Add PhongMaterial struct

src/model/obj.h

@@ -25,6 +25,14 @@ struct triangle {
 
 MAKE_LIST_TYPE(Triangle);
 
+typedef struct phong_material PhongMaterial;
+struct phong_material {
+  f32 specular;
+  f32 diffuse;
+  f32 ambient;
+  f32 shininess;
+};
+
 typedef struct model Model;
 struct model {
   LIST_TYPE(V3f) * vertices;
@@ -33,6 +41,7 @@ struct model {
   LIST_TYPE(Triangle) * triangles;
   Image *texture;
   Image *normal;
+  PhongMaterial material;
 };
 
 Model load_obj_file(Arena *arena, const char *filename, const char *texture,