Added cubemap stars

core/assets/shaders/cubemap.frag

@@ -0,0 +1,7 @@
+varying vec3 v_texCoords;
+
+uniform samplerCube u_cubemap;
+
+void main(){
+    gl_FragColor = textureCube(u_cubemap, v_texCoords);
+}

core/assets/shaders/cubemap.vert

@@ -0,0 +1,12 @@
+attribute vec3 a_position;
+
+varying vec3 v_texCoords;
+
+uniform mat4 u_proj;
+
+const float SCALE = 50.0;
+
+void main(){
+    v_texCoords = a_position;
+    gl_Position = u_proj * vec4(a_position * SCALE, 1.0);
+}