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authorVito Caputo <vcaputo@pengaru.com>2018-03-19 21:39:09 -0700
committerVito Caputo <vcaputo@pengaru.com>2018-03-19 22:02:08 -0700
commitb5bc962e834992eeba2abdd10f6e37ee2ba20295 (patch)
tree11bf58a64208806817c0fcab481588086297ce6c /src/libs/ray
parent3b9a4861d6937a66b03791b5b497e47c52189a7d (diff)
ray: libize raytracer core, introduces src/libs
This is the first step of breaking out all the core rendering stuffs into reusable libraries and making modules purely compositional, consumers of various included rendering/effects libraries. Expect multiple modules leveraging libray for a variety of scenes and such. Also expect compositions mixing the various libraries for more interesting visuals.
Diffstat (limited to 'src/libs/ray')
-rw-r--r--src/libs/ray/ray_3f.h154
-rw-r--r--src/libs/ray/ray_camera.c70
-rw-r--r--src/libs/ray/ray_camera.h84
-rw-r--r--src/libs/ray/ray_color.h29
-rw-r--r--src/libs/ray/ray_euler.c90
-rw-r--r--src/libs/ray/ray_euler.h33
-rw-r--r--src/libs/ray/ray_light_emitter.h18
-rw-r--r--src/libs/ray/ray_object.h18
-rw-r--r--src/libs/ray/ray_object_light.h14
-rw-r--r--src/libs/ray/ray_object_plane.h16
-rw-r--r--src/libs/ray/ray_object_point.h15
-rw-r--r--src/libs/ray/ray_object_sphere.h16
-rw-r--r--src/libs/ray/ray_object_type.h12
-rw-r--r--src/libs/ray/ray_ray.h11
-rw-r--r--src/libs/ray/ray_render.c251
-rw-r--r--src/libs/ray/ray_render.h15
-rw-r--r--src/libs/ray/ray_render_object.h121
-rw-r--r--src/libs/ray/ray_render_object_plane.h61
-rw-r--r--src/libs/ray/ray_render_object_point.h45
-rw-r--r--src/libs/ray/ray_render_object_sphere.h90
-rw-r--r--src/libs/ray/ray_scene.h16
-rw-r--r--src/libs/ray/ray_surface.h15
22 files changed, 1194 insertions, 0 deletions
diff --git a/src/libs/ray/ray_3f.h b/src/libs/ray/ray_3f.h
new file mode 100644
index 0000000..2c04a5a
--- /dev/null
+++ b/src/libs/ray/ray_3f.h
@@ -0,0 +1,154 @@
+#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(const ray_3f_t *a, const 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(const ray_3f_t *a, const 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(const 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(const ray_3f_t *a, const 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(const 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(const 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(const ray_3f_t *a, const 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(const 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(const ray_3f_t *v)
+{
+ return ray_3f_mult_scalar(v, 1.0f / ray_3f_length(v));
+}
+
+
+/* return the distance between two arbitrary points */
+static inline float ray_3f_distance(const ray_3f_t *a, const ray_3f_t *b)
+{
+ ray_3f_t delta = ray_3f_sub(a, b);
+
+ return ray_3f_length(&delta);
+}
+
+
+/* return the cross product of two unit vectors */
+static inline ray_3f_t ray_3f_cross(const ray_3f_t *a, const 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(const ray_3f_t *a, const 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(const ray_3f_t *a, const 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/libs/ray/ray_camera.c b/src/libs/ray/ray_camera.c
new file mode 100644
index 0000000..b942cf3
--- /dev/null
+++ b/src/libs/ray/ray_camera.c
@@ -0,0 +1,70 @@
+#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(const ray_camera_t *camera, ray_camera_frame_t *frame)
+{
+ ray_3f_t forward, left, up, right, down;
+ float half_horiz = (float)camera->width * 0.5f;
+ float half_vert = (float)camera->height * 0.5f;
+
+ 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);
+}
+
+
+/* Prepare a frame of camera projection, initializing res_frame. */
+void ray_camera_frame_prepare(const ray_camera_t *camera, ray_camera_frame_t *res_frame)
+{
+ res_frame->camera = camera;
+
+ project_corners(camera, res_frame);
+
+ res_frame->x_delta = 1.0f / (float)camera->width;
+ res_frame->y_delta = 1.0f / (float)camera->height;
+}
+
+
+/* Begin a frame's fragment, initializing frame and ray. */
+void ray_camera_fragment_begin(ray_camera_frame_t *frame, fb_fragment_t *fb_fragment, ray_ray_t *res_ray, ray_camera_fragment_t *res_fragment)
+{
+ res_fragment->frame = frame;
+ res_fragment->fb_fragment = fb_fragment;
+ res_fragment->ray = res_ray;
+
+ res_fragment->x = res_fragment->y = 0;
+
+ res_fragment->x_alpha = frame->x_delta * (float)fb_fragment->x;
+ res_fragment->y_alpha = frame->y_delta * (float)fb_fragment->y;
+
+ res_fragment->cur_w = ray_3f_lerp(&frame->nw, &frame->sw, res_fragment->y_alpha);
+ res_fragment->cur_e = ray_3f_lerp(&frame->ne, &frame->se, res_fragment->y_alpha);
+
+ res_ray->origin = frame->camera->position;
+ res_ray->direction = ray_3f_nlerp(&res_fragment->cur_w, &res_fragment->cur_e, res_fragment->x_alpha);
+}
diff --git a/src/libs/ray/ray_camera.h b/src/libs/ray/ray_camera.h
new file mode 100644
index 0000000..e393beb
--- /dev/null
+++ b/src/libs/ray/ray_camera.h
@@ -0,0 +1,84 @@
+#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 {
+ const ray_camera_t *camera; /* the camera supplied to frame_begin() */
+
+ ray_3f_t nw, ne, sw, se; /* directions pointing through the corners of the frame fragment */
+ float x_delta, y_delta; /* interpolation step delta along the x and y axis */
+} ray_camera_frame_t;
+
+
+typedef struct ray_camera_fragment_t {
+ ray_camera_frame_t *frame; /* the frame supplied to fragment_begin() */
+ fb_fragment_t *fb_fragment; /* the fragment supplied to fragment_begin() */
+ ray_ray_t *ray; /* the ray supplied to frame_begin(), which gets updated as we step through the frame. */
+
+ 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 */
+ unsigned x, y; /* integral position within frame fragment */
+} ray_camera_fragment_t;
+
+
+void ray_camera_frame_prepare(const ray_camera_t *camera, ray_camera_frame_t *res_frame);
+void ray_camera_fragment_begin(ray_camera_frame_t *frame, fb_fragment_t *fb_fragment, ray_ray_t *res_ray, ray_camera_fragment_t *res_fragment);
+
+
+/* Step the ray through the fragment on the x axis, returns 1 when rays remain on this axis, 0 at the end. */
+/* When 1 is returned, fragment->ray is left pointing through the new coordinate. */
+static inline int ray_camera_fragment_x_step(ray_camera_fragment_t *fragment)
+{
+ fragment->x++;
+
+ if (fragment->x >= fragment->fb_fragment->width) {
+ fragment->x = 0;
+ fragment->x_alpha = fragment->frame->x_delta * (float)fragment->fb_fragment->x;
+ return 0;
+ }
+
+ fragment->x_alpha += fragment->frame->x_delta;
+ fragment->ray->direction = ray_3f_nlerp(&fragment->cur_w, &fragment->cur_e, fragment->x_alpha);
+
+ return 1;
+}
+
+
+/* Step the ray through the fragment on the y axis, returns 1 when rays remain on this axis, 0 at the end. */
+/* When 1 is returned, fragment->ray is left pointing through the new coordinate. */
+static inline int ray_camera_fragment_y_step(ray_camera_fragment_t *fragment)
+{
+ fragment->y++;
+
+ if (fragment->y >= fragment->fb_fragment->height) {
+ fragment->y = 0;
+ fragment->y_alpha = fragment->frame->y_delta * (float)fragment->fb_fragment->y;
+ return 0;
+ }
+
+ fragment->y_alpha += fragment->frame->y_delta;
+ fragment->cur_w = ray_3f_lerp(&fragment->frame->nw, &fragment->frame->sw, fragment->y_alpha);
+ fragment->cur_e = ray_3f_lerp(&fragment->frame->ne, &fragment->frame->se, fragment->y_alpha);
+ fragment->ray->direction = ray_3f_nlerp(&fragment->cur_w, &fragment->cur_e, fragment->x_alpha);
+
+ return 1;
+}
+
+#endif
diff --git a/src/libs/ray/ray_color.h b/src/libs/ray/ray_color.h
new file mode 100644
index 0000000..9fe62c1
--- /dev/null
+++ b/src/libs/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/libs/ray/ray_euler.c b/src/libs/ray/ray_euler.c
new file mode 100644
index 0000000..f143e25
--- /dev/null
+++ b/src/libs/ray/ray_euler.c
@@ -0,0 +1,90 @@
+#include <assert.h>
+#include <math.h>
+
+#include "ray_3f.h"
+#include "ray_euler.h"
+
+/* produce orthonormal basis vectors from euler angles, rotated in the specified order */
+void ray_euler_basis(const 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);
+
+ /* Rotation matrices from http://www.songho.ca/opengl/gl_anglestoaxes.html */
+ switch (e->order) {
+ case RAY_EULER_ORDER_PYR:
+ /* pitch, yaw, roll */
+ 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;
+
+ forward->x = sin_yaw;
+ forward->y = -sin_pitch * cos_yaw;
+ forward->z = cos_pitch * cos_yaw;
+ break;
+
+ case RAY_EULER_ORDER_YRP:
+ /* yaw, roll, pitch */
+ up->x = -cos_yaw * sin_roll * cos_pitch + sin_yaw * sin_pitch;
+ up->y = cos_roll * cos_pitch;
+ up->z = sin_yaw * sin_roll * cos_pitch + cos_yaw * sin_pitch;
+
+ forward->x = cos_yaw * sin_roll * sin_pitch + sin_yaw * cos_pitch;
+ forward->y = -cos_roll * sin_pitch;
+ forward->z = -sin_yaw * sin_roll * sin_pitch + cos_yaw * cos_pitch;
+ break;
+
+ case RAY_EULER_ORDER_RPY:
+ /* roll, pitch, yaw */
+ up->x = -sin_roll * cos_pitch;
+ up->y = cos_roll * cos_pitch;
+ up->z = sin_pitch;
+
+ forward->x = cos_roll * sin_yaw + sin_roll * sin_pitch * cos_yaw;
+ forward->y = sin_roll * sin_yaw - cos_roll * sin_pitch * cos_yaw;
+ forward->z = cos_pitch * cos_yaw;
+ break;
+
+ case RAY_EULER_ORDER_PRY:
+ /* pitch, roll, yaw */
+ up->x = -sin_roll;
+ up->y = cos_pitch * cos_roll;
+ up->z = sin_pitch * cos_roll;
+
+ forward->x = cos_roll * sin_yaw;
+ forward->y = cos_pitch * sin_roll * sin_yaw - sin_pitch * cos_yaw;
+ forward->z = sin_pitch * sin_roll * sin_yaw + cos_pitch * cos_yaw;
+ break;
+
+ case RAY_EULER_ORDER_RYP:
+ /* roll, yaw, pitch */
+ up->x = -sin_roll * cos_pitch + cos_roll * sin_yaw * sin_pitch;
+ up->y = cos_roll * cos_pitch + sin_roll * sin_yaw * sin_pitch;
+ up->z = cos_yaw * sin_pitch;
+
+ forward->x = sin_roll * sin_pitch + cos_roll * sin_yaw * cos_pitch;
+ forward->y = -cos_roll * sin_pitch + sin_roll * sin_yaw * cos_pitch;
+ forward->z = cos_yaw * cos_pitch;
+ break;
+
+ case RAY_EULER_ORDER_YPR:
+ /* yaw, pitch, roll */
+ up->x = -cos_yaw * sin_roll + sin_yaw * sin_pitch * cos_roll;
+ up->y = cos_pitch * cos_roll;
+ up->z = sin_yaw * sin_roll + cos_yaw * sin_pitch * cos_roll;
+
+ forward->x = sin_yaw * cos_pitch;
+ forward->y = -sin_pitch;
+ forward->z = cos_yaw * cos_pitch;
+ break;
+
+ default:
+ assert(0);
+ }
+
+ *left = ray_3f_cross(up, forward);
+}
diff --git a/src/libs/ray/ray_euler.h b/src/libs/ray/ray_euler.h
new file mode 100644
index 0000000..39da17e
--- /dev/null
+++ b/src/libs/ray/ray_euler.h
@@ -0,0 +1,33 @@
+#ifndef _RAY_EULER_H
+#define _RAY_EULER_H
+
+#include <math.h>
+
+#include "ray_3f.h"
+
+/* Desired order to apply euler angle rotations */
+typedef enum ray_euler_order_t {
+ RAY_EULER_ORDER_PYR,
+ RAY_EULER_ORDER_YRP,
+ RAY_EULER_ORDER_RPY,
+ RAY_EULER_ORDER_PRY,
+ RAY_EULER_ORDER_RYP,
+ RAY_EULER_ORDER_YPR,
+} ray_euler_order_t;
+
+/* euler angles are convenient for describing orientation */
+typedef struct ray_euler_t {
+ ray_euler_order_t order; /* order to apply rotations in */
+ 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))
+
+void ray_euler_basis(const ray_euler_t *e, ray_3f_t *forward, ray_3f_t *up, ray_3f_t *left);
+
+#endif
diff --git a/src/libs/ray/ray_light_emitter.h b/src/libs/ray/ray_light_emitter.h
new file mode 100644
index 0000000..3b5509e
--- /dev/null
+++ b/src/libs/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/libs/ray/ray_object.h b/src/libs/ray/ray_object.h
new file mode 100644
index 0000000..fc5ae1b
--- /dev/null
+++ b/src/libs/ray/ray_object.h
@@ -0,0 +1,18 @@
+#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"
+
+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;
+
+#endif
diff --git a/src/libs/ray/ray_object_light.h b/src/libs/ray/ray_object_light.h
new file mode 100644
index 0000000..ca9bac9
--- /dev/null
+++ b/src/libs/ray/ray_object_light.h
@@ -0,0 +1,14 @@
+#ifndef _RAY_OBJECT_LIGHT_H
+#define _RAY_OBJECT_LIGHT_H
+
+#include "ray_light_emitter.h"
+#include "ray_object_type.h"
+
+
+typedef struct ray_object_light_t {
+ ray_object_type_t type;
+ float brightness;
+ ray_light_emitter_t emitter;
+} ray_object_light_t;
+
+#endif
diff --git a/src/libs/ray/ray_object_plane.h b/src/libs/ray/ray_object_plane.h
new file mode 100644
index 0000000..96ed437
--- /dev/null
+++ b/src/libs/ray/ray_object_plane.h
@@ -0,0 +1,16 @@
+#ifndef _RAY_OBJECT_PLANE_H
+#define _RAY_OBJECT_PLANE_H
+
+#include "ray_3f.h"
+#include "ray_object_type.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;
+
+#endif
diff --git a/src/libs/ray/ray_object_point.h b/src/libs/ray/ray_object_point.h
new file mode 100644
index 0000000..5685fdc
--- /dev/null
+++ b/src/libs/ray/ray_object_point.h
@@ -0,0 +1,15 @@
+#ifndef _RAY_OBJECT_POINT_H
+#define _RAY_OBJECT_POINT_H
+
+#include "ray_3f.h"
+#include "ray_object_type.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;
+
+#endif
diff --git a/src/libs/ray/ray_object_sphere.h b/src/libs/ray/ray_object_sphere.h
new file mode 100644
index 0000000..71b6334
--- /dev/null
+++ b/src/libs/ray/ray_object_sphere.h
@@ -0,0 +1,16 @@
+#ifndef _RAY_OBJECT_SPHERE_H
+#define _RAY_OBJECT_SPHERE_H
+
+#include "ray_3f.h"
+#include "ray_object_type.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;
+
+#endif
diff --git a/src/libs/ray/ray_object_type.h b/src/libs/ray/ray_object_type.h
new file mode 100644
index 0000000..ab797d2
--- /dev/null
+++ b/src/libs/ray/ray_object_type.h
@@ -0,0 +1,12 @@
+#ifndef _RAY_OBJECT_TYPE_H
+#define _RAY_OBJECT_TYPE_H
+
+typedef enum ray_object_type_t {
+ RAY_OBJECT_TYPE_SENTINEL,
+ 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/libs/ray/ray_ray.h b/src/libs/ray/ray_ray.h
new file mode 100644
index 0000000..91469a2
--- /dev/null
+++ b/src/libs/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/libs/ray/ray_render.c b/src/libs/ray/ray_render.c
new file mode 100644
index 0000000..8b930f6
--- /dev/null
+++ b/src/libs/ray/ray_render.c
@@ -0,0 +1,251 @@
+#include <stdlib.h>
+#include <math.h>
+
+#include "fb.h"
+
+#include "ray_camera.h"
+#include "ray_color.h"
+#include "ray_render_object.h"
+#include "ray_ray.h"
+#include "ray_scene.h"
+
+#define MAX_RECURSION_DEPTH 4
+#define MIN_RELEVANCE 0.05f
+
+typedef struct ray_render_t {
+ const ray_scene_t *scene; /* scene being rendered */
+ const ray_camera_t *camera; /* camera rendering the scene */
+
+ ray_color_t ambient_light;
+ ray_camera_frame_t frame;
+
+ ray_render_object_t objects[];
+} ray_render_t;
+
+/* Determine if the ray is obstructed by an object within the supplied distance, for shadows */
+static inline int ray_is_obstructed(ray_render_t *render, unsigned depth, ray_ray_t *ray, float distance)
+{
+ ray_render_object_t *object;
+
+ for (object = render->objects; object->type; object++) {
+ float ood;
+
+ if (ray_render_object_intersects_ray(object, depth, ray, &ood) &&
+ ood < distance) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
+/* shadow test */
+static inline int point_is_shadowed(ray_render_t *render, unsigned depth, ray_3f_t *light_direction, float distance, ray_3f_t *point)
+{
+ ray_ray_t shadow_ray;
+
+ shadow_ray.direction = *light_direction;
+ shadow_ray.origin = *point;
+
+ if (ray_is_obstructed(render, depth + 1, &shadow_ray, distance))
+ return 1;
+
+ return 0;
+}
+
+
+/* a faster powf() that's good enough for our purposes.
+ * XXX: note there's a faster technique which exploits the IEEE floating point format:
+ * https://github.com/ekmett/approximate/blob/master/cbits/fast.c#L185
+ */
+static inline float approx_powf(float x, float y)
+{
+ return expf(y * logf(x));
+}
+
+
+/* Determine the color @ distance on ray on object viewed from origin */
+static inline ray_color_t shade_intersection(ray_render_t *render, ray_render_object_t *object, ray_ray_t *ray, ray_3f_t *intersection, ray_3f_t *normal, unsigned depth, float *res_reflectivity)
+{
+ ray_surface_t surface = ray_render_object_surface(object, intersection);
+ ray_color_t color = ray_3f_mult(&surface.color, &render->ambient_light);
+ ray_object_t *light;
+
+ /* visit lights for shadows and illumination */
+ for (light = render->scene->lights; light->type; light++) {
+ ray_3f_t lvec = ray_3f_sub(&light->light.emitter.point.center, intersection);
+ float ldist = ray_3f_length(&lvec);
+ float lvec_normal_dot;
+
+ lvec = ray_3f_mult_scalar(&lvec, (1.0f / ldist)); /* normalize lvec */
+#if 1
+ if (point_is_shadowed(render, depth, &lvec, ldist, intersection))
+ 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);
+ float intensity = light->light.brightness * (1.0 / (ldist * ldist));
+ ray_color_t diffuse;
+
+ diffuse = ray_3f_mult_scalar(&surface.color, lvec_normal_dot);
+ diffuse = ray_3f_mult_scalar(&diffuse, surface.diffuse);
+ color = ray_3f_add(&color, &diffuse);
+
+ if (rvec_lvec_dot > 0) {
+ ray_color_t specular;
+
+ /* FIXME: assumes light is a point for its color */
+ specular = ray_3f_mult_scalar(&light->light.emitter.point.surface.color, approx_powf(rvec_lvec_dot, surface.highlight_exponent));
+ specular = ray_3f_mult_scalar(&specular, surface.specular);
+ color = ray_3f_add(&color, &specular);
+ }
+
+ color = ray_3f_mult_scalar(&color, intensity);
+#else
+ ray_color_t diffuse;
+
+ diffuse = ray_3f_mult_scalar(&surface.color, lvec_normal_dot);
+ color = ray_3f_add(&color, &diffuse);
+#endif
+ }
+ }
+
+ /* for now just treat specular as the reflectivity */
+ *res_reflectivity = surface.specular;
+
+ return color;
+}
+
+
+static inline ray_render_object_t * find_nearest_intersection(ray_render_t *render, ray_render_object_t *reflector, ray_ray_t *ray, unsigned depth, float *res_distance)
+{
+ ray_render_object_t *nearest_object = NULL;
+ float nearest_object_distance = INFINITY;
+ ray_render_object_t *object;
+
+ for (object = render->objects; object->type; object++) {
+ float distance;
+
+ /* Don't bother checking if a reflected ray intersects the object reflecting it,
+ * reflector = NULL for primary rays, which will never compare as true here. */
+ if (object == reflector)
+ continue;
+
+ /* Does this ray intersect object? */
+ if (ray_render_object_intersects_ray(object, depth, ray, &distance)) {
+ /* Is it the nearest intersection? */
+ if (distance < nearest_object_distance) {
+ nearest_object = object;
+ nearest_object_distance = distance;
+ }
+ }
+ }
+
+ if (nearest_object)
+ *res_distance = nearest_object_distance;
+
+ return nearest_object;
+}
+
+
+static inline ray_color_t trace_ray(ray_render_t *render, ray_ray_t *primary_ray)
+{
+ ray_color_t color = { .x = 0.0f, .y = 0.0f, .z = 0.0f };
+ ray_3f_t intersection, normal;
+ ray_render_object_t *reflector = NULL;
+ float relevance = 1.0f, reflectivity;
+ unsigned depth = 0;
+ ray_ray_t reflected_ray, *ray = primary_ray;
+
+ do {
+ ray_render_object_t *nearest_object;
+ float nearest_distance;
+
+ if (reflector) {
+ float dot = ray_3f_dot(&ray->direction, &normal);
+ ray_3f_t new_direction = ray_3f_mult_scalar(&normal, dot * 2.0f);
+
+ new_direction = ray_3f_sub(&ray->direction, &new_direction);
+
+ reflected_ray.origin = intersection;
+ reflected_ray.direction = new_direction;
+
+ ray = &reflected_ray;
+ }
+
+ nearest_object = find_nearest_intersection(render, reflector, ray, depth, &nearest_distance);
+ if (nearest_object) {
+ ray_3f_t more_color;
+ ray_3f_t rvec;
+
+ rvec = ray_3f_mult_scalar(&ray->direction, nearest_distance);
+ intersection = ray_3f_add(&ray->origin, &rvec);
+ normal = ray_render_object_normal(nearest_object, &intersection);
+
+ more_color = shade_intersection(render, nearest_object, ray, &intersection, &normal, depth, &reflectivity);
+ more_color = ray_3f_mult_scalar(&more_color, relevance);
+ color = ray_3f_add(&color, &more_color);
+ }
+
+ reflector = nearest_object;
+ } while (reflector && (++depth < MAX_RECURSION_DEPTH) && (relevance *= reflectivity) >= MIN_RELEVANCE);
+
+ return color;
+}
+
+
+void ray_render_trace_fragment(ray_render_t *render, fb_fragment_t *fb_fragment)
+{
+ uint32_t *buf = fb_fragment->buf;
+ ray_camera_fragment_t fragment;
+ ray_ray_t ray;
+
+ ray_camera_fragment_begin(&render->frame, fb_fragment, &ray, &fragment);
+ do {
+ do {
+ *buf = ray_color_to_uint32_rgb(trace_ray(render, &ray));
+ buf++;
+ } while (ray_camera_fragment_x_step(&fragment));
+
+ buf = ((void *)buf) + fb_fragment->stride;
+ } while (ray_camera_fragment_y_step(&fragment));
+}
+
+
+/* prepare the scene for rendering with camera, must be called whenever anything in the scene+camera pair has been changed. */
+/* this is basically a time for the raytracer to precompute whatever it can which otherwise ends up occurring per-ray */
+/* the camera is included so primary rays which all have a common origin may be optimized for */
+ray_render_t * ray_render_new(const ray_scene_t *scene, const ray_camera_t *camera)
+{
+ ray_render_t *render;
+ ray_object_t *object;
+ unsigned i;
+
+ for (i = 0, object = scene->objects; object->type; object++)
+ i++;
+
+ render = malloc(sizeof(ray_render_t) + i * sizeof(ray_render_object_t));
+ if (!render)
+ return NULL;
+
+ render->scene = scene;
+ render->camera = camera;
+
+ render->ambient_light = ray_3f_mult_scalar(&scene->ambient_color, scene->ambient_brightness);
+ ray_camera_frame_prepare(camera, &render->frame);
+
+ for (i = 0, object = scene->objects; object->type; object++)
+ render->objects[i++] = ray_render_object_prepare(object, camera);
+
+ return render;
+}
+
+
+void ray_render_free(ray_render_t *render)
+{
+ free(render);
+}
diff --git a/src/libs/ray/ray_render.h b/src/libs/ray/ray_render.h
new file mode 100644
index 0000000..dfd769f
--- /dev/null
+++ b/src/libs/ray/ray_render.h
@@ -0,0 +1,15 @@
+#ifndef _RAY_RENDER_H
+#define _RAY_RENDER_H
+
+#include "fb.h"
+
+#include "ray_camera.h"
+#include "ray_scene.h"
+
+typedef struct ray_render_t ray_render_t;
+
+ray_render_t * ray_render_new(const ray_scene_t *scene, const ray_camera_t *camera);
+void ray_render_free(ray_render_t *render);
+void ray_render_trace_fragment(ray_render_t *render, fb_fragment_t *fb_fragment);
+
+#endif
diff --git a/src/libs/ray/ray_render_object.h b/src/libs/ray/ray_render_object.h
new file mode 100644
index 0000000..1136eee
--- /dev/null
+++ b/src/libs/ray/ray_render_object.h
@@ -0,0 +1,121 @@
+#ifndef _RAY_RENDER_OBJECT_H
+#define _RAY_RENDER_OBJECT_H
+
+#include <assert.h>
+
+#include "ray_camera.h"
+#include "ray_object.h"
+#include "ray_object_type.h"
+#include "ray_render_object_plane.h"
+#include "ray_render_object_point.h"
+#include "ray_render_object_sphere.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+typedef union ray_render_object_t {
+ ray_object_type_t type;
+ ray_render_object_sphere_t sphere;
+ ray_render_object_point_t point;
+ ray_render_object_plane_t plane;
+} ray_render_object_t;
+
+
+
+/* Prepare an object for rendering.
+ * If the object has any pre-calculating to do, this is where it happens.
+ * The pre-calculated stuff is object-resident under a _prepared struct member.
+ */
+static inline ray_render_object_t ray_render_object_prepare(const ray_object_t *object, const ray_camera_t *camera)
+{
+ ray_render_object_t prepared = { .type = object->type };
+
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ prepared.sphere = ray_render_object_sphere_prepare(&object->sphere, camera);
+ break;
+
+ case RAY_OBJECT_TYPE_POINT:
+ prepared.point = ray_render_object_point_prepare(&object->point, camera);
+ break;
+
+ case RAY_OBJECT_TYPE_PLANE:
+ prepared.plane = ray_render_object_plane_prepare(&object->plane, camera);
+ break;
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ /* TODO */
+ break;
+
+ default:
+ assert(0);
+ }
+
+ return prepared;
+}
+
+
+/* Determine if a ray intersects object.
+ * If the object is intersected, store where along the ray the intersection occurs in res_distance.
+ */
+static inline int ray_render_object_intersects_ray(ray_render_object_t *object, unsigned depth, ray_ray_t *ray, float *res_distance)
+{
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ return ray_render_object_sphere_intersects_ray(&object->sphere, depth, ray, res_distance);
+
+ case RAY_OBJECT_TYPE_POINT:
+ return ray_render_object_point_intersects_ray(&object->point, depth, ray, res_distance);
+
+ case RAY_OBJECT_TYPE_PLANE:
+ return ray_render_object_plane_intersects_ray(&object->plane, depth, ray, res_distance);
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ /* TODO */
+ default:
+ assert(0);
+ }
+}
+
+
+/* Return the surface normal of object @ point */
+static inline ray_3f_t ray_render_object_normal(ray_render_object_t *object, ray_3f_t *point)
+{
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ return ray_render_object_sphere_normal(&object->sphere, point);
+
+ case RAY_OBJECT_TYPE_POINT:
+ return ray_render_object_point_normal(&object->point, point);
+
+ case RAY_OBJECT_TYPE_PLANE:
+ return ray_render_object_plane_normal(&object->plane, point);
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ /* TODO */
+ default:
+ assert(0);
+ }
+}
+
+
+/* Return the surface of object @ point */
+static inline ray_surface_t ray_render_object_surface(ray_render_object_t *object, ray_3f_t *point)
+{
+ switch (object->type) {
+ case RAY_OBJECT_TYPE_SPHERE:
+ return ray_render_object_sphere_surface(&object->sphere, point);
+
+ case RAY_OBJECT_TYPE_POINT:
+ return ray_render_object_point_surface(&object->point, point);
+
+ case RAY_OBJECT_TYPE_PLANE:
+ return ray_render_object_plane_surface(&object->plane, point);
+
+ case RAY_OBJECT_TYPE_LIGHT:
+ /* TODO */
+ default:
+ assert(0);
+ }
+}
+
+#endif
diff --git a/src/libs/ray/ray_render_object_plane.h b/src/libs/ray/ray_render_object_plane.h
new file mode 100644
index 0000000..6e00089
--- /dev/null
+++ b/src/libs/ray/ray_render_object_plane.h
@@ -0,0 +1,61 @@
+#ifndef _RAY_RENDER_OBJECT_PLANE_H
+#define _RAY_RENDER_OBJECT_PLANE_H
+
+#include "ray_3f.h"
+#include "ray_camera.h"
+#include "ray_object_plane.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_render_object_plane_t {
+ ray_object_plane_t object;
+ float primary_dot_plus;
+} ray_render_object_plane_t;
+
+
+static ray_render_object_plane_t ray_render_object_plane_prepare(const ray_object_plane_t *plane, const ray_camera_t *camera)
+{
+ ray_render_object_plane_t prepared = { .object = *plane };
+
+ prepared.primary_dot_plus = ray_3f_dot(&plane->normal, &camera->position) + plane->distance;
+
+ return prepared;
+}
+
+
+static inline int ray_render_object_plane_intersects_ray(ray_render_object_plane_t *plane, unsigned depth, ray_ray_t *ray, float *res_distance)
+{
+ float d = ray_3f_dot(&plane->object.normal, &ray->direction);
+
+ if (d < 0.0f) {
+ float distance = plane->primary_dot_plus;
+
+ if (depth)
+ distance = (ray_3f_dot(&plane->object.normal, &ray->origin) + plane->object.distance);
+
+ distance /= -d;
+ if (distance > 0.0f) {
+ *res_distance = distance;
+
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
+static inline ray_3f_t ray_render_object_plane_normal(ray_render_object_plane_t *plane, ray_3f_t *point)
+{
+ return plane->object.normal;
+}
+
+
+static inline ray_surface_t ray_render_object_plane_surface(ray_render_object_plane_t *plane, ray_3f_t *point)
+{
+ return plane->object.surface;
+}
+
+#endif
diff --git a/src/libs/ray/ray_render_object_point.h b/src/libs/ray/ray_render_object_point.h
new file mode 100644
index 0000000..52c6fd6
--- /dev/null
+++ b/src/libs/ray/ray_render_object_point.h
@@ -0,0 +1,45 @@
+#ifndef _RAY_RENDER_OBJECT_POINT_H
+#define _RAY_RENDER_OBJECT_POINT_H
+
+#include "ray_3f.h"
+#include "ray_camera.h"
+#include "ray_object_point.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_render_object_point_t {
+ ray_object_point_t object;
+} ray_render_object_point_t;
+
+
+static ray_render_object_point_t ray_render_object_point_prepare(const ray_object_point_t *point, const ray_camera_t *camera)
+{
+ ray_render_object_point_t prepared = { .object = *point };
+
+ return prepared;
+}
+
+
+static inline int ray_render_object_point_intersects_ray(ray_render_object_point_t *point, unsigned depth, ray_ray_t *ray, float *res_distance)
+{
+ /* TODO: determine a ray:point intersection */
+ return 0;
+}
+
+
+static inline ray_3f_t ray_render_object_point_normal(ray_render_object_point_t *point, ray_3f_t *_point)
+{
+ ray_3f_t normal;
+
+ return normal;
+}
+
+
+static inline ray_surface_t ray_render_object_point_surface(ray_render_object_point_t *point, ray_3f_t *_point)
+{
+ return point->object.surface;
+}
+
+#endif
diff --git a/src/libs/ray/ray_render_object_sphere.h b/src/libs/ray/ray_render_object_sphere.h
new file mode 100644
index 0000000..addf1f5
--- /dev/null
+++ b/src/libs/ray/ray_render_object_sphere.h
@@ -0,0 +1,90 @@
+#ifndef _RAY_RENDER_OBJECT_SPHERE_H
+#define _RAY_RENDER_OBJECT_SPHERE_H
+
+#include <math.h>
+
+#include "ray_3f.h"
+#include "ray_camera.h"
+#include "ray_color.h"
+#include "ray_object_sphere.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_render_object_sphere_t {
+ ray_object_sphere_t object;
+ ray_3f_t primary_v;
+ float primary_dot_vv;
+ float r2;
+ float r_inv;
+} ray_render_object_sphere_t;
+
+
+static ray_render_object_sphere_t ray_render_object_sphere_prepare(const ray_object_sphere_t *sphere, const ray_camera_t *camera)
+{
+ ray_render_object_sphere_t prepared = { .object = *sphere };
+
+ prepared.primary_v = ray_3f_sub(&sphere->center, &camera->position);
+ prepared.primary_dot_vv = ray_3f_dot(&prepared.primary_v, &prepared.primary_v);
+
+ prepared.r2 = sphere->radius * sphere->radius;
+
+ /* to divide by radius via multiplication in ray_object_sphere_normal() */
+ prepared.r_inv = 1.0f / sphere->radius;
+
+ return prepared;
+}
+
+
+static inline int ray_render_object_sphere_intersects_ray(ray_render_object_sphere_t *sphere, unsigned depth, ray_ray_t *ray, float *res_distance)
+{
+ ray_3f_t v = sphere->primary_v;
+ float dot_vv = sphere->primary_dot_vv;
+ float b, disc;
+
+ if (depth) {
+ v = ray_3f_sub(&sphere->object.center, &ray->origin);
+ dot_vv = ray_3f_dot(&v, &v);
+ }
+
+ b = ray_3f_dot(&v, &ray->direction);
+ disc = sphere->r2 - (dot_vv - (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_render_object_sphere_normal(ray_render_object_sphere_t *sphere, ray_3f_t *point)
+{
+ ray_3f_t normal;
+
+ normal = ray_3f_sub(point, &sphere->object.center);
+ normal = ray_3f_mult_scalar(&normal, sphere->r_inv); /* normalize without the sqrt() */
+
+ return normal;
+}
+
+
+/* return the surface of the sphere @ point */
+static inline ray_surface_t ray_render_object_sphere_surface(ray_render_object_sphere_t *sphere, ray_3f_t *point)
+{
+ /* uniform solids for now... */
+ return sphere->object.surface;
+}
+
+#endif
diff --git a/src/libs/ray/ray_scene.h b/src/libs/ray/ray_scene.h
new file mode 100644
index 0000000..ff9c440
--- /dev/null
+++ b/src/libs/ray/ray_scene.h
@@ -0,0 +1,16 @@
+#ifndef _RAY_SCENE_H
+#define _RAY_SCENE_H
+
+#include "ray_color.h"
+
+typedef union ray_object_t ray_object_t;
+
+typedef struct ray_scene_t {
+ ray_object_t *objects;
+ ray_object_t *lights;
+
+ ray_color_t ambient_color;
+ float ambient_brightness;
+} ray_scene_t;
+
+#endif
diff --git a/src/libs/ray/ray_surface.h b/src/libs/ray/ray_surface.h
new file mode 100644
index 0000000..2e7544b
--- /dev/null
+++ b/src/libs/ray/ray_surface.h
@@ -0,0 +1,15 @@
+#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 highlight_exponent;
+ float diffuse;
+} ray_surface_t;
+
+#endif
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