Added phong light model and fixed sphere intersect

1 files changed, 66 insertions, 16 deletions

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;
 }