Pretty realistic colors

6 files changed, 108 insertions, 23 deletions

diff --git a/main.c b/main.c
index 011f2c1..0f0103a 100644
--- a/main.c
+++ b/main.c
@@ -19,6 +19,9 @@ int main()
 	s.objects = NULL;
 	s.lights = NULL;
 
+	material_t m;
+	vector_set(&m.color, 0, 1, 0);
+
 	vector_set(&s.view.position, 0, 15, 10);
 	vector_set(&s.view.target, 0, 0, 0);
 	s.view.width = TESTW;
@@ -27,8 +30,8 @@ int main()
 	viewpoint_init(&s.view);
 	
 	// Setup plane
-	add_sphere(&s, vector_set(NULL, 0, 0, 5), 5);
-	add_sphere(&s, vector_set(NULL, 10, 0, 5), 5);
+	add_sphere(&s, vector_set(NULL, 0, 0, 5), 5, &m);
+	//add_sphere(&s, vector_set(NULL, 10, 0, 5), 5);
 	add_plane(&s, vector_set(NULL, 0, 0, 2), vector_set(NULL, 0, 0, 1));
 	add_light(&s, vector_set(NULL, 10, 0, 20), color_set(NULL, 255, 255, 255));
 
diff --git a/pgm.c b/pgm.c
index 058b445..90791de 100644
--- a/pgm.c
+++ b/pgm.c
@@ -25,3 +25,42 @@ color_t *color_set(color_t *c, uint8_t r, uint8_t g, uint8_t b)
 
 	return c;
 }
+
+color_t *color_add(color_t *dest, color_t *a, color_t *b)
+{
+	if (!dest) {
+		dest = (color_t *) malloc(sizeof(dest));
+	}
+
+	dest->r = a->r + b->r;
+	dest->g = a->g + b->g;
+	dest->b = a->b + b->b;
+
+	return dest;
+}
+
+color_t *color_scale(color_t *dest, color_t *a, float b)
+{
+	if (!dest) {
+		dest = (color_t *) malloc(sizeof(dest));
+	}
+
+	dest->r = a->r * b;
+	dest->g = a->g * b;
+	dest->b = a->b * b;
+
+	return dest;
+}
+
+color_t *color_scale_vector(color_t *dest, color_t *a, vector_t *v)
+{
+	if (!dest) {
+		dest = (color_t *) malloc(sizeof(dest));
+	}
+
+	dest->r = a->r * v->x;
+	dest->g = a->g * v->y;
+	dest->b = a->b * v->z;
+
+	return dest;
+}
diff --git a/pgm.h b/pgm.h
index b8900b8..3e40034 100644
--- a/pgm.h
+++ b/pgm.h
@@ -3,12 +3,16 @@
 
 #include <stdio.h>
 #include <stdint.h>
+#include "vector.h"
 
 typedef struct {
 	uint8_t r, g, b;
 } color_t;
 
 color_t *color_set(color_t *c, uint8_t r, uint8_t g, uint8_t b);
+color_t *color_scale(color_t *dest, color_t *a, float b);
+color_t *color_add(color_t *dest, color_t *a, color_t *b);
+color_t *color_scale_vector(color_t *dest, color_t *a, vector_t *v);
 
 int pgm_write_header(FILE *fp, unsigned int w, unsigned int h);
 int pgm_write_pixel(FILE *fp, color_t *c);
diff --git a/ray.c b/ray.c
index 3736773..0e82546 100644
--- a/ray.c
+++ b/ray.c
@@ -142,33 +142,46 @@ color_t *ray_trace(space_t *s, unsigned int x, unsigned int y)
 	if (!o) {
 		return NULL;
 	}
-	//printf("dist: %f\n", dist);
 
 	// Calculate new ray point
 	r.start = vector_scale(NULL, r.direction, dist);
 	vector_add(r.start, r.start, &s->view.position);
 
+	// Calculate normal vector
+	vector_t n;
+	obj_norm_at(o, &n, r.start);
+
+	// Hit color
+	color_t *c = color_set(NULL, 0, 0, 0);
+
 	// Cast light rays
-	light_t *l = s->lights;
-	while (l) {
-		vector_t tmp;
+	light_t *light = s->lights;
+	while (light) {
+		vector_t l;
 		// Calculate distance to light
-		vector_sub(&tmp, l->pos, r.start);
-		COORD_T d = vector_len(&tmp);
-		
-		// Calculate unit
-		vector_scale_inv(&tmp, &tmp, vector_len(&tmp));
+		vector_sub(&l, light->pos, r.start);
+		COORD_T d = vector_len(&l);
 
 		// Find obstacles
-		r.direction = &tmp;
+		r.direction = &l;
 		object_t *obs = ray_cast(s, &r, NULL, true, d);
-
-		if (!obs) {
-			return color_set(NULL, 100, 100, o->type == TYPE_SPHERE ? 200 :0);
+		if (obs) {
+			light = light->next;
+			continue;
 		}
+		
+		// Calculate unit
+		vector_scale_inv(&l, &l, vector_len(&l));
+		color_t tmp;
+		color_scale(&tmp, light->defuse, vector_dot(&l, &n));
+		color_add(c, &tmp, c);
 			
-		l = l->next;
+		light = light->next;
+	}
+
+	if (o->m) {
+		color_scale_vector(c, c, &o->m->color);
 	}
 
-	return NULL;
+	return c;
 }
diff --git a/scene.c b/scene.c
index a75b329..99ae0e8 100644
--- a/scene.c
+++ b/scene.c
@@ -12,11 +12,13 @@ static inline void link_object(space_t *s, object_t *o)
 	}
 }
 
-object_t *add_sphere(space_t *s, vector_t *c, COORD_T r)
+object_t *add_sphere(space_t *s, vector_t *c, COORD_T r, material_t *m)
 {
 	object_t *o = (object_t *) malloc(sizeof(object_t));
 
 	o->type = TYPE_SPHERE;
+	o->m = m;
+
 	o->sph.center = c;
 	o->sph.radius = r;
 
@@ -38,12 +40,12 @@ object_t *add_plane(space_t *s, vector_t *start, vector_t *dir)
 	return o;
 }
 
-light_t *add_light(space_t *s, vector_t *pos, color_t *c)
+light_t *add_light(space_t *s, vector_t *pos, color_t *defuse)
 {
 	light_t *o = (light_t *) malloc(sizeof(light_t));
 
 	o->pos = pos;
-	o->col = c;
+	o->defuse = defuse;
 
 	if (s) {
 		o->next = s->lights;
@@ -54,3 +56,18 @@ light_t *add_light(space_t *s, vector_t *pos, color_t *c)
 
 	return o;
 }
+
+void obj_norm_at(object_t *o, vector_t *dest, vector_t *point)
+{
+	switch(o->type) {
+		case TYPE_SPHERE:
+			vector_sub(dest, point, o->sph.center);
+			vector_scale_inv(dest, dest, vector_len(dest));
+			break;
+		case TYPE_PLANE:
+			vector_copy(dest, o->pl.norm);
+			break;
+	}
+
+	return;
+}
diff --git a/scene.h b/scene.h
index 1c6363b..7efb5cd 100644
--- a/scene.h
+++ b/scene.h
@@ -23,16 +23,23 @@ typedef struct {
 
 typedef struct light_s{
 	vector_t *pos;
-	color_t *col;
+	color_t *defuse;
 
 	struct light_s *next;
 } light_t;
 
+typedef struct {
+	vector_t color;
+} material_t;
+
 // General object structure
 typedef struct object_s{
 	uint8_t type;
 	struct object_s *next;
 
+	// Color and light information
+	material_t *m;
+
 	union {
 		sphere_t sph;
 		plane_t pl;
@@ -45,8 +52,10 @@ typedef struct {
 	light_t *lights;
 } space_t;
 
-object_t *add_sphere(space_t *s, vector_t *c, COORD_T r);
+object_t *add_sphere(space_t *s, vector_t *c, COORD_T r, material_t *m);
 object_t *add_plane(space_t *s, vector_t *start, vector_t *dir);
-light_t *add_light(space_t *s, vector_t *pos, color_t *c);
+light_t *add_light(space_t *s, vector_t *pos, color_t *defuse);
+
+void obj_norm_at(object_t *o, vector_t *dest, vector_t *point);
 
 #endif