Create material abstraction

include/obj.h

@@ -1,22 +1,18 @@
 #ifndef OBJ_H
 #define OBJ_H
 
+#include "material.h"
 #include "ray.h"
 
-#define SPHERE(x, y, z, r) \
+#define SPHERE(x, y, z, r, m) \
 	{ \
 		.intersect = intersect_sphere, \
+		.material = m, \
 		.params = { \
 			.sphere = { .centre = { x, y, z }, .radius = r }, \
 		}, \
 	}
 
-typedef struct {
-	vec3_t point, normal;
-	double t;
-	bool front;
-} hit_t;
-
 typedef struct {
 	vec3_t centre;
 	double radius;
@@ -32,6 +28,7 @@ typedef bool intersect_fn_t(
 
 typedef struct {
 	intersect_fn_t *intersect;
+	material_t material;
 	obj_params_t params;
 } obj_t;