diff options
| -rw-r--r-- | main.c | 206 | ||||
| -rw-r--r-- | vector.c | 2 |
2 files changed, 103 insertions, 105 deletions
@@ -9,19 +9,21 @@ #include <SDL/SDL.h> #include <SDL/SDL_video.h> -#define WIDTH 40 -#define HEIGHT 30 +#define WIDTH 320 +#define HEIGHT 240 #define MAX(a, b) ((a>b)?(a):(b)) #define MIN(a, b) ((a<b)?(a):(b)) #define SQR(a) ((a)*(a)) #define SIGN(x) ((x)<0?-1:1) -#define MAX_BOUNCES 200 +#define MAX_BOUNCES 50 #define MIN_BOUNCES 2 #define MOVE_FACTOR .15 #define TARGET_MS 50 +#define N_LIGHTS 1 + #define PPMOUT #define MOUSELOOK @@ -33,7 +35,7 @@ struct object_t { union { struct { vector center; scalar radius; } sphere; struct { vector point, normal; } plane; - struct { vector points[3]; } tri; + struct { vector points[3], normal, u, v; scalar uu, uv, vv, dn; } tri; }; struct rgb_t color; int specularity; /* 0-255 */ @@ -54,17 +56,32 @@ struct scene_t { }; struct camera_t { - vector origin; - vector direction; /* direction to center of camera */ + vector origin; /* position */ + vector direction; scalar fov_x, fov_y; /* radians */ }; +void preprocess_object(struct object_t *obj) +{ + switch(obj->type) + { + case TRI: + obj->tri.u = vect_sub(obj->tri.points[1], obj->tri.points[0]); + obj->tri.v = vect_sub(obj->tri.points[2], obj->tri.points[0]); + obj->tri.normal = vect_cross(obj->tri.u, obj->tri.v); + obj->tri.uu = vect_dot(obj->tri.u, obj->tri.u); + obj->tri.uv = vect_dot(obj->tri.u, obj->tri.v); + obj->tri.vv = vect_dot(obj->tri.v, obj->tri.v); + obj->tri.dn = SQR(obj->tri.uv) - obj->tri.uu * obj->tri.vv; + break; + } +} + /* { o, d } form a ray */ /* point of intersection is *t * d units away */ inline bool object_intersects(const struct object_t *obj, vector o, vector d, scalar *t) { assert(o.type == RECT); - vect_to_rect(&d); assert(d.type == RECT); switch(obj->type) { @@ -117,22 +134,19 @@ inline bool object_intersects(const struct object_t *obj, vector o, vector d, sc } case TRI: { - vector u = vect_sub(obj->tri.points[1], obj->tri.points[0]); - vector v = vect_sub(obj->tri.points[2], obj->tri.points[0]); - vector normal = vect_cross(u, v); - if(vect_abs(normal) == 0) + if(vect_abs(obj->tri.normal) == 0) { //printf("degenerate triangle\n"); return false; } - scalar denom = vect_dot(normal, d); + scalar denom = vect_dot(obj->tri.normal, d); /* doesn't intersect plane of triangle */ if(!denom) { //printf("parallel\n"); return false; } - scalar t1 = vect_dot(normal, vect_sub(obj->tri.points[0], o)) / denom; + scalar t1 = vect_dot(obj->tri.normal, vect_sub(obj->tri.points[0], o)) / denom; /* behind camera */ if(t1 <= 0) { @@ -142,21 +156,17 @@ inline bool object_intersects(const struct object_t *obj, vector o, vector d, sc vector pt = vect_add(vect_mul(d, t1), o); vect_to_rect(&pt); - scalar uu, uv, vv, wu, wv; - uu = vect_dot(u, u); - uv = vect_dot(u, v); - vv = vect_dot(v, v); + scalar wu, wv; vector w = vect_sub(pt, obj->tri.points[0]); - wu = vect_dot(w, u); - wv = vect_dot(w, v); - denom = SQR(uv) - uu * vv; - scalar s1 = (uv * wv - vv * wu) / denom; + wu = vect_dot(w, obj->tri.u); + wv = vect_dot(w, obj->tri.v); + scalar s1 = (obj->tri.uv * wv - obj->tri.vv * wu) / obj->tri.dn; if(s1 < 0. || s1 > 1.) { //printf("not inside\n"); return false; } - scalar s2 = (uv * wu - uu * wv) / denom; + scalar s2 = (obj->tri.uv * wu - obj->tri.uu * wv) / obj->tri.dn; if(s2 < 0. || (s1 + s2) > 1.) { //printf("not inside\n"); @@ -180,8 +190,7 @@ vector normal_at_point(vector pt, const struct object_t *obj) normal = obj->plane.normal; break; case TRI: - normal = vect_cross(vect_sub(obj->tri.points[1], obj->tri.points[2]), - vect_sub(obj->tri.points[3], obj->tri.points[2])); + normal = vect_negate(obj->tri.normal); break; default: assert(false); @@ -284,7 +293,7 @@ struct rgb_t trace_ray(const struct scene_t *scene, vector orig, vector d, int m scalar shade = vect_dot(normal, light_dir); if(shade > 0) - shade_total += shade * scene->lights[i].intensity * 1 / (SQR(light_dist)); + shade_total += shade * scene->lights[i].intensity * 1 / SQR(light_dist); } if(shade_total > 1) @@ -297,24 +306,44 @@ struct rgb_t trace_ray(const struct scene_t *scene, vector orig, vector d, int m vector ref = reflect_ray(pt, d, normal, hit_obj); reflected = trace_ray(scene, pt, ref, max_iters - 1, hit_obj); } + + scalar diffuse = 1 - scene->ambient; + primary.r *= (scene->ambient + diffuse * shade_total); + primary.g *= (scene->ambient + diffuse * shade_total); + primary.b *= (scene->ambient + diffuse * shade_total); } struct rgb_t mixed = blend(primary, reflected, specular); - scalar diffuse = 1 - scene->ambient; - mixed.r *= (scene->ambient + diffuse * shade_total); - mixed.g *= (scene->ambient + diffuse * shade_total); - mixed.b *= (scene->ambient + diffuse * shade_total); return mixed; } +vector ray_to_pixel(vector origin, vector direction, int x, int y, int w, int h, const struct camera_t *cam) +{ + scalar scale_x = tan(.5 * cam->fov_x / w), scale_y = tan(.5 * cam->fov_y / h); + + /* rot in range of [-fov / 2, fov / 2) */ + scalar rot_x = (x - w / 2) * scale_x, rot_y = (y - h / 2) * scale_y; + + /* rotate the offset vector */ + + vector d = direction; + assert(d.type == SPH); + + d.sph.elevation -= rot_y; + d.sph.azimuth += rot_x; + + vect_to_rect(&d); + return d; +} + void render_lines(unsigned char *fb, int w, int h, const struct scene_t *scene, const struct camera_t *cam, int start, int end, int bounces, int worker) { - scalar scale_x = cam->fov_x / w, scale_y = cam->fov_y / h; + scalar scale_x = tan(.5 * cam->fov_x / w), scale_y = tan(.5 * cam->fov_y / h); vector direction = cam->direction; vect_to_sph(&direction); @@ -330,15 +359,7 @@ void render_lines(unsigned char *fb, int w, int h, /* rot in range of [-fov / 2, fov / 2) */ scalar rot_x = (x - w / 2) * scale_x, rot_y = (y - h / 2) * scale_y; - /* rotate the offset vector */ - - vector d = direction; - d.sph.elevation -= rot_y; - d.sph.azimuth += rot_x; - - vect_to_rect(&d); - - //printf("(%d, %d) maps to (%f, %f, %f)\n", x, y, d.rect.x, d.rect.y, d.rect.z); + vector d = ray_to_pixel(cam->origin, direction, x, y, w, h, cam); /* cam->origin and d now form the camera ray */ @@ -356,7 +377,7 @@ void render_lines(unsigned char *fb, int w, int h, } #ifdef PPMOUT - printf("Worker %d: %d%% (%d/%d)\n", worker, 100 * y / h, y, h); + printf("Worker %d: %d%% (%d/%d)\n", worker, 100 * (y+1) / h, y+1, h); #endif } } @@ -409,113 +430,83 @@ scalar rand_norm(void) return rand() / (scalar)RAND_MAX; } +void preprocess_scene(const struct scene_t *scene) +{ + for(int i = 0; i < scene->n_objects; ++i) + { + preprocess_object(scene->objects + i); + } +} + int main() { struct scene_t scene; scene.bg.r = 0x87; scene.bg.g = 0xce; scene.bg.b = 0xeb; - scene.ambient = .5; + scene.ambient = .2; struct object_t sph[8]; #if 1 sph[0].type = SPHERE; - sph[0].sphere.center = (vector) { RECT, {0, 1, 1 } }; + sph[0].sphere.center = (vector) { RECT, {1, 1, 0 } }; sph[0].sphere.radius = 1; sph[0].color = (struct rgb_t){0, 0, 0xff}; sph[0].specularity = 0xf0; sph[1].type = SPHERE; - sph[1].sphere.center = (vector) { RECT, {0, 1, -1 } }; + sph[1].sphere.center = (vector) { RECT, {-1, 1, 0 } }; sph[1].sphere.radius = 1; sph[1].color = (struct rgb_t){0xff, 0, 0}; sph[1].specularity = 40; sph[2].type = SPHERE; - sph[2].sphere.center = (vector) { RECT, {0, 1, -3 } }; + sph[2].sphere.center = (vector) { RECT, {-3, 1, 0 } }; sph[2].sphere.radius = 1; sph[2].color = (struct rgb_t){0xff, 0xff, 0xff}; sph[2].specularity = 0xf0; sph[3].type = PLANE; - sph[3].plane.point = (vector) { RECT, {0, 0, 100 } }; + sph[3].plane.point = (vector) { RECT, {0, 0, 0 } }; sph[3].plane.normal = (vector) { RECT, {0, 1, 0 } }; sph[3].color = (struct rgb_t) {0, 0xff, 0}; sph[3].specularity = 0; #endif sph[4].type = TRI; - sph[4].tri.points[0] = (vector) { RECT, {0, 0, 0 } }; - sph[4].tri.points[1] = (vector) { RECT, {0, 5, 0 } }; - sph[4].tri.points[2] = (vector) { RECT, {0, 0, 5 } }; - sph[4].color = (struct rgb_t) {0xff, 0, 0xff}; - sph[4].specularity = 0; - - sph[5].type = TRI; - sph[5].tri.points[0] = (vector) { RECT, {0, 5, 5 } }; - sph[5].tri.points[1] = (vector) { RECT, {0, 5, 0 } }; - sph[5].tri.points[2] = (vector) { RECT, {0, 0, 5 } }; - sph[5].color = (struct rgb_t) {0xff, 0, 0xff}; - sph[5].specularity = 0; - - sph[6].type = TRI; - sph[6].tri.points[0] = (vector) { RECT, {10, 0, -5 } }; - sph[6].tri.points[1] = (vector) { RECT, {5, 5, 0 } }; - sph[6].tri.points[2] = (vector) { RECT, {0, 0, -5 } }; - sph[6].color = (struct rgb_t) {0xff, 0, 0xff}; - sph[6].specularity = 0xe0; -#if 0 - sph[4].type = PLANE; - sph[4].plane.point = (vector) { RECT, {10, 0, 0 } }; - sph[4].plane.normal = (vector) { RECT, {-1, 0, 0 } }; - sph[4].color = (struct rgb_t) {224, 223, 91}; - sph[4].specularity = 0xf0; - - sph[5].type = PLANE; - sph[5].plane.point = (vector) { RECT, {-10, 0, 0 } }; - sph[5].plane.normal = (vector) { RECT, {1, 0, 0 } }; - sph[5].color = (struct rgb_t) {224, 223, 91}; - sph[5].specularity = 0xf0; - - - sph[4].type = PLANE; - sph[4].plane.point = (vector) { RECT, {0, 0, -10 } }; - sph[4].plane.normal = (vector) { RECT, {0, 0, 1 } }; - sph[4].color = (struct rgb_t) {224, 223, 91}; - sph[4].specularity = 0xf0; - - sph[5].type = PLANE; - sph[5].plane.point = (vector) { RECT, {0, 0, 10 } }; - sph[5].plane.normal = (vector) { RECT, {0, 0, -1 } }; - sph[5].color = (struct rgb_t) {224, 223, 91}; - sph[5].specularity = 0xf0; -#endif + sph[4].tri.points[0] = (vector) { RECT, {5, 0, 0 } }; + sph[4].tri.points[1] = (vector) { RECT, {5, 5, 0 } }; + sph[4].tri.points[2] = (vector) { RECT, {0, 5, 0 } }; + sph[4].color = (struct rgb_t) {0xff, 0, 0}; + sph[4].specularity = 0x30; /* distribute evenly in a sphere of r = 1 */ - struct light_t lights[50]; - for(int i = 0; i < 50; ++i) + struct light_t lights[N_LIGHTS]; + for(int i = 0; i < N_LIGHTS; ++i) { - lights[i].position = vect_add((vector) { RECT, {5, 10, 0} }, + lights[i].position = vect_add((vector) { RECT, {5, 10, -5} }, (vector) { SPH, { .sph.r = rand_norm(), .sph.elevation = 2 * M_PI * (rand_norm() - .5), .sph.azimuth = 4 * M_PI * (rand_norm() - .5) } } ); - lights[i].intensity = 4; + lights[i].intensity = 200 / N_LIGHTS; } scene.objects = sph; - scene.n_objects = 7; + scene.n_objects = 5; scene.lights = lights; - scene.n_lights = 50; + scene.n_lights = N_LIGHTS; struct camera_t cam; - cam.origin = (vector){ RECT, {-5, 2, -1} }; - cam.direction = (vector){ RECT, {0, 0, 1} }; - cam.fov_x = M_PI / 2; - cam.fov_y = M_PI / 2 * HEIGHT / WIDTH; + cam.origin = (vector){ RECT, {0, 1, -5} }; + cam.direction = (vector){ RECT, {1, 0, 0} }; + cam.fov_x = M_PI; + cam.fov_y = M_PI * HEIGHT / WIDTH; unsigned char *fb = malloc(WIDTH * HEIGHT * 3); + preprocess_scene(&scene); + #ifdef PPMOUT render_scene(fb, WIDTH, HEIGHT, &scene, &cam, 2, MAX_BOUNCES); FILE *f = fopen("test.ppm", "w"); @@ -537,7 +528,6 @@ int main() while(1) { - //lights[0].position.rect.z += .05; #ifdef MOUSELOOK /* mouse look */ int x, y; @@ -547,6 +537,17 @@ int main() vect_to_sph(&cam.direction); cam.direction.sph.azimuth += M_PI/10 * SIGN(x)*SQR((scalar)x / WIDTH); cam.direction.sph.elevation += M_PI/10 * SIGN(y)*SQR((scalar)y / HEIGHT); + if(mouse & SDL_BUTTON(1)) + { + vector d = ray_to_pixel(cam.origin, cam.direction, x + WIDTH/2, y + HEIGHT/2, WIDTH, HEIGHT, &cam); + scalar dist; + struct object_t *obj = scene_intersections(&scene, cam.origin, d, &dist, NULL); + if(obj) + { + obj->color = (struct rgb_t) { 0xff, 0, 0xff }; + printf("Clicked object at %d, %d\n", x, y); + } + } #endif render_scene(fb, WIDTH, HEIGHT, &scene, &cam, 2, bounces); @@ -570,9 +571,6 @@ int main() bounces = MIN_BOUNCES; } - - printf("%d bounces\n", bounces); - ts = now; SDL_Event e; @@ -41,7 +41,7 @@ scalar vect_abs(vector v) switch(v.type) { case SPH: - return v.sph.r; + return fabs(v.sph.r); case RECT: return sqrt(v.rect.x * v.rect.x + v.rect.y * v.rect.y + v.rect.z * v.rect.z); } |