker->chunk = NULL;
+ }
+
+ if (!list_empty(&chunker->free_chunks)) {
+ chunk = list_entry(chunker->free_chunks.next, chunk_t, chunks);
+ list_del(&chunk->chunks);
+ } else {
+ /* No free chunks, must ask libc for memory */
+ chunk = malloc(chunk_alloc_size(chunker));
+ }
+
+ /* Note a chunk is pinned from the moment it's created, and a reference
+ * is added to represent chunker->chunk, even though no allocations
+ * occurred yet.
+ */
+ chunk->n_refs = 1;
+ chunk->next_offset = 0;
+ chunk->chunker = chunker;
+ chunker->chunk = chunk;
+ list_add(&chunk->chunks, &chunker->pinned_chunks);
+}
+
+
+/* Create a new chunker. */
+chunker_t * chunker_new(unsigned chunk_size)
+{
+ chunker_t *chunker;
+
+ chunker = calloc(1, sizeof(chunker_t));
+ if (!chunker) {
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&chunker->free_chunks);
+ INIT_LIST_HEAD(&chunker->pinned_chunks);
+
+ /* XXX: chunker->chunk_size does not include the size of the chunk_t container */
+ chunker->chunk_size = ALIGN(chunk_size, CHUNK_ALIGNMENT);
+
+ return chunker;
+}
+
+
+/* Allocate non-zeroed memory from a chunker. */
+void * chunker_alloc(chunker_t *chunker, unsigned size)
+{
+ allocation_t *allocation;
+
+ assert(chunker);
+ assert(size <= chunker->chunk_size);
+
+ size = ALIGN(sizeof(allocation_t) + size, ALLOC_ALIGNMENT);
+
+ if (!chunker->chunk || size + chunker->chunk->next_offset > chunker->chunk_size) {
+ /* Retire this chunk, time for a new one */
+ chunker_new_chunk(chunker);
+ }
+
+ if (!chunker->chunk) {
+ return NULL;
+ }
+
+ chunk_ref(chunker->chunk);
+ allocation = (allocation_t *)&chunker->chunk->mem[chunker->chunk->next_offset];
+ chunker->chunk->next_offset += size;
+ allocation->chunk = chunker->chunk;
+
+ assert(chunker->chunk->next_offset <= chunker->chunk_size);
+
+ return allocation->mem;
+}
+
+
+/* Free memory allocated from a chunker. */
+void chunker_free(void *ptr)
+{
+ allocation_t *allocation = container_of(ptr, allocation_t, mem);
+
+ assert(ptr);
+
+ chunk_unref(allocation->chunk);
+}
+
+
+/* Free a chunker and it's associated allocations. */
+void chunker_free_chunker(chunker_t *chunker)
+{
+ chunk_t *chunk, *_chunk;
+
+ assert(chunker);
+
+ if (chunker->chunk) {
+ chunk_unref(chunker->chunk);
+ }
+
+ assert(list_empty(&chunker->pinned_chunks));
+
+ list_for_each_entry_safe(chunk, _chunk, &chunker->free_chunks, chunks) {
+ free(chunk);
+ }
+
+ free(chunker);
+}
+
+/* TODO: add pinned chunk iterator interface for cache-friendly iterating across
+ * chunk contents.
+ * The idea is that at times when the performance is really important, the
+ * chunks will be full of active particles, because it's the large numbers
+ * which slows us down. At those times, it's beneficial to not walk linked
+ * lists of structs to process them, instead we just process all the elements
+ * of the chunk as an array and assume everything is active. The type of
+ * processing being done in this fashion is benign to perform on an unused
+ * element, as long as there's no dangling pointers being dereferenced. If
+ * there's references, a status field could be maintained in the entry to say
+ * if it's active, then simply skip processing of the inactive elements. This
+ * tends to be more cache-friendly than chasing pointers. A linked list
+ * heirarchy of particles is still maintained for the parent:child
+ * relationships under the assumption that some particles will make use of the
+ * tracked descendants, though nothing has been done with it yet.
+ *
+ * The current implementation of the _particle_t is variable length, which precludes
+ * this optimization. However, breaking out the particle_props_t into a separate
+ * chunker would allow running particles_age() across the props alone directly
+ * within the pinned chunks. The other passes are still done heirarchically,
+ * and require the full particle context.
+ */
diff --git a/src/modules/sparkler/chunker.h b/src/modules/sparkler/chunker.h
new file mode 100644
index 0000000..ac53cec
--- /dev/null
+++ b/src/modules/sparkler/chunker.h
@@ -0,0 +1,11 @@
+#ifndef _CHUNKER_H
+#define _CHUNKER_H
+
+typedef struct chunker_t chunker_t;
+
+chunker_t * chunker_new(unsigned chunk_size);
+void * chunker_alloc(chunker_t *chunker, unsigned size);
+void chunker_free(void *mem);
+void chunker_free_chunker(chunker_t *chunker);
+
+#endif
diff --git a/src/modules/sparkler/container.h b/src/modules/sparkler/container.h
new file mode 100644
index 0000000..a3779e8
--- /dev/null
+++ b/src/modules/sparkler/container.h
@@ -0,0 +1,11 @@
+#ifndef _CONTAINER_H
+#define _CONTAINER_H
+
+#include <stddef.h>
+
+#ifndef container_of
+#define container_of(_ptr, _type, _member) \
+ (_type *)((void *)(_ptr) - offsetof(_type, _member))
+#endif
+
+#endif
diff --git a/src/modules/sparkler/draw.h b/src/modules/sparkler/draw.h
new file mode 100644
index 0000000..5010374
--- /dev/null
+++ b/src/modules/sparkler/draw.h
@@ -0,0 +1,32 @@
+#ifndef _DRAW_H
+#define _DRAW_H
+
+#include <stdint.h>
+
+#include "fb.h"
+
+/* helper for scaling rgb colors and packing them into an pixel */
+static inline uint32_t makergb(uint32_t r, uint32_t g, uint32_t b, float intensity)
+{
+ r = (((float)intensity) * r);
+ g = (((float)intensity) * g);
+ b = (((float)intensity) * b);
+
+ return (((r & 0xff) << 16) | ((g & 0xff) << 8) | (b & 0xff));
+}
+
+static inline int draw_pixel(fb_fragment_t *f, int x, int y, uint32_t pixel)
+{
+ uint32_t *pixels = f->buf;
+
+ if (y < 0 || y >= f->height || x < 0 || x >= f->width) {
+ return 0;
+ }
+
+ /* FIXME this assumes stride is aligned to 4 */
+ pixels[(y * (f->width + (f->stride >> 2))) + x] = pixel;
+
+ return 1;
+}
+
+#endif
diff --git a/src/modules/sparkler/list.h b/src/modules/sparkler/list.h
new file mode 100644
index 0000000..48bca36
--- /dev/null
+++ b/src/modules/sparkler/list.h
@@ -0,0 +1,252 @@
+#ifndef __LIST_H
+#define __LIST_H
+
+/* linux kernel linked list interface */
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+typedef struct list_head {
+ struct list_head *next, *prev;
+} list_head_t;
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+ struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+ (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next)
+{
+ next->prev = new;
+ new->next = next;
+ new->prev = prev;
+ prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
+ */
+static inline void list_del(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ entry->next = (void *) 0;
+ entry->prev = (void *) 0;
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static inline void list_del_init(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_move - delete from one list and add as another's head
+ * @list: the entry to move
+ * @head: the head that will precede our entry
+ */
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+ __list_del(list->prev, list->next);
+ list_add(list, head);
+}
+
+/**
+ * list_move_tail - delete from one list and add as another's tail
+ * @list: the entry to move
+ * @head: the head that will follow our entry
+ */
+static inline void list_move_tail(struct list_head *list,
+ struct list_head *head)
+{
+ __list_del(list->prev, list->next);
+ list_add_tail(list, head);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static inline int list_empty(struct list_head *head)
+{
+ return head->next == head;
+}
+
+static inline void __list_splice(struct list_head *list,
+ struct list_head *head)
+{
+ struct list_head *first = list->next;
+ struct list_head *last = list->prev;
+ struct list_head *at = head->next;
+
+ first->prev = head;
+ head->next = first;
+
+ last->next = at;
+ at->prev = last;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(struct list_head *list, struct list_head *head)
+{
+ if (!list_empty(list))
+ __list_splice(list, head);
+}
+
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(struct list_head *list,
+ struct list_head *head)
+{
+ if (!list_empty(list)) {
+ __list_splice(list, head);
+ INIT_LIST_HEAD(list);
+ }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr: the &struct list_head pointer.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+ ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+/**
+ * list_for_each - iterate over a list
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each(pos, head) \
+ for (pos = (head)->next; pos != (head); \
+ pos = pos->next)
+/**
+ * list_for_each_prev - iterate over a list backwards
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+ for (pos = (head)->prev; pos != (head); \
+ pos = pos->prev)
+
+/**
+ * list_for_each_safe - iterate over a list safe against removal of list entry
+ * @pos: the &struct list_head to use as a loop counter.
+ * @n: another &struct list_head to use as temporary storage
+ * @head: the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+ for (pos = (head)->next, n = pos->next; pos != (head); \
+ pos = n, n = pos->next)
+
+/**
+ * list_for_each_entry - iterate over list of given type
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_prev - iterate over list of given type backwards
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_prev(pos, head, member) \
+ for (pos = list_entry((head)->prev, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.prev, typeof(*pos), member))
+
+
+/**
+ * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @pos: the type * to use as a loop counter.
+ * @n: another type * to use as temporary storage
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member), \
+ n = list_entry(pos->member.next, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
+
+#endif
diff --git a/src/modules/sparkler/particle.c b/src/modules/sparkler/particle.c
new file mode 100644
index 0000000..0e3d2c8
--- /dev/null
+++ b/src/modules/sparkler/particle.c
@@ -0,0 +1,14 @@
+#include "particle.h"
+
+/* convert a particle to a new type */
+void particle_convert(particles_t *particles, particle_t *p, particle_props_t *props, particle_ops_t *ops)
+{
+ particle_cleanup(particles, p);
+ if (props) {
+ *p->props = *props;
+ }
+ if (ops) {
+ p->ops = ops;
+ }
+ particle_init(particles, p);
+}
diff --git a/src/modules/sparkler/particle.h b/src/modules/sparkler/particle.h
new file mode 100644
index 0000000..95c117e
--- /dev/null
+++ b/src/modules/sparkler/particle.h
@@ -0,0 +1,79 @@
+#ifndef _PARTICLE_H
+#define _PARTICLE_H
+
+#include "bsp.h"
+#include "fb.h"
+#include "v3f.h"
+
+typedef struct particle_props_t {
+ v3f_t position; /* position in 3d space */
+ v3f_t direction; /* trajectory in 3d space */
+ float velocity; /* linear velocity */
+ float mass; /* mass of particle */
+ float drag; /* drag of particle */
+ int of_use:1; /* are these properties of use/meaningful? */
+} particle_props_t;
+
+typedef enum particle_status_t {
+ PARTICLE_ALIVE,
+ PARTICLE_DEAD
+} particle_status_t;
+
+typedef struct particle_t particle_t;
+typedef struct particles_t particles_t;
+
+typedef struct particle_ops_t {
+ unsigned context_size; /* size of the particle context (0 for none) */
+ int (*init)(particles_t *, particle_t *); /* initialize the particle, called after allocating context (optional) */
+ void (*cleanup)(particles_t *, particle_t *); /* cleanup function, called before freeing context (optional) */
+ particle_status_t (*sim)(particles_t *, particle_t *); /* simulate the particle for another cycle (required) */
+ void (*draw)(particles_t *, particle_t *, int, int, fb_fragment_t *); /* draw the particle, 3d->2d projection has been done already (optional) */
+} particle_ops_t;
+
+struct particle_t {
+ bsp_occupant_t occupant; /* occupant node in the bsp tree */
+ particle_props_t *props;
+ particle_ops_t *ops;
+ void *ctxt;
+};
+
+
+//#define rand_within_range(_min, _max) ((rand() % (_max - _min)) + _min)
+// the style of random number generator used by c libraries has less entropy in the lower bits meaning one shouldn't just use modulo, while this is slower, the results do seem a little different.
+#define rand_within_range(_min, _max) (int)(((float)_min) + ((float)rand() / (float)RAND_MAX) * (_max - _min))
+
+#define INHERIT_OPS NULL
+#define INHERIT_PROPS NULL
+
+
+static inline int particle_init(particles_t *particles, particle_t *p) {
+ if (p->ops->init) {
+ return p->ops->init(particles, p);
+ }
+
+ return 1;
+}
+
+
+static inline void particle_cleanup(particles_t *particles, particle_t *p) {
+ if (p->ops->cleanup) {
+ p->ops->cleanup(particles, p);
+ }
+}
+
+
+static inline particle_status_t particle_sim(particles_t *particles, particle_t *p) {
+ return p->ops->sim(particles, p);
+}
+
+
+static inline void particle_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f) {
+ if (p->ops->draw) {
+ p->ops->draw(particles, p, x, y, f);
+ }
+}
+
+
+void particle_convert(particles_t *particles, particle_t *p, particle_props_t *props, particle_ops_t *ops);
+
+#endif
diff --git a/src/modules/sparkler/particles.c b/src/modules/sparkler/particles.c
new file mode 100644
index 0000000..0eb260e
--- /dev/null
+++ b/src/modules/sparkler/particles.c
@@ -0,0 +1,342 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <math.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "fb.h"
+
+#include "chunker.h"
+#include "container.h"
+#include "bsp.h"
+#include "list.h"
+#include "particle.h"
+#include "particles.h"
+#include "v3f.h"
+
+#define ZCONST 0.4f
+
+/* private particle with all the particles bookkeeping... */
+typedef struct _particle_t {
+ list_head_t siblings; /* sibling particles */
+ list_head_t children; /* children particles */
+
+ particle_props_t props; /* we reference this in the public particle, I might change
+ * the way props are allocated so coding everything to use a
+ * reference for now. It may make sense to have props allocated
+ * separately via their own chunker, and perform some mass operations
+ * against the list of chunks rather than chasing the pointers of
+ * the particle heirarchy. TODO
+ */
+ particle_t public; /* the public particle_t is embedded */
+
+ uint8_t context[]; /* particle type-specific context [public.ops.context_size] */
+} _particle_t;
+
+struct particles_t {
+ chunker_t *chunker; /* chunker for variably-sized particle allocation (includes context) */
+ list_head_t active; /* top-level active list of particles heirarchy */
+ bsp_t *bsp; /* bsp spatial index of the particles */
+};
+
+
+/* create a new particle system */
+particles_t * particles_new(void)
+{
+ particles_t *particles;
+
+ particles = calloc(1, sizeof(particles_t));
+ if (!particles) {
+ return NULL;
+ }
+
+ particles->chunker = chunker_new(sizeof(_particle_t) * 128);
+ if (!particles->chunker) {
+ return NULL;
+ }
+
+ particles->bsp = bsp_new();
+ if (!particles->bsp) {
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&particles->active);
+
+ return particles;
+}
+
+
+/* TODO: add a public interface for destroying particles? for now we just return PARTICLE_DEAD in the sim */
+static inline void _particles_free_particle(particles_t *particles, _particle_t *p)
+{
+ assert(p);
+
+ particle_cleanup(particles, &p->public);
+ chunker_free(p);
+}
+
+
+static inline void _particles_free(particles_t *particles, list_head_t *list)
+{
+ _particle_t *p, *_p;
+
+ assert(particles);
+ assert(list);
+
+ list_for_each_entry_safe(p, _p, list, siblings) {
+ _particles_free(particles, &p->children);
+ _particles_free_particle(particles, p);
+ }
+}
+
+
+/* free up all the particles */
+void particles_free(particles_t *particles)
+{
+ assert(particles);
+
+ _particles_free(particles, &particles->active);
+}
+
+
+/* reclaim a dead particle, moving it to the free list */
+static void particles_reap_particle(particles_t *particles, _particle_t *particle)
+{
+ assert(particles);
+ assert(particle);
+
+ if (!list_empty(&particle->children)) {
+ /* adopt any orphaned children using the global parts list */
+ list_splice(&particle->children, &particles->active);
+ }
+
+ list_del(&particle->siblings);
+ bsp_delete_occupant(particles->bsp, &particle->public.occupant);
+ _particles_free_particle(particles, particle);
+}
+
+
+/* add a particle to the specified list */
+static inline int _particles_add_particle(particles_t *particles, list_head_t *list, particle_props_t *props, particle_ops_t *ops)
+{
+ _particle_t *p;
+
+ assert(particles);
+ assert(ops);
+ assert(list);
+
+ p = chunker_alloc(particles->chunker, sizeof(_particle_t) + ops->context_size);
+ if (!p) {
+ return 0;
+ }
+
+ INIT_LIST_HEAD(&p->children);
+ INIT_LIST_HEAD(&p->siblings);
+
+ /* inherit the parent's properties and ops if they're not explicitly provided */
+ if (props) {
+ p->props = *props;
+ } else {
+ p->props.of_use = 0;
+ }
+
+ p->public.props = &p->props;
+ p->public.ops = ops;
+
+ if (ops->context_size) {
+ p->public.ctxt = p->context;
+ }
+
+ if (!particle_init(particles, &p->public)) {
+ /* XXX FIXME this shouldn't be normal, we don't want to allocate
+ * particles that cannot be initialized. the rockets today set a cap
+ * by failing initialization, that's silly. */
+ chunker_free(p);
+ return 0;
+ }
+
+ p->public.props->of_use = 1;
+ list_add(&p->siblings, list);
+ bsp_add_occupant(particles->bsp, &p->public.occupant, &p->props.position);
+
+ return 1;
+}
+
+
+/* add a new "top-level" particle of the specified props and ops taking from the provided parts list */
+int particles_add_particle(particles_t *particles, particle_props_t *props, particle_ops_t *ops)
+{
+ assert(particles);
+
+ return _particles_add_particle(particles, &particles->active, props, ops);
+}
+
+
+/* spawn a new child particle from a parent, initializing it via inheritance if desired */
+void particles_spawn_particle(particles_t *particles, particle_t *parent, particle_props_t *props, particle_ops_t *ops)
+{
+ _particle_t *p = container_of(parent, _particle_t, public);
+
+ assert(particles);
+ assert(parent);
+
+ _particles_add_particle(particles, &p->children, props ? props : parent->props, ops ? ops : parent->ops);
+}
+
+
+/* plural version of particle_add(); adds multiple "top-level" particles of uniform props and ops */
+void particles_add_particles(particles_t *particles, particle_props_t *props, particle_ops_t *ops, int num)
+{
+ int i;
+
+ assert(particles);
+
+ for (i = 0; i < num; i++) {
+ _particles_add_particle(particles, &particles->active, props, ops);
+ }
+}
+
+
+/* Simple accessor to get the bsp pointer, the bsp is special because we don't want to do
+ * callbacks per-occupant, so the bsp_occupant_t and search functions are used directly by
+ * the per-particle code needing nearest-neighbor search. that requires an accessor since
+ * particles_t is opaque. This seemed less shitty than opening up particles_t.
+ */
+bsp_t * particles_bsp(particles_t *particles)
+{
+ assert(particles);
+ assert(particles->bsp);
+
+ return particles->bsp;
+}
+
+
+static inline void _particles_draw(particles_t *particles, list_head_t *list, fb_fragment_t *fragment)
+{
+ float w2 = fragment->width * .5f, h2 = fragment->height * .5f;
+ _particle_t *p;
+
+ assert(particles);
+ assert(list);
+ assert(fragment);
+
+ list_for_each_entry(p, list, siblings) {
+ int x, y;
+
+ /* project the 3d coordinates onto the 2d plane */
+ x = (p->props.position.x / (p->props.position.z - ZCONST) * w2) + w2;
+ y = (p->props.position.y / (p->props.position.z - ZCONST) * h2) + h2;
+
+ particle_draw(particles, &p->public, x, y, fragment);
+
+ if (!list_empty(&p->children)) {
+ _particles_draw(particles, &p->children, fragment);
+ }
+ }
+}
+
+
+/* draw all of the particles, currently called in heirarchical order */
+void particles_draw(particles_t *particles, fb_fragment_t *fragment)
+{
+ assert(particles);
+
+ _particles_draw(particles, &particles->active, fragment);
+}
+
+
+static inline particle_status_t _particles_sim(particles_t *particles, list_head_t *list)
+{
+ particle_status_t ret = PARTICLE_DEAD, s;
+ _particle_t *p, *_p;
+
+ assert(particles);
+ assert(list);
+
+ list_for_each_entry_safe(p, _p, list, siblings) {
+ if ((s = particle_sim(particles, &p->public)) == PARTICLE_ALIVE) {
+ ret = PARTICLE_ALIVE;
+
+ if (!list_empty(&p->children) &&
+ _particles_sim(particles, &p->children) == PARTICLE_ALIVE) {
+ ret = PARTICLE_ALIVE;
+ }
+ } else {
+ particles_reap_particle(particles, p);
+ }
+ }
+
+ return ret;
+}
+
+
+/* simulate the particles, call the sim method of every particle in the heirarchy, this is what makes the particles dynamic */
+/* if any paticle is still living, we return PARTICLE_ALIVE, to inform the caller when everything's dead */
+particle_status_t particles_sim(particles_t *particles)
+{
+ assert(particles);
+
+ return _particles_sim(particles, &particles->active);
+}
+
+
+static inline void _particles_age(particles_t *particles, list_head_t *list)
+{
+ _particle_t *p;
+
+ assert(particles);
+ assert(list);
+
+ /* TODO: since this *only* involves the properties struct, if they were
+ * allocated from a separate slab containing only properties, it'd be
+ * more efficient to iterate across property arrays and skip inactive
+ * entries. This heirarchical pointer-chasing recursion isn't
+ * particularly good for cache utilization.
+ */
+ list_for_each_entry(p, list, siblings) {
+#if 1
+ if (p->props.mass > 0.0f) {
+ /* gravity, TODO: mass isn't applied. */
+ static v3f_t gravity = v3f_init(0.0f, -0.05f, 0.0f);
+
+ p->props.direction = v3f_add(&p->props.direction, &gravity);
+ p->props.direction = v3f_normalize(&p->props.direction);
+ }
+#endif
+
+#if 1
+ /* some drag/resistance proportional to velocity TODO: integrate mass */
+ if (p->props.velocity > 0.0f) {
+ p->props.velocity -= ((p->props.velocity * p->props.velocity * p->props.drag));
+ if (p->props.velocity < 0.0f) {
+ p->props.velocity = 0;
+ }
+ }
+#endif
+
+ /* regular movement */
+ if (p->props.velocity > 0.0f) {
+ v3f_t movement = v3f_mult_scalar(&p->props.direction, p->props.velocity);
+
+ p->props.position = v3f_add(&p->props.position, &movement);
+ bsp_move_occupant(particles->bsp, &p->public.occupant, &p->props.position);
+ }
+
+ if (!list_empty(&p->children)) {
+ _particles_age(particles, &p->children);
+ }
+ }
+}
+
+
+/* advance time for all the particles (move them), this doesn't currently invoke any part-specific helpers, it's just applying
+ * physics-type stuff, moving particles according to their velocities, directions, mass, drag, gravity etc... */
+void particles_age(particles_t *particles)
+{
+ assert(particles);
+
+ _particles_age(particles, &particles->active);
+}
diff --git a/src/modules/sparkler/particles.h b/src/modules/sparkler/particles.h
new file mode 100644
index 0000000..689934b
--- /dev/null
+++ b/src/modules/sparkler/particles.h
@@ -0,0 +1,21 @@
+#ifndef _PARTICLES_H
+#define _PARTICLES_H
+
+#include "bsp.h"
+#include "fb.h"
+#include "list.h"
+#include "particle.h"
+
+typedef struct particles_t particles_t;
+
+particles_t * particles_new(void);
+void particles_draw(particles_t *particles, fb_fragment_t *fragment);
+particle_status_t particles_sim(particles_t *particles);
+void particles_age(particles_t *particles);
+void particles_free(particles_t *particles);
+int particles_add_particle(particles_t *particles, particle_props_t *props, particle_ops_t *ops);
+void particles_spawn_particle(particles_t *particles, particle_t *parent, particle_props_t *props, particle_ops_t *ops);
+void particles_add_particles(particles_t *particles, particle_props_t *props, particle_ops_t *ops, int num);
+bsp_t * particles_bsp(particles_t *particles);
+
+#endif
diff --git a/src/modules/sparkler/rocket.c b/src/modules/sparkler/rocket.c
new file mode 100644
index 0000000..6b9dc5e
--- /dev/null
+++ b/src/modules/sparkler/rocket.c
@@ -0,0 +1,144 @@
+#include <stdlib.h>
+
+#include "draw.h"
+#include "particle.h"
+#include "particles.h"
+
+/* a "rocket" particle type */
+#define ROCKET_MAX_DECAY_RATE 20
+#define ROCKET_MIN_DECAY_RATE 2
+#define ROCKET_MAX_LIFETIME 500
+#define ROCKET_MIN_LIFETIME 300
+#define ROCKETS_MAX 20
+#define ROCKETS_XPLODE_MIN_SIZE 2000
+#define ROCKETS_XPLODE_MAX_SIZE 8000
+
+extern particle_ops_t burst_ops;
+extern particle_ops_t spark_ops;
+extern particle_ops_t xplode_ops;
+
+static unsigned rockets_cnt;
+
+typedef struct rocket_ctxt_t {
+ int decay_rate;
+ int longevity;
+ v3f_t wander;
+ float last_velocity; /* cache velocity to sense violent accelerations and explode when they happen */
+} rocket_ctxt_t;
+
+
+static int rocket_init(particles_t *particles, particle_t *p)
+{
+ rocket_ctxt_t *ctxt = p->ctxt;
+
+ if (rockets_cnt >= ROCKETS_MAX) {
+ return 0;
+ }
+ rockets_cnt++;
+
+ ctxt->decay_rate = rand_within_range(ROCKET_MIN_DECAY_RATE, ROCKET_MAX_DECAY_RATE);
+ ctxt->longevity = rand_within_range(ROCKET_MIN_LIFETIME, ROCKET_MAX_LIFETIME);
+
+ ctxt->wander.x = (float)(rand_within_range(0, 628) - 314) / 10000.0f;
+ ctxt->wander.y = (float)(rand_within_range(0, 628) - 314) / 10000.0f;
+ ctxt->wander.z = (float)(rand_within_range(0, 628) - 314) / 10000.0f;
+ ctxt->wander = v3f_normalize(&ctxt->wander);
+
+ ctxt->last_velocity = p->props->velocity;
+ p->props->drag = 0.4;
+ p->props->mass = 0.8;
+
+ return 1;
+}
+
+
+static particle_status_t rocket_sim(particles_t *particles, particle_t *p)
+{
+ rocket_ctxt_t *ctxt = p->ctxt;
+ int i, n_sparks;
+
+ if (!ctxt->longevity ||
+ (ctxt->longevity -= ctxt->decay_rate) <= 0 ||
+ p->props->velocity - ctxt->last_velocity > p->props->velocity * .05) { /* explode if accelerated too hard (burst) */
+ int n_xplode;
+ /* on death we explode */
+
+ ctxt->longevity = 0;
+
+ /* add a burst shockwave particle at our location
+ * TODO: need way to supply particle-type-specific parameters at spawn (burst size should derive from n_xplode)
+ */
+ particles_spawn_particle(particles, p, NULL, &burst_ops);
+
+ /* add a bunch of new explosion particles */
+ /* TODO: also particle-type-specific parameters, colors! rocket bursts should be able to vary the color. */
+ n_xplode = rand_within_range(ROCKETS_XPLODE_MIN_SIZE, ROCKETS_XPLODE_MAX_SIZE);
+ for (i = 0; i < n_xplode; i++) {
+ particle_props_t props = *p->props;
+ particle_ops_t *ops = &xplode_ops;
+
+ props.direction.x = ((float)(rand_within_range(0, 314159 * 2) - 314159) / 100000.0);
+ props.direction.y = ((float)(rand_within_range(0, 314159 * 2) - 314159) / 100000.0);
+ props.direction.z = ((float)(rand_within_range(0, 314159 * 2) - 314159) / 100000.0);
+ props.direction = v3f_normalize(&props.direction);
+
+ //props->velocity = ((float)rand_within_range(100, 200) / 100000.0);
+ props.velocity = ((float)rand_within_range(100, 300) / 100000.0);
+ particles_spawn_particle(particles, p, &props, ops);
+ }
+ return PARTICLE_DEAD;
+ }
+
+#if 1
+ /* FIXME: this isn't behaving as intended */
+ p->props->direction = v3f_add(&p->props->direction, &ctxt->wander);
+ p->props->direction = v3f_normalize(&p->props->direction);
+#endif
+ p->props->velocity += .00003;
+
+ /* spray some sparks behind the rocket */
+ n_sparks = rand_within_range(10, 40);
+ for (i = 0; i < n_sparks; i++) {
+ particle_props_t props = *p->props;
+
+ props.direction = v3f_negate(&props.direction);
+
+ props.direction.x += (float)(rand_within_range(0, 40) - 20) / 100.0;
+ props.direction.y += (float)(rand_within_range(0, 40) - 20) / 100.0;
+ props.direction.z += (float)(rand_within_range(0, 40) - 20) / 100.0;
+ props.direction = v3f_normalize(&props.direction);
+
+ props.velocity = (float)rand_within_range(10, 50) / 100000.0;
+ particles_spawn_particle(particles, p, &props, &spark_ops);
+ }
+
+ ctxt->last_velocity = p->props->velocity;
+
+ return PARTICLE_ALIVE;
+}
+
+
+static void rocket_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
+{
+ rocket_ctxt_t *ctxt = p->ctxt;
+
+ if (!draw_pixel(f, x, y, 0xff0000)) {
+ /* kill off parts that wander off screen */
+ ctxt->longevity = 0;
+ }
+}
+
+
+static void rocket_cleanup(particles_t *particles, particle_t *p)
+{
+ rockets_cnt--;
+}
+
+
+particle_ops_t rocket_ops = {
+ .context_size = sizeof(rocket_ctxt_t),
+ .sim = rocket_sim,
+ .init = rocket_init,
+ .draw = rocket_draw,
+ .cleanup = rocket_cleanup,
+ };
diff --git a/src/modules/sparkler/simple.c b/src/modules/sparkler/simple.c
new file mode 100644
index 0000000..e453e46
--- /dev/null
+++ b/src/modules/sparkler/simple.c
@@ -0,0 +1,113 @@
+#include <stdlib.h>
+
+#include "draw.h"
+#include "particle.h"
+#include "particles.h"
+
+
+/* a "simple" particle type */
+#define SIMPLE_MAX_DECAY_RATE 20
+#define SIMPLE_MIN_DECAY_RATE 2
+#define SIMPLE_MAX_LIFETIME 110
+#define SIMPLE_MIN_LIFETIME 30
+#define SIMPLE_MAX_SPAWN 15
+#define SIMPLE_MIN_SPAWN 2
+
+extern particle_ops_t rocket_ops;
+
+typedef struct _simple_ctxt_t {
+ int decay_rate;
+ int longevity;
+ int lifetime;
+} simple_ctxt_t;
+
+
+static int simple_init(particles_t *particles, particle_t *p)
+{
+ simple_ctxt_t *ctxt = p->ctxt;
+
+ ctxt->decay_rate = rand_within_range(SIMPLE_MIN_DECAY_RATE, SIMPLE_MAX_DECAY_RATE);
+ ctxt->lifetime = ctxt->longevity = rand_within_range(SIMPLE_MIN_LIFETIME, SIMPLE_MAX_LIFETIME);
+
+ if (!p->props->of_use) {
+ /* everything starts from the bottom center */
+ p->props->position.x = 0;
+ p->props->position.y = 0;
+ p->props->position.z = 0;
+
+ /* TODO: direction random-ish within the range of a narrow upward facing cone */
+ p->props->direction.x = (float)(rand_within_range(0, 6) - 3) * .1f;
+ p->props->direction.y = 1.0f + (float)(rand_within_range(0, 6) - 3) * .1f;
+ p->props->direction.z = (float)(rand_within_range(0, 6) - 3) * .1f;
+ p->props->direction = v3f_normalize(&p->props->direction);
+
+ p->props->velocity = (float)rand_within_range(300, 800) / 100000.0;
+
+ p->props->drag = 0.03;
+ p->props->mass = 0.3;
+ p->props->of_use = 1;
+ } /* else { we've been given properties, manipulate them or run with them? } */
+
+ return 1;
+}
+
+
+static particle_status_t simple_sim(particles_t *particles, particle_t *p)
+{
+ simple_ctxt_t *ctxt = p->ctxt;
+
+ /* a particle is free to manipulate its children list when aging, but not itself or its siblings */
+ /* return PARTICLE_DEAD to remove kill yourself, do not age children here, the age pass will recurse
+ * into children and age them independently _after_ their parents have been aged
+ */
+ if (!ctxt->longevity || (ctxt->longevity -= ctxt->decay_rate) <= 0) {
+ ctxt->longevity = 0;
+ return PARTICLE_DEAD;
+ }
+
+ /* create particles inheriting our type based on some silly conditions, with some tweaks to their direction */
+ if (ctxt->longevity == 42 || (ctxt->longevity > 500 && !(ctxt->longevity % 50))) {
+ int i, num = rand_within_range(SIMPLE_MIN_SPAWN, SIMPLE_MAX_SPAWN);
+
+ for (i = 0; i < num; i++) {
+ particle_props_t props = *p->props;
+ particle_ops_t *ops = INHERIT_OPS;
+
+ if (i == (SIMPLE_MAX_SPAWN - 2)) {
+ ops = &rocket_ops;
+ props.velocity = (float)rand_within_range(60, 100) / 1000000.0;
+ } else {
+ props.velocity = (float)rand_within_range(30, 100) / 10000.0;
+ }
+
+ props.direction.x += (float)(rand_within_range(0, 315 * 2) - 315) / 100.0;
+ props.direction.y += (float)(rand_within_range(0, 315 * 2) - 315) / 100.0;
+ props.direction.z += (float)(rand_within_range(0, 315 * 2) - 315) / 100.0;
+ props.direction = v3f_normalize(&props.direction);
+
+ particles_spawn_particle(particles, p, &props, ops); // XXX
+ }
+ }
+
+ return PARTICLE_ALIVE;
+}
+
+
+static void simple_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
+{
+ simple_ctxt_t *ctxt = p->ctxt;
+
+ if (!draw_pixel(f, x, y, makergb(0xff, 0xff, 0xff, ((float)ctxt->longevity / ctxt->lifetime)))) {
+ /* immediately kill off stars that wander off screen */
+ ctxt->longevity = 0;
+ }
+}
+
+
+particle_ops_t simple_ops = {
+ .context_size = sizeof(simple_ctxt_t),
+ .sim = simple_sim,
+ .init = simple_init,
+ .draw = simple_draw,
+ .cleanup = NULL,
+ };
diff --git a/src/modules/sparkler/spark.c b/src/modules/sparkler/spark.c
new file mode 100644
index 0000000..ea68ac2
--- /dev/null
+++ b/src/modules/sparkler/spark.c
@@ -0,0 +1,63 @@
+#include <stdlib.h>
+
+#include "draw.h"
+#include "particle.h"
+#include "particles.h"
+
+/* a "spark" particle type, emitted from behind rockets */
+#define SPARK_MAX_DECAY_RATE 20
+#define SPARK_MIN_DECAY_RATE 2
+#define SPARK_MAX_LIFETIME 150
+#define SPARK_MIN_LIFETIME 1
+
+typedef struct _spark_ctxt_t {
+ int decay_rate;
+ int longevity;
+ int lifetime;
+} spark_ctxt_t;
+
+
+static int spark_init(particles_t *particles, particle_t *p)
+{
+ spark_ctxt_t *ctxt = p->ctxt;
+
+ p->props->drag = 20.0;
+ p->props->mass = 0.1;
+ ctxt->decay_rate = rand_within_range(SPARK_MIN_DECAY_RATE, SPARK_MAX_DECAY_RATE);
+ ctxt->lifetime = ctxt->longevity = rand_within_range(SPARK_MIN_LIFETIME, SPARK_MAX_LIFETIME);
+
+ return 1;
+}
+
+
+static particle_status_t spark_sim(particles_t *particles, particle_t *p)
+{
+ spark_ctxt_t *ctxt = p->ctxt;
+
+ if (!ctxt->longevity || (ctxt->longevity -= ctxt->decay_rate) <= 0) {
+ ctxt->longevity = 0;
+ return PARTICLE_DEAD;
+ }
+
+ return PARTICLE_ALIVE;
+}
+
+
+static void spark_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
+{
+ spark_ctxt_t *ctxt = p->ctxt;
+
+ if (!draw_pixel(f, x, y, makergb(0xff, 0xa0, 0x20, ((float)ctxt->longevity / ctxt->lifetime)))) {
+ /* offscreen */
+ ctxt->longevity = 0;
+ }
+}
+
+
+particle_ops_t spark_ops = {
+ .context_size = sizeof(spark_ctxt_t),
+ .sim = spark_sim,
+ .init = spark_init,
+ .draw = spark_draw,
+ .cleanup = NULL,
+ };
diff --git a/src/modules/sparkler/sparkler.c b/src/modules/sparkler/sparkler.c
new file mode 100644
index 0000000..0bb0fcf
--- /dev/null
+++ b/src/modules/sparkler/sparkler.c
@@ -0,0 +1,53 @@
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "fb.h"
+#include "rototiller.h"
+#include "util.h"
+
+#include "particles.h"
+
+/* particle system gadget (C) Vito Caputo <vcaputo@pengaru.com> 2/15/2014 */
+/* 1/10/2015 added octree bsp (though not yet leveraged) */
+/* 11/25/2016 refactor and begun adapting to rototiller */
+
+#define INIT_PARTS 100
+
+extern particle_ops_t simple_ops;
+
+
+/* Render a 3D particle system */
+static void sparkler(fb_fragment_t *fragment)
+{
+ static particles_t *particles;
+ static int initialized;
+ uint32_t *buf = fragment->buf;
+
+ if (!initialized) {
+ srand(time(NULL) + getpid());
+
+ particles = particles_new();
+ particles_add_particles(particles, NULL, &simple_ops, INIT_PARTS);
+
+ initialized = 1;
+ }
+
+ memset(buf, 0, ((fragment->width << 2) + fragment->stride) * fragment->height);
+
+ particles_age(particles);
+ particles_draw(particles, fragment);
+ particles_sim(particles);
+ particles_add_particles(particles, NULL, &simple_ops, INIT_PARTS / 4);
+}
+
+
+rototiller_renderer_t sparkler_renderer = {
+ .render = sparkler,
+ .name = "sparkler",
+ .description = "Particle system with spatial interactions",
+ .author = "Vito Caputo <vcaputo@pengaru.com>",
+ .license = "GPLv2",
+};
diff --git a/src/modules/sparkler/sparkler.h b/src/modules/sparkler/sparkler.h
new file mode 100644
index 0000000..3beb610
--- /dev/null
+++ b/src/modules/sparkler/sparkler.h
@@ -0,0 +1,8 @@
+#ifndef _SPARKLER_H
+#define _SPARKLER_H
+
+#include "fb.h"
+
+void sparkler(fb_fragment_t *fragment);
+
+#endif
diff --git a/src/modules/sparkler/v3f.h b/src/modules/sparkler/v3f.h
new file mode 100644
index 0000000..8bf7e24
--- /dev/null
+++ b/src/modules/sparkler/v3f.h
@@ -0,0 +1,157 @@
+#ifndef _V3F_H
+#define _V3F_H
+
+#include <math.h>
+
+typedef struct v3f_t {
+ float x, y, z;
+} v3f_t;
+
+#define v3f_set(_v3f, _x, _y, _z) \
+ (_v3f)->x = _x; \
+ (_v3f)->y = _y; \
+ (_v3f)->z = _z;
+
+#define v3f_init(_x, _y, _z) \
+ { \
+ .x = _x, \
+ .y = _y, \
+ .z = _z, \
+ }
+
+/* return if a and b are equal */
+static inline int v3f_equal(v3f_t *a, v3f_t *b)
+{
+ return (a->x == b->x && a->y == b->y && a->z == b->z);
+}
+
+
+/* return the result of (a + b) */
+static inline v3f_t v3f_add(v3f_t *a, v3f_t *b)
+{
+ v3f_t res = v3f_init(a->x + b->x, a->y + b->y, a->z + b->z);
+
+ return res;
+}
+
+
+/* return the result of (a - b) */
+static inline v3f_t v3f_sub(v3f_t *a, v3f_t *b)
+{
+ v3f_t res = v3f_init(a->x - b->x, a->y - b->y, a->z - b->z);
+
+ return res;
+}
+
+
+/* return the result of (-v) */
+static inline v3f_t v3f_negate(v3f_t *v)
+{
+ v3f_t res = v3f_init(-v->x, -v->y, -v->z);
+
+ return res;
+}
+
+
+/* return the result of (a * b) */
+static inline v3f_t v3f_mult(v3f_t *a, v3f_t *b)
+{
+ v3f_t res = v3f_init(a->x * b->x, a->y * b->y, a->z * b->z);
+
+ return res;
+}
+
+
+/* return the result of (v * scalar) */
+static inline v3f_t v3f_mult_scalar(v3f_t *v, float scalar)
+{
+ v3f_t res = v3f_init( v->x * scalar, v->y * scalar, v->z * scalar);
+
+ return res;
+}
+
+
+/* return the result of (uv / scalar) */
+static inline v3f_t v3f_div_scalar(v3f_t *v, float scalar)
+{
+ v3f_t res = v3f_init(v->x / scalar, v->y / scalar, v->z / scalar);
+
+ return res;
+}
+
+
+/* return the result of (a . b) */
+static inline float v3f_dot(v3f_t *a, v3f_t *b)
+{
+ return a->x * b->x + a->y * b->y + a->z * b->z;
+}
+
+
+/* return the length of the supplied vector */
+static inline float v3f_length(v3f_t *v)
+{
+ return sqrtf(v3f_dot(v, v));
+}
+
+
+/* return the normalized form of the supplied vector */
+static inline v3f_t v3f_normalize(v3f_t *v)
+{
+ v3f_t nv;
+ float f;
+
+ f = 1.0f / v3f_length(v);
+
+ v3f_set(&nv, f * v->x, f * v->y, f * v->z);
+
+ return nv;
+}
+
+
+/* return the distance squared between two arbitrary points */
+static inline float v3f_distance_sq(v3f_t *a, v3f_t *b)
+{
+ return powf(a->x - b->x, 2) + powf(a->y - b->y, 2) + powf(a->z - b->z, 2);
+}
+
+
+/* return the distance between two arbitrary points */
+/* (consider using v3f_distance_sq() instead if possible, sqrtf() is slow) */
+static inline float v3f_distance(v3f_t *a, v3f_t *b)
+{
+ return sqrtf(v3f_distance_sq(a, b));
+}
+
+
+/* return the cross product of two unit vectors */
+static inline v3f_t v3f_cross(v3f_t *a, v3f_t *b)
+{
+ v3f_t product = v3f_init(a->y * b->z - a->z * b->y, a->z * b->x - a->x * b->z, a->x * b->y - a->y * b->x);
+
+ return product;
+}
+
+
+/* return the linearly interpolated vector between the two vectors at point alpha (0-1.0) */
+static inline v3f_t v3f_lerp(v3f_t *a, v3f_t *b, float alpha)
+{
+ v3f_t lerp_a, lerp_b;
+
+ lerp_a = v3f_mult_scalar(a, 1.0f - alpha);
+ lerp_b = v3f_mult_scalar(b, alpha);
+
+ return v3f_add(&lerp_a, &lerp_b);
+}
+
+
+/* return the normalized linearly interpolated vector between the two vectors at point alpha (0-1.0) */
+static inline v3f_t v3f_nlerp(v3f_t *a, v3f_t *b, float alpha)
+{
+ v3f_t lerp;
+
+ lerp = v3f_lerp(a, b, alpha);
+
+ return v3f_normalize(&lerp);
+}
+
+#endif
diff --git a/src/modules/sparkler/xplode.c b/src/modules/sparkler/xplode.c
new file mode 100644
index 0000000..24a436e
--- /dev/null
+++ b/src/modules/sparkler/xplode.c
@@ -0,0 +1,82 @@
+#include <stdlib.h>
+
+#include "draw.h"
+#include "particle.h"
+#include "particles.h"
+
+/* a "xplode" particle type, emitted by rockets in large numbers at the end of their lifetime */
+#define XPLODE_MAX_DECAY_RATE 10
+#define XPLODE_MIN_DECAY_RATE 5
+#define XPLODE_MAX_LIFETIME 150
+#define XPLODE_MIN_LIFETIME 5
+
+extern particle_ops_t spark_ops;
+particle_ops_t xplode_ops;
+
+typedef struct _xplode_ctxt_t {
+ int decay_rate;
+ int longevity;
+ int lifetime;
+} xplode_ctxt_t;
+
+
+static int xplode_init(particles_t *particles, particle_t *p)
+{
+ xplode_ctxt_t *ctxt = p->ctxt;
+
+ ctxt->decay_rate = rand_within_range(XPLODE_MIN_DECAY_RATE, XPLODE_MAX_DECAY_RATE);
+ ctxt->lifetime = ctxt->longevity = rand_within_range(XPLODE_MIN_LIFETIME, XPLODE_MAX_LIFETIME);
+
+ p->props->drag = 10.9;
+ p->props->mass = 0.3;
+
+ return 1;
+}
+
+
+static particle_status_t xplode_sim(particles_t *particles, particle_t *p)
+{
+ xplode_ctxt_t *ctxt = p->ctxt;
+
+ if (!ctxt->longevity || (ctxt->longevity -= ctxt->decay_rate) <= 0) {
+ ctxt->longevity = 0;
+ return PARTICLE_DEAD;
+ }
+
+ /* litter some small sparks behind the explosion particle */
+ if (!(ctxt->lifetime % 30)) {
+ particle_props_t props = *p->props;
+
+ props.velocity = (float)rand_within_range(10, 50) / 10000.0;
+ particles_spawn_particle(particles, p, &props, &xplode_ops);
+ }
+
+ return PARTICLE_ALIVE;
+}
+
+
+static void xplode_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
+{
+ xplode_ctxt_t *ctxt = p->ctxt;
+ uint32_t color;
+
+ if (ctxt->longevity == ctxt->lifetime) {
+ color = makergb(0xff, 0xff, 0xa0, 1.0);
+ } else {
+ color = makergb(0xff, 0xff, 0x00, ((float)ctxt->longevity / ctxt->lifetime));
+ }
+
+ if (!draw_pixel(f, x, y, color)) {
+ /* offscreen */
+ ctxt->longevity = 0;
+ }
+}
+
+
+particle_ops_t xplode_ops = {
+ .context_size = sizeof(xplode_ctxt_t),
+ .sim = xplode_sim,
+ .init = xplode_init,
+ .draw = xplode_draw,
+ .cleanup = NULL,
+ };
diff --git a/src/modules/stars/Makefile.am b/src/modules/stars/Makefile.am
new file mode 100644
index 0000000..e709e85
--- /dev/null
+++ b/src/modules/stars/Makefile.am
@@ -0,0 +1,4 @@
+noinst_LIBRARIES = libstars.a
+libstars_a_SOURCES = draw.h stars.c stars.h starslib.c starslib.h
+libstars_a_CFLAGS = @ROTOTILLER_CFLAGS@
+libstars_a_CPPFLAGS = @ROTOTILLER_CFLAGS@ -I../../
diff --git a/src/modules/stars/draw.h b/src/modules/stars/draw.h
new file mode 100644
index 0000000..5010374
--- /dev/null
+++ b/src/modules/stars/draw.h
@@ -0,0 +1,32 @@
+#ifndef _DRAW_H
+#define _DRAW_H
+
+#include <stdint.h>
+
+#include "fb.h"
+
+/* helper for scaling rgb colors and packing them into an pixel */
+static inline uint32_t makergb(uint32_t r, uint32_t g, uint32_t b, float intensity)
+{
+ r = (((float)intensity) * r);
+ g = (((float)intensity) * g);
+ b = (((float)intensity) * b);
+
+ return (((r & 0xff) << 16) | ((g & 0xff) << 8) | (b & 0xff));
+}
+
+static inline int draw_pixel(fb_fragment_t *f, int x, int y, uint32_t pixel)
+{
+ uint32_t *pixels = f->buf;
+
+ if (y < 0 || y >= f->height || x < 0 || x >= f->width) {
+ return 0;
+ }
+
+ /* FIXME this assumes stride is aligned to 4 */
+ pixels[(y * (f->width + (f->stride >> 2))) + x] = pixel;
+
+ return 1;
+}
+
+#endif
diff --git a/src/modules/stars/stars.c b/src/modules/stars/stars.c
new file mode 100644
index 0000000..e009714
--- /dev/null
+++ b/src/modules/stars/stars.c
@@ -0,0 +1,63 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "draw.h"
+#include "fb.h"
+#include "rototiller.h"
+#include "starslib.h"
+
+/* Copyright (C) 2017 Philip J. Freeman <elektron@halo.nu> */
+
+static void stars(fb_fragment_t *fragment)
+{
+ static int initialized, z;
+ static struct universe* u;
+
+ struct return_point rp;
+ int x, y, width = fragment->width, height = fragment->height;
+
+ if (!initialized) {
+ z = 128;
+ srand(time(NULL) + getpid());
+
+ // Initialize the stars lib (and pre-add a bunch of stars)
+ new_universe(&u, width, height, z);
+ for(y=0; y<z; y++) {
+ while (process_point(u, &rp) != 0);
+ for(x=0; x<rand()%128; x++){
+ new_point(u);
+ }
+ }
+ initialized = 1;
+ }
+
+ // draw space (or blank the frame, if you prefer)
+ memset(fragment->buf, 0, ((fragment->width << 2) + fragment->stride) * fragment->height);
+
+ // draw stars
+ for (;;) {
+ int ret = process_point( u, &rp );
+ if (ret==0) break;
+ if (ret==1) draw_pixel(fragment, rp.x+(width/2), rp.y+(height/2),
+ makergb(0xFF, 0xFF, 0xFF, (float)rp.opacity/OPACITY_MAX)
+ );
+ }
+
+ // add stars at horizon
+ for (x=0; x<rand()%128; x++) {
+ new_point(u);
+ }
+}
+
+rototiller_renderer_t stars_renderer = {
+ .render = stars,
+ .name = "stars",
+ .description = "basic starfield",
+ .author = "Philip J Freeman <elektron@halo.nu>",
+ .license = "GPLv2",
+};
diff --git a/src/modules/stars/stars.h b/src/modules/stars/stars.h
new file mode 100644
index 0000000..70ef6f2
--- /dev/null
+++ b/src/modules/stars/stars.h
@@ -0,0 +1,8 @@
+#ifndef _STARS_H
+#define _STARS_H
+
+#include "fb.h"
+
+void stars(fb_fragment_t *fragment);
+
+#endif
diff --git a/src/modules/stars/starslib.c b/src/modules/stars/starslib.c
new file mode 100644
index 0000000..9d43062
--- /dev/null
+++ b/src/modules/stars/starslib.c
@@ -0,0 +1,133 @@
+/*
+ * a starfield simulation library from: https://github.com/ph1l/stars
+ * Copyright 2014 Philip J. Freeman <elektron@halo.nu>
+ */
+
+#include <stdlib.h>
+#ifdef DEBUG
+#include <stdio.h>
+#endif
+#include "starslib.h"
+
+struct points
+{
+ int x, y, z;
+ struct points *next;
+};
+
+void new_universe( struct universe** u, int width, int height, int depth )
+{
+ *u = malloc(sizeof(struct universe));
+
+ (*u)->width = width;
+ (*u)->height = height;
+ (*u)->depth = depth;
+
+ (*u)->iterator = NULL;
+ (*u)->points = NULL;
+ #ifdef DEBUG
+ printf("NEW UNIVERSE: %lx: (%i,%i,%i)\n", (long unsigned int )(*u), (*u)->width, (*u)->height, (*u)->depth);
+ #endif
+
+ return;
+}
+
+void new_point( struct universe* u )
+{
+
+ struct points* p_ptr = malloc(sizeof(struct points));
+
+ p_ptr->x = (rand()%u->width - (u->width/2)) * u->depth;
+ p_ptr->y = (rand()%u->height - (u->height/2)) * u->depth;
+ p_ptr->z = u->depth;
+
+ p_ptr->next = u->points;
+ u->points = p_ptr;
+ #ifdef DEBUG
+ printf("NEW POINT: %lx: (%i,%i,%i) next=%lx\n", (long unsigned int )p_ptr, p_ptr->x, p_ptr->y, p_ptr->z, (long unsigned int) p_ptr->next);
+ #endif
+
+ return;
+}
+
+void kill_point( struct universe* universe, struct points* to_kill )
+{
+
+ struct points *p_ptr, *last_ptr = NULL;
+
+
+ for ( p_ptr = universe->points; p_ptr != NULL; p_ptr = p_ptr->next)
+ {
+ if (p_ptr == to_kill)
+ {
+ #ifdef DEBUG
+ printf("KILL POINT: %lx: (%i,%i,%i).\n", (long unsigned int )p_ptr, p_ptr->x, p_ptr->y, p_ptr->z);
+ #endif
+ if (last_ptr == NULL)
+ {
+ universe->points = p_ptr->next;
+ } else {
+ last_ptr->next = p_ptr->next;
+ }
+ free(p_ptr);
+ } else {
+ last_ptr = p_ptr;
+ }
+ }
+ #ifdef DEBUG
+ printf("KILL POINT: %lx\n", (long unsigned int )p_ptr);
+ #endif
+ return;
+}
+
+int process_point( struct universe *u, struct return_point *rp )
+{
+
+ if ( u->iterator == NULL ) {
+ if (u->points == NULL){
+ return 0;
+ } else {
+ u->iterator = u->points;
+ }
+ }
+
+ if ( u->iterator->z == 0 ){
+ // Delete point that has reached us.
+ struct points *tmp = u->iterator;
+ u->iterator = u->iterator->next;
+ kill_point( u, tmp );
+ return(-1);
+ } else {
+ // Plot the point
+ int x, y;
+ x = u->iterator->x / u->iterator->z;
+ y = u->iterator->y / u->iterator->z;
+ if ( abs(x) >= u->width/2 || abs(y) >= u->height/2 ){
+ // Delete point that is off screen
+ struct points *tmp = u->iterator;
+ u->iterator = u->iterator->next;
+ kill_point( u, tmp );
+ if ( u->iterator == NULL ) {
+ return(0);
+ } else {
+ return(-1);
+ }
+ } else {
+ int m = OPACITY_MAX*((u->depth-u->iterator->z)*4)/u->depth;
+ if ( m>OPACITY_MAX ){ m=OPACITY_MAX; }
+ u->iterator->z = u->iterator->z - 1;
+ #ifdef DEBUG
+ printf("RETURN POINT: %lx\n", (long unsigned int )u->iterator);
+ #endif
+ u->iterator = u->iterator->next;
+ rp->x = x;
+ rp->y = y;
+ rp->opacity = m;
+ if ( u->iterator == NULL ) {
+ return(0);
+ } else {
+ return(1);
+ }
+ }
+ }
+}
diff --git a/src/modules/stars/starslib.h b/src/modules/stars/starslib.h
new file mode 100644
index 0000000..0c125a3
--- /dev/null
+++ b/src/modules/stars/starslib.h
@@ -0,0 +1,19 @@
+struct universe
+{
+ int width, height, depth;
+ struct points* points;
+ struct points* iterator;
+};
+
+void new_universe( struct universe** u, int width, int height, int depth );
+void new_point( struct universe* universe );
+
+#define OPACITY_MAX 8
+struct return_point
+{
+ int x, y;
+ int opacity;
+};
+
+int process_point( struct universe *u, struct return_point *rp );
+
diff --git a/src/rototiller.c b/src/rototiller.c
new file mode 100644
index 0000000..3fa9395
--- /dev/null
+++ b/src/rototiller.c
@@ -0,0 +1,87 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include "drmsetup.h"
+#include "fb.h"
+#include "fps.h"
+#include "rototiller.h"
+#include "util.h"
+
+/* Copyright (C) 2016 Vito Caputo <vcaputo@pengaru.com> */
+
+#define NUM_FB_PAGES 3
+/* ^ By triple-buffering, we can have a page tied up being displayed, another
+ * tied up submitted and waiting for vsync, and still not block on getting
+ * another page so we can begin rendering another frame before vsync. With
+ * just two pages we end up twiddling thumbs until the vsync arrives.
+ */
+
+extern rototiller_renderer_t roto32_renderer;
+extern rototiller_renderer_t roto64_renderer;
+extern rototiller_renderer_t ray_renderer;
+extern rototiller_renderer_t sparkler_renderer;
+extern rototiller_renderer_t stars_renderer;
+
+static rototiller_renderer_t *renderers[] = {
+ &roto32_renderer,
+ &roto64_renderer,
+ &ray_renderer,
+ &sparkler_renderer,
+ &stars_renderer,
+};
+
+
+static void renderer_select(int *renderer)
+{
+ int i;
+
+ printf("\nRenderers\n");
+ for (i = 0; i < nelems(renderers); i++) {
+ printf(" %i: %s - %s\n", i, renderers[i]->name, renderers[i]->description);
+ }
+
+ ask_num(renderer, nelems(renderers) - 1, "Select renderer", 0);
+}
+
+
+int main(int argc, const char *argv[])
+{
+ int drm_fd;
+ drmModeModeInfoPtr drm_mode;
+ uint32_t drm_crtc_id;
+ uint32_t drm_connector_id;
+ fb_t *fb;
+ int renderer;
+
+ drm_setup(&drm_fd, &drm_crtc_id, &drm_connector_id, &drm_mode);
+ renderer_select(&renderer);
+
+ pexit_if(!(fb = fb_new(drm_fd, drm_crtc_id, &drm_connector_id, 1, drm_mode, NUM_FB_PAGES)),
+ "unable to create fb");
+
+ pexit_if(!fps_setup(),
+ "unable to setup fps counter");
+
+ for (;;) {
+ fb_page_t *page;
+
+ fps_print(fb);
+
+ page = fb_page_get(fb);
+ renderers[renderer]->render(&page->fragment);
+ fb_page_put(fb, page);
+ }
+
+ fb_free(fb);
+ close(drm_fd);
+
+ return EXIT_SUCCESS;
+}
diff --git a/src/rototiller.h b/src/rototiller.h
new file mode 100644
index 0000000..0ff2c3f
--- /dev/null
+++ b/src/rototiller.h
@@ -0,0 +1,12 @@
+#ifndef _ROTOTILLER_H
+#define _ROTOTILLER_H
+
+typedef struct rototiller_renderer_t {
+ void (*render)(fb_fragment_t *);
+ char *name;
+ char *description;
+ char *author;
+ char *license;
+} rototiller_renderer_t;
+
+#endif
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..0e5825a
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,60 @@
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "util.h"
+
+#define SYSFS_CPU "/sys/devices/system/cpu/cpu"
+#define MAXCPUS 1024
+
+unsigned get_ncpus(void)
+{
+ char path[cstrlen(SYSFS_CPU "1024") + 1];
+ unsigned n;
+
+ for (n = 0; n < MAXCPUS; n++) {
+ snprintf(path, sizeof(path), "%s%u", SYSFS_CPU, n);
+ if (access(path, F_OK) == -1)
+ break;
+ }
+
+ return n == 0 ? 1 : n;
+}
+
+
+static void query(const char *prompt, const char *def, char *buf, int len)
+{
+ buf[0] = '\0';
+
+ printf("%s [%s]: ", prompt, def);
+ fflush(stdout);
+
+ fgets(buf, len, stdin);
+ if (buf[0] == '\0' || buf[0] == '\n') {
+ snprintf(buf, len, "%s", def);
+ } else if(strchr(buf, '\n')) {
+ *strchr(buf, '\n') = '\0';
+ }
+}
+
+
+void ask_string(char *buf, int len, const char *prompt, const char *def)
+{
+ query(prompt, def, buf, len);
+}
+
+
+void ask_num(int *res, int max, const char *prompt, int def)
+{
+ char buf[21], buf2[256];
+ int num;
+
+ snprintf(buf, sizeof(buf), "%i", def);
+ do {
+ query(prompt, buf, buf2, sizeof(buf2));
+ num = atoi(buf2); /* TODO: errors (strtol)*/
+ } while (num > max);
+
+ *res = num;
+}
diff --git a/src/util.h b/src/util.h
new file mode 100644
index 0000000..549b529
--- /dev/null
+++ b/src/util.h
@@ -0,0 +1,28 @@
+#ifndef _UTIL_H
+#define _UTIL_H
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define exit_if(_cond, _fmt, ...) \
+ if (_cond) { \
+ fprintf(stderr, "Fatal error: " _fmt "\n", ##__VA_ARGS__); \
+ exit(EXIT_FAILURE); \
+ }
+
+#define pexit_if(_cond, _fmt, ...) \
+ exit_if(_cond, _fmt ": %s", ##__VA_ARGS__, strerror(errno))
+
+#define nelems(_array) \
+ (sizeof(_array) / sizeof(_array[0]))
+
+#define cstrlen(_str) \
+ (sizeof(_str) - 1)
+
+unsigned get_ncpus(void);
+void ask_string(char *buf, int len, const char *prompt, const char *def);
+void ask_num(int *res, int max, const char *prompt, int def);
+
+#endif /* _UTIL_H */
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