Fix barycentric coordinates calculation (#2)

Reviewed-on: #2

	* Set up for debugging
	* Replace get_barycentric_coords with different calculation
	* Update commented lines
	* Add V3_ELEM_COUNT macro
	* Change loop in barycentric coordinates calculation function
	* Update debug values
	* Simplify barycentric coordinates function
	* Remove debug lines
Co-authored-by: Abdelrahman <said.abdelrahman89@gmail.com>
Co-committed-by: Abdelrahman <said.abdelrahman89@gmail.com>

src/main.c

@@ -41,8 +41,8 @@ int main(void) {
   PhongMaterial material = {
       .ambient = 0.3f,
       .diffuse = 1.5f,
-      .specular = 0.5f,
-      .shininess = 0.1f,
+      .specular = 2.0f,
+      .shininess = 1.5f,
   };
   obj.material = material;