diff options
| -rw-r--r-- | 3dmath.c | 9 | ||||
| -rw-r--r-- | 3dmath.h | 4 | ||||
| -rw-r--r-- | ray.c | 58 |
3 files changed, 45 insertions, 26 deletions
@@ -2,8 +2,6 @@ #include <math.h> -#define POW2(x) ((x) * (x)) - float dot(const float x[3], const float y[3]) { return x[0] * y[0] + x[1] * y[1] + x[2] * y[2]; @@ -21,7 +19,7 @@ normalize(float x[3]) { float sphere_intersect(float* restrict y, float* restrict r, const float* restrict s, const float* restrict d, - const float* restrict c, float R) { + const float* restrict c, float R, int invert) { int i; float D, n[3], t, v[3]; @@ -33,7 +31,10 @@ sphere_intersect(float* restrict y, float* restrict r, if(D < 0) return -1; - t = -dot(v, d) - D; + if (invert) + t = -dot(v, d) + D; + else + t = -dot(v, d) - D; if (t <= 0) return -1; @@ -1,6 +1,8 @@ +#define POW2(x) ((x) * (x)) + float dot(const float x[3], const float y[3]); void normalize(float x[3]); float sphere_intersect(float* restrict y, float* restrict r, const float* restrict s, const float* restrict d, - const float* restrict c, float R); + const float* restrict c, float R, int invert); @@ -29,6 +29,7 @@ typedef struct { float position[3]; float radius; float diffuse[3]; + int subtract; } Object; typedef struct { @@ -47,10 +48,10 @@ static float trace_vectors[HEIGHT][WIDTH][3]; static int trace_vectors_initialized; static Object objects[] = { - {.position={-1.414, -1, -3}, .radius=1, .diffuse={.8, 0, .8}}, - {.position={0, 1.414, -3}, .radius=1, .diffuse={0, .8, .8}}, - {.position={0, 0, -3}, .radius=.25, .diffuse={.8, .8, .8}}, - {.position={1.414, -1, -3}, .radius=1, .diffuse={.8, .8, 0}} + {.position={-1.414, -1, -3}, .radius=1, .diffuse={.8, 0, .8}, .subtract=0}, + {.position={0, 1.414, -3}, .radius=1, .diffuse={0, .8, .8}, .subtract=0}, + {.position={0, 0, -3}, .radius=1.5, .diffuse={.8, .8, .8}, .subtract=1}, + {.position={1.414, -1, -3}, .radius=1, .diffuse={.8, .8, 0}, .subtract=0} }; static Light lights[] = { {.position={-3, 3, -4}, .diffuse={0, .6, .6}}, @@ -60,27 +61,42 @@ static float ambient[3] = {0.2, 0.1, 0.1}; static void trace(const float s[3], const float d[3], float pixel[3], int n, unsigned int mask) { + // Reflections in concave objects can go really deep, so we need to limit + // the recursion depth. + if (n > 6) return; + float nearest = HUGE_VAL; int nearest_object = -1; float nearest_y[3]; float nearest_r[3]; - for(int j = 0; j < LENGTH(objects); ++j) { + for(size_t j = 0; j < LENGTH(objects); ++j) { float r[3], t, y[3]; - if ((1 << j) & mask) continue; + if (((1 << j) & mask) || objects[j].subtract) continue; - t = sphere_intersect(y, r, s, d, objects[j].position, objects[j].radius); + t = sphere_intersect(y, r, s, d, objects[j].position, objects[j].radius, 0); - if(likely(t <= 0)) + if(likely(t <= 0) || t > nearest) continue; - if (t < nearest) { - nearest = t; - nearest_object = j; - memcpy(nearest_y, y, sizeof(nearest_y)); - memcpy(nearest_r, r, sizeof(nearest_y)); + size_t k; + for (k = 0; k < LENGTH(objects); ++k) { + if (!objects[k].subtract) continue; + if (POW2(y[0] - objects[k].position[0]) + POW2(y[1] - objects[k].position[1]) + POW2(y[2] - objects[k].position[2]) > POW2(objects[k].radius)) continue; + + t = sphere_intersect(y, r, s, d, objects[k].position, objects[k].radius, 1); + + break; } + + if(likely(t <= 0) || t > nearest) + continue; + + nearest = t; + nearest_object = j; + memcpy(nearest_y, y, sizeof(nearest_y)); + memcpy(nearest_r, r, sizeof(nearest_y)); } if (nearest_object == -1) return; @@ -101,7 +117,7 @@ trace(const float s[3], const float d[3], float pixel[3], int n, unsigned int ma } } - trace(nearest_y, nearest_r, pixel, n + 1, (1 << nearest_object)); + trace(nearest_y, nearest_r, pixel, n + 1, 1 << nearest_object); } static void @@ -156,13 +172,13 @@ trace_scene(float time, unsigned char *buf, int threaded) { if (!trace_vectors_initialized) initialize_trace_vectors(); - objects[0].position[0] = 1.5 * cos(time); - objects[0].position[1] = 1.5 * sin(time); - objects[1].position[0] = 1.5 * cos(time + 1/3. * TAU); - objects[1].position[1] = 1.5 * sin(time + 1/3. * TAU); - objects[3].position[0] = 1.5 * cos(time + 2/3. * TAU); - objects[3].position[1] = 1.5 * sin(time + 2/3. * TAU); - objects[2].position[2] = -3 + 2 * sin(time * 2); + objects[0].position[0] = (1.5 + 0.35 * sin(1.1 * time)) * cos(0.5 * time); + objects[0].position[1] = (1.5 + 0.35 * sin(1.1 * time)) * sin(0.5 * time); + objects[1].position[0] = (1.5 + 0.35 * sin(1.1 * time)) * cos(0.5 * time + 1/3. * TAU); + objects[1].position[1] = (1.5 + 0.35 * sin(1.1 * time)) * sin(0.5 * time + 1/3. * TAU); + objects[3].position[0] = (1.5 + 0.35 * sin(1.1 * time)) * cos(0.5 * time + 2/3. * TAU); + objects[3].position[1] = (1.5 + 0.35 * sin(1.1 * time)) * sin(0.5 * time + 2/3. * TAU); + objects[2].position[2] = -3 + 0.5 * sin(time * 2.0); if(threaded) { ThreadArg arg; |