diff options
Diffstat (limited to 'ray.c')
| -rw-r--r-- | ray.c | 103 |
1 files changed, 62 insertions, 41 deletions
@@ -131,11 +131,63 @@ object_t *ray_cast(space_t *s, ray_t *r, COORD_T *dist_ret, bool chk, COORD_T ch return smallest; } -static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vector_t *eye, vector_t *point) +// Light (l) the object o reflects. Given is the point of intersect, vector to the light l, vector to viewer V, and normal at point N. +static void reflected_at(object_t *o, color_t *dest, light_t *light, COORD_T dist, vector_t *point, vector_t *l, vector_t *V, vector_t *N) { + // Calculate light intensity + COORD_T i = light->radiance / ( dist * dist); + + // Calculate Deffuse part + color_t tmp; + COORD_T cl = vector_dot(l, N) * i; + if (cl > 0) { + color_scale(&tmp, &light->color, cl * o->m->defuse); + color_add(dest, &tmp, dest); + } + + // calculate specular part. TODO implement blinn-phong + // Calculate R_m + vector_t R; + vector_scale(&R, N, 2 * vector_dot(l, N)); + vector_sub(&R, &R, l); + + // Add it to the light + cl = vector_dot(&R, V) * i; + if (cl > 0) { + cl = pow(cl, o->m->shine); + color_scale(&tmp, &light->color, cl * o->m->specular); + color_add(dest, &tmp, dest); + } +} + +// Calculate the contribution of light on o. V is vector to viewer and N is normal at point +static void contribution_from_pointlight(space_t *s, color_t *dest, object_t *o, light_t *light, vector_t *point, vector_t *V, vector_t *N) { + vector_t l; + + // Prepare ray ray_t r; r.start = point; - + + // Calculate distance to light + vector_sub(&l, &light->point.pos, point); + COORD_T d = vector_len(&l); + + // Normalice + vector_scale_inv(&l, &l, vector_len(&l)); + + // Find obstacles + r.direction = &l; + object_t *obs = ray_cast(s, &r, NULL, true, d); + if (obs) { + return; + } + + // Calculate the reflected light + reflected_at(o, dest, light, d, point, &l, V, N); +} + +static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vector_t *eye, vector_t *point) +{ // And vector towards viewer vector_t V; vector_sub(&V, eye, point); @@ -143,47 +195,11 @@ static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, ve // Normalice it vector_scale_inv(&V, &V, vector_len(&V)); - // Cast light rays + // Loop lights light_t *light = s->lights; while (light) { - vector_t l; - - // Calculate distance to light - vector_sub(&l, &light->pos, point); - COORD_T d = vector_len(&l); - - // Normalice - vector_scale_inv(&l, &l, vector_len(&l)); - - // Find obstacles - r.direction = &l; - object_t *obs = ray_cast(s, &r, NULL, true, d); - if (obs) { - light = light->next; - continue; - } - - // Calculate Deffuse part - color_t tmp; - COORD_T cl = vector_dot(&l, N); - if (cl > 0) { - color_scale(&tmp, &light->defuse, cl * o->m->defuse); - color_add(dest, &tmp, dest); - } - - // calculate specular part. TODO implement blinn-phong - // Calculate R_m - vector_t R; - vector_scale(&R, N, 2 * vector_dot(&l, N)); - vector_sub(&R, &R, &l); - - // Add it to the light - cl = 1 * vector_dot(&R, &V); - if (cl > 0) { - cl = pow(cl, o->m->shine); - color_scale(&tmp, &light->specular, cl * o->m->specular); - color_add(dest, &tmp, dest); - } + // Calculate contribution depending on the light type + contribution_from_pointlight(s, dest, o, light, point, &V, N); light = light->next; } @@ -278,6 +294,11 @@ int ray_trace_recur(space_t *s, color_t *dest, ray_t *ray, unsigned hop, COORD_T vector_t N; obj_norm_at(o, &N, r.start, ray->direction); + // Check if emissive + if (o->m->emissive > ZERO_APROX) { + color_set(&c, o->m->emissive, o->m->emissive, o->m->emissive); + } + // Check if we should calculate light if (o->m->defuse + o->m->specular > ZERO_APROX) { // Add all light hitting o at r.start to c |