Added phong light model and fixed sphere intersect

6 files changed, 119 insertions, 32 deletions

diff --git a/main.c b/main.c
index 0f0103a..d7232e0 100644
--- a/main.c
+++ b/main.c
@@ -11,6 +11,7 @@
 #define TESTH 1000
 
 color_t back = {0, 0, 0};
+int print = 0;
 
 int main()
 {
@@ -18,11 +19,21 @@ int main()
 	space_t s;
 	s.objects = NULL;
 	s.lights = NULL;
+	color_set(&s.ambient, 30, 30, 30);
 
 	material_t m;
 	vector_set(&m.color, 0, 1, 0);
+	m.defuse = 1;
+	m.specular = 0.7;
+	m.shine = 20;
 
-	vector_set(&s.view.position, 0, 15, 10);
+	material_t mpl;
+	vector_set(&mpl.color, 0, 0.396, 0.7019);
+	mpl.defuse = 1;
+	mpl.specular = 0.3;
+	mpl.shine = 20;
+
+	vector_set(&s.view.position, 0, 15, 8);
 	vector_set(&s.view.target, 0, 0, 0);
 	s.view.width = TESTW;
 	s.view.height = TESTH;
@@ -30,14 +41,19 @@ int main()
 	viewpoint_init(&s.view);
 	
 	// Setup plane
-	add_sphere(&s, vector_set(NULL, 0, 0, 5), 5, &m);
+	add_sphere(&s, vector_set(NULL, 3, 0, 5), 5, &m);
+	add_sphere(&s, vector_set(NULL, -6, -3, 7), 3, &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));
+	add_plane(&s, vector_set(NULL, 0, 0, 2), vector_set(NULL, 0, 0, 1), &mpl);
+	add_light(&s, vector_set(NULL, 10, 0, 20), color_set(NULL, 150, 150, 150), color_set(NULL, 150, 150, 150));
 
 	pgm_write_header(stdout, TESTW, TESTH);
 	for (int y = TESTH; y; y--) {
 		for (int x = TESTW; x; x--) {
+			if (0 && y <= 500) {
+				printf("Lets go");
+				print = 1;
+			}
 			color_t *c = ray_trace(&s, x, y);
 
 			if (c) {
@@ -46,6 +62,7 @@ int main()
 				pgm_write_pixel(stdout, &back);
 			}
 			free(c);
+			print = 0;
 		}
 	}
 	
diff --git a/pgm.c b/pgm.c
index 90791de..efc50f7 100644
--- a/pgm.c
+++ b/pgm.c
@@ -32,9 +32,14 @@ color_t *color_add(color_t *dest, color_t *a, color_t *b)
 		dest = (color_t *) malloc(sizeof(dest));
 	}
 
-	dest->r = a->r + b->r;
-	dest->g = a->g + b->g;
-	dest->b = a->b + b->b;
+	unsigned int tmp = a->r + b->r;
+	dest->r = tmp > 255 ? 255 : tmp;
+
+	tmp = a->g + b->g;
+	dest->g = tmp > 255 ? 255 : tmp;
+
+	tmp = a->b + b->b;
+	dest->b = tmp > 255 ? 255 : tmp;
 
 	return dest;
 }
@@ -45,9 +50,14 @@ color_t *color_scale(color_t *dest, color_t *a, float b)
 		dest = (color_t *) malloc(sizeof(dest));
 	}
 
-	dest->r = a->r * b;
-	dest->g = a->g * b;
-	dest->b = a->b * b;
+	unsigned int tmp = a->r * b;
+	dest->r = tmp > 255 ? 255 : tmp;
+
+	tmp = a->g * b;
+	dest->g = tmp > 255 ? 255 : tmp;
+
+	tmp = a->b * b;
+	dest->b = tmp > 255 ? 255 : tmp;
 
 	return dest;
 }
diff --git a/ray.c b/ray.c
index 0e82546..d5b6a89 100644
--- a/ray.c
+++ b/ray.c
@@ -4,6 +4,8 @@
 
 #include "ray.h"
 
+extern int print;
+
 // https://en.wikipedia.org/wiki/Line%E2%80%93sphere_intersection
 // http://viclw17.github.io/2018/07/16/raytracing-ray-sphere-intersection/
 // https://www.scratchapixel.com/lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ray-sphere-intersection
@@ -26,6 +28,9 @@ COORD_T ray_intersect_sphere(sphere_t *s, ray_t *ray, bool skip_dist)
         return -1;
     }
 	if (skip_dist) {
+		if (print) {
+			printf("sph dist: skip\n");
+		}
 		return 1;
 	}
 
@@ -34,11 +39,11 @@ COORD_T ray_intersect_sphere(sphere_t *s, ray_t *ray, bool skip_dist)
 		-0.5 * (b + sqrt(d)) :
 		-0.5 * (b - sqrt(d));
 
-	COORD_T x0 = q / a;
-	COORD_T x1 = c / q;
+	COORD_T x1 = q / a;
+	COORD_T x0 = c / q;
 
 	// Take the correct result. If one is zero take the other.
-	if (x0 <= 0) {
+	if (x0 <= ZERO_APROX) {
 		if (x1 <= 0) {
 			return -1;
 		}
@@ -47,9 +52,12 @@ COORD_T ray_intersect_sphere(sphere_t *s, ray_t *ray, bool skip_dist)
 	}
 
 	// If point is on sphere it will be zero close to zero
-	if (x0 < 1e-3) {
+	if (x0 < ZERO_APROX) {
 		return -1;
 	}
+	if (print) {
+		printf("sph dist: %f\n", x0);
+	}
 
 	return x0;
 }
@@ -60,12 +68,18 @@ COORD_T ray_intersect_plane(plane_t *p, ray_t *ray, bool skip_dist)
 {
 	// If zero ray is parralel to plane
 	COORD_T nr = vector_dot(p->norm, ray->direction);
-	//
+	
 	// Take care of rounding errors
 	if (nr < ZERO_APROX && nr > -ZERO_APROX) {
+		if (print) {
+			printf("Ohh no");
+		}
 		return -1;
 	}
 	if (skip_dist) {
+		if (print) {
+			printf("pdist: skip\n");
+		}
 		return 1;
 	}
 
@@ -75,6 +89,9 @@ COORD_T ray_intersect_plane(plane_t *p, ray_t *ray, bool skip_dist)
 	vector_sub(&tmp, &tmp, ray->start);
 
 	COORD_T t = vector_dot(&tmp, p->norm) / nr;
+	if (print) {
+		printf("pdist: %f\n", t);
+	}
 	return t;
 }
 
@@ -102,7 +119,10 @@ object_t *ray_cast(space_t *s, ray_t *r, COORD_T *dist_ret, bool chk, COORD_T ch
 	while (o) {
 		COORD_T d = ray_intersect(o, r, false);
 
-		if (d > 0) {
+		if (print)
+			printf("Distance: %f\n", d);
+
+		if (d > ZERO_APROX) {
 			if (chk && chk_dist > d) {
 				if (dist_ret) {
 					*dist_ret = d;
@@ -143,16 +163,23 @@ color_t *ray_trace(space_t *s, unsigned int x, unsigned int y)
 		return NULL;
 	}
 
-	// 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);
+	
+	// And vector towards viewer
+	//printf("point: "); vector_print(r.start);
+	vector_t V;
+	vector_sub(&V, &s->view.position, r.start);
+	// Normalice it
+	vector_scale_inv(&V, &V, vector_len(&V));
+	//printf("V: "); vector_print(&V);
 
 	// Hit color
-	color_t *c = color_set(NULL, 0, 0, 0);
+	color_t *c = color_set(NULL, s->ambient.r, s->ambient.g, s->ambient.b);
 
 	// Cast light rays
 	light_t *light = s->lights;
@@ -162,26 +189,49 @@ color_t *ray_trace(space_t *s, unsigned int x, unsigned int y)
 		vector_sub(&l, light->pos, r.start);
 		COORD_T d = vector_len(&l);
 
+		vector_scale_inv(&l, &l, vector_len(&l));
+
 		// Find obstacles
+		if (print) printf("Starting\n");
 		r.direction = &l;
 		object_t *obs = ray_cast(s, &r, NULL, true, d);
 		if (obs) {
+			if (print)
+				printf("Light ray hit\n");
+
 			light = light->next;
 			continue;
 		}
+			if (print)
+				printf("Light ray went through\n");
 		
-		// Calculate unit
-		vector_scale_inv(&l, &l, vector_len(&l));
+		// Calculate Deffuse part
 		color_t tmp;
-		color_scale(&tmp, light->defuse, vector_dot(&l, &n));
-		color_add(c, &tmp, c);
-			
+		COORD_T cl = vector_dot(&l, &n);
+		if (cl > 0) {
+			color_scale(&tmp, light->defuse, cl * o->m->defuse);
+			color_add(c, &tmp, c);
+		}
+
+		// 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);
+		//printf("R: ");vector_print(&R);
+		
+		// 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(c, &tmp, c);
+		}
+
 		light = light->next;
 	}
 
-	if (o->m) {
-		color_scale_vector(c, c, &o->m->color);
-	}
+	color_scale_vector(c, c, &o->m->color);
 
 	return c;
 }
diff --git a/scene.c b/scene.c
index 99ae0e8..5a41041 100644
--- a/scene.c
+++ b/scene.c
@@ -27,11 +27,13 @@ object_t *add_sphere(space_t *s, vector_t *c, COORD_T r, material_t *m)
 	return o;
 }
 
-object_t *add_plane(space_t *s, vector_t *start, vector_t *dir)
+object_t *add_plane(space_t *s, vector_t *start, vector_t *dir, material_t *m)
 {
 	object_t *o = (object_t *) malloc(sizeof(object_t));
 
 	o->type = TYPE_PLANE;
+	o->m = m;
+
 	o->pl.start = start;
 	o->pl.norm = dir;
 
@@ -40,12 +42,13 @@ 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 *defuse)
+light_t *add_light(space_t *s, vector_t *pos, color_t *defuse, color_t *specular)
 {
 	light_t *o = (light_t *) malloc(sizeof(light_t));
 
 	o->pos = pos;
 	o->defuse = defuse;
+	o->specular = specular;
 
 	if (s) {
 		o->next = s->lights;
diff --git a/scene.h b/scene.h
index 7efb5cd..489aece 100644
--- a/scene.h
+++ b/scene.h
@@ -24,12 +24,17 @@ typedef struct {
 typedef struct light_s{
 	vector_t *pos;
 	color_t *defuse;
+	color_t *specular;
 
 	struct light_s *next;
 } light_t;
 
 typedef struct {
 	vector_t color;
+
+	COORD_T defuse;
+	COORD_T specular;
+	unsigned int shine;
 } material_t;
 
 // General object structure
@@ -50,11 +55,13 @@ typedef struct {
 	viewpoint_t view;
 	object_t *objects;
 	light_t *lights;
+
+	color_t ambient;
 } space_t;
 
 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 *defuse);
+object_t *add_plane(space_t *s, vector_t *start, vector_t *dir, material_t *m);
+light_t *add_light(space_t *s, vector_t *pos, color_t *defuse, color_t *specular);
 
 void obj_norm_at(object_t *o, vector_t *dest, vector_t *point);
 
diff --git a/vector.h b/vector.h
index 2fcb648..e794f05 100644
--- a/vector.h
+++ b/vector.h
@@ -1,8 +1,8 @@
 #ifndef VECTOR_H
 #define VECTOR_H
 	
-#define COORD_T float
-#define ZERO_APROX 1e-5
+#define COORD_T double
+#define ZERO_APROX 1e-6
 
 typedef struct {
 	COORD_T x;