3 files changed, 172 insertions, 1 deletions
diff --git a/src/modules/Makefile.am b/src/modules/Makefile.am
index 0ab81b7..1622814 100644
--- a/src/modules/Makefile.am
+++ b/src/modules/Makefile.am
@@ -1 +1 @@
-SUBDIRS = flui2d julia pixbounce plasma ray roto rtv snow sparkler stars submit swab
+SUBDIRS = flui2d julia montage pixbounce plasma ray roto rtv snow sparkler stars submit swab
diff --git a/src/modules/montage/Makefile.am b/src/modules/montage/Makefile.am
new file mode 100644
index 0000000..7465510
--- /dev/null
+++ b/src/modules/montage/Makefile.am
@@ -0,0 +1,3 @@
+noinst_LIBRARIES = libmontage.a
+libmontage_a_SOURCES = montage.c
+libmontage_a_CPPFLAGS = -I@top_srcdir@/src -I@top_srcdir@/src/libs
diff --git a/src/modules/montage/montage.c b/src/modules/montage/montage.c
new file mode 100644
index 0000000..068c6e0
--- /dev/null
+++ b/src/modules/montage/montage.c
@@ -0,0 +1,168 @@
+#include <math.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "fb.h"
+#include "rototiller.h"
+#include "settings.h"
+#include "util.h"
+
+/* Copyright (C) 2019 - Vito Caputo <vcaputo@pengaru.com> */
+
+typedef struct montage_context_t {
+	const rototiller_module_t	**modules;
+	const rototiller_module_t	*rtv_module;
+	void				**contexts;
+	size_t				n_modules;
+	unsigned			n_cpus;
+} montage_context_t;
+
+static void setup_next_module(montage_context_t *ctxt);
+static void * montage_create_context(unsigned num_cpus);
+static void montage_destroy_context(void *context);
+static void montage_prepare_frame(void *context, unsigned n_cpus, fb_fragment_t *fragment, rototiller_fragmenter_t *res_fragmenter);
+static void montage_render_fragment(void *context, unsigned cpu, fb_fragment_t *fragment);
+
+
+rototiller_module_t	montage_module = {
+	.create_context = montage_create_context,
+	.destroy_context = montage_destroy_context,
+	.prepare_frame = montage_prepare_frame,
+	.render_fragment = montage_render_fragment,
+	.name = "montage",
+	.description = "Rototiller montage",
+	.author = "Vito Caputo <vcaputo@pengaru.com>",
+	.license = "GPLv2",
+};
+
+
+static int skip_module(montage_context_t *ctxt, const rototiller_module_t *module)
+{
+	/* prevent recursion */
+	if (module == &montage_module)
+		return 1;
+
+	/* also prevents recursion, as rtv could run montage... */
+	if (module == ctxt->rtv_module)
+		return 1;
+
+	return 0;
+}
+
+
+static void * montage_create_context(unsigned num_cpus)
+{
+	montage_context_t	*ctxt = calloc(1, sizeof(montage_context_t));
+
+	ctxt->n_cpus = num_cpus;
+	rototiller_get_modules(&ctxt->modules, &ctxt->n_modules);
+
+	ctxt->contexts = calloc(ctxt->n_modules, sizeof(void *));
+	if (!ctxt->contexts) {
+		free(ctxt);
+
+		return NULL;
+	}
+
+	ctxt->rtv_module = rototiller_lookup_module("rtv");
+
+	for (int i = 0; i < ctxt->n_modules; i++) {
+		const rototiller_module_t	*module = ctxt->modules[i];
+
+		if (skip_module(ctxt, module))
+			continue;
+
+		if (module->create_context)	/* FIXME errors */
+			ctxt->contexts[i] = module->create_context(num_cpus);
+	}
+
+	return ctxt;
+}
+
+
+static void montage_destroy_context(void *context)
+{
+	montage_context_t	*ctxt = context;
+
+	for (int i = 0; i < ctxt->n_modules; i++) {
+		const rototiller_module_t	*module = ctxt->modules[i];
+
+		if (skip_module(ctxt, module))
+			continue;
+
+		if (!ctxt->contexts[i])
+			continue;
+
+		 module->destroy_context(ctxt->contexts[i]);
+	}
+
+	free(context);
+}
+
+
+/* The fragmenter in montage is serving double-duty:
+ * 1. it divides the frame into subfragments for threaded rendering
+ * 2. it determines which modules will be rendered where via fragment->number
+ */
+static int montage_fragmenter(void *context, const fb_fragment_t *fragment, unsigned number, fb_fragment_t *res_fragment)
+{
+	montage_context_t	*ctxt = context;
+	float			root = sqrtf((float)ctxt->n_modules);
+	int			ret;
+
+	ret = fb_fragment_tile_single(fragment, fragment->frame_height / root, number, res_fragment);
+	if (!ret)
+		return 0;
+
+	if (number >= ctxt->n_modules)
+		return 0;
+
+	/* as these tiles are frames of their own rather than subfragments, override these values */
+	res_fragment->x = res_fragment->y = 0;
+	res_fragment->frame_width = res_fragment->width;
+	res_fragment->frame_height = res_fragment->height;
+
+	return ret;
+}
+
+
+
+static void montage_prepare_frame(void *context, unsigned n_cpus, fb_fragment_t *fragment, rototiller_fragmenter_t *res_fragmenter)
+{
+	montage_context_t	*ctxt = context;
+
+	*res_fragmenter = montage_fragmenter;
+}
+
+
+static void montage_render_fragment(void *context, unsigned cpu, fb_fragment_t *fragment)
+{
+	montage_context_t		*ctxt = context;
+	const rototiller_module_t	*module = ctxt->modules[fragment->number];
+
+	if (skip_module(ctxt, module))
+		return;
+
+	/* since we're *already* in a threaded render of tiles, no further
+	 * threading within the montage tiles is desirable, so the per-module
+	 * render is done explicitly serially here in an open-coded ad-hoc
+	 * fashion for now. FIXME TODO: move this into rototiller.c
+	 */
+	if (module->prepare_frame) {
+		rototiller_fragmenter_t	unused;
+
+		/* XXX FIXME: ignoring the fragmenter here is a violation of the module API,
+		 * rototiller.c should have a module render interface with explicit non-threading
+		 * that still does all the necessary fragmenting as needed.
+		 *
+		 * Today, I can get away with this, because montage is the only module that's
+		 * sensitive to this aspect of the API and it skips itself.
+		 */
+
+		module->prepare_frame(ctxt->contexts[fragment->number], 1, fragment, &unused);
+	}
+
+	if (module->render_fragment)
+		module->render_fragment(ctxt->contexts[fragment->number], 0, fragment);
+}
+