only use xyzw coordinates in glm structures

src/game.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#define GLM_FORCE_XYZW_ONLY
 #include <glm/glm.hpp>
 using glm::vec3;
 using glm::dvec3;

src/main.cpp

@@ -24,6 +24,7 @@
 #include <cmath>
 
 #include <SDL2/SDL.h>
+#define GLM_FORCE_XYZW_ONLY
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>