first pass at bvh construction (SAH), untested

[cyberay] / src / rt.c

diff --git a/src/rt.c b/src/rt.c
index 2c6ceaf..020c51f 100644 (file)
--- a/src/rt.c
+++ b/src/rt.c
@@ -1,37 +1,128 @@
+#include <float.h>
 #include "rt.h"
+#include "game.h"
+
+#define TILESZ 32
+
+struct tile {
+       int x, y, width, height;
+       int sample;
+       cgm_vec3 *fbptr;
+};
 
 struct framebuffer fb;
+struct thread_pool *tpool;
+float view_xform[16];
+float vfov = M_PI / 4;
+
+static float aspect;
+static struct tile *tiles;
+static int num_tiles;
+
+static void render_tile(struct tile *tile);
+static void ray_trace(cgm_vec3 *color, cgm_ray *ray);
+static void bgcolor(cgm_vec3 *color, cgm_ray *ray);
+static void primary_ray(cgm_ray *ray, int x, int y, int sample);
 
 int fbsize(int width, int height)
 {
-       void *tmp;
+       int i, j, x, y, xtiles, ytiles;
+       cgm_vec3 *fbptr;
+       struct tile *tileptr;
 
-       if(!(tmp = malloc(width * height * sizeof *fb.pixels))) {
+       if(!(fbptr = malloc(width * height * sizeof *fb.pixels))) {
+               return -1;
+       }
+       xtiles = (width + TILESZ - 1) / TILESZ;
+       ytiles = (height + TILESZ - 1) / TILESZ;
+       if(!(tileptr = malloc(xtiles * ytiles * sizeof *tiles))) {
+               free(fbptr);
                return -1;
        }
 
        free(fb.pixels);
-       fb.pixels = tmp;
+       fb.pixels = fbptr;
        fb.width = width;
        fb.height = height;
+
+       free(tiles);
+       tiles = tileptr;
+       num_tiles = xtiles * ytiles;
+
+       aspect = (float)fb.width / (float)fb.height;
+
+       y = 0;
+       for(i=0; i<ytiles; i++) {
+               x = 0;
+               for(j=0; j<xtiles; j++) {
+                       tileptr->x = x;
+                       tileptr->y = y;
+                       tileptr->width = width - x < TILESZ ? width - x : TILESZ;
+                       tileptr->height = height - y < TILESZ ? height - y : TILESZ;
+                       tileptr->fbptr = fbptr + x;
+                       tileptr++;
+
+                       x += TILESZ;
+               }
+               fbptr += width * TILESZ;
+               y += TILESZ;
+       }
+
        return 0;
 }
 
 void render(void)
 {
+       int i;
+
+       for(i=0; i<num_tiles; i++) {
+               tpool_enqueue(tpool, tiles + i, (tpool_callback)render_tile, 0);
+       }
+       tpool_wait(tpool);
+}
+
+static void render_tile(struct tile *tile)
+{
        int i, j;
-       cgm_vec3 *fbptr = fb.pixels;
-
-       for(i=0; i<fb.height; i++) {
-               for(j=0; j<fb.width; j++) {
-                       if(i < 3 || i >= fb.height - 3 || j < 3 || j >= fb.width - 3) {
-                               fbptr->x = 1.0f;
-                               fbptr->y = fbptr->z = 0.0f;
-                       } else {
-                               fbptr->x = fbptr->z = 0.0f;
-                               fbptr->y = 1.0f;
-                       }
-                       fbptr++;
+       cgm_ray ray;
+       cgm_vec3 *fbptr = tile->fbptr;
+
+       for(i=0; i<tile->height; i++) {
+               for(j=0; j<tile->width; j++) {
+                       primary_ray(&ray, tile->x + j, tile->y + i, tile->sample);
+                       ray_trace(fbptr + j, &ray);
                }
+               fbptr += fb.width;
+       }
+}
+
+static void ray_trace(cgm_vec3 *color, cgm_ray *ray)
+{
+       struct rayhit hit;
+
+       if(ray_level(ray, &lvl, FLT_MAX, &hit)) {
+               color->x = hit.v.norm.x * 0.5 + 0.5;
+               color->y = hit.v.norm.y * 0.5 + 0.5;
+               color->z = hit.v.norm.z * 0.5 + 0.5;
+       } else {
+               bgcolor(color, ray);
        }
 }
+
+static void bgcolor(cgm_vec3 *color, cgm_ray *ray)
+{
+       color->x = color->y = color->z = 1.0f;
+}
+
+static void primary_ray(cgm_ray *ray, int x, int y, int sample)
+{
+       ray->origin.x = ray->origin.y = ray->origin.z = 0.0f;
+       ray->dir.x = (2.0f * (float)x / (float)fb.width - 1.0f) * aspect;
+       ray->dir.y = 1.0f - 2.0f * (float)y / (float)fb.height;
+       ray->dir.z = -1.0f / tan(vfov / 2.0f);
+       cgm_vnormalize(&ray->dir);
+
+       /* TODO jitter */
+
+       cgm_rmul_mr(ray, view_xform);
+}