Added frame buffer support.

assets/shaders/textured.frag

@@ -8,5 +8,6 @@ out vec4 FragColor;
 
 void main() {
   vec4 color = texture(u_Text, TexCoord);
-  FragColor = color;
+  FragColor = color + vec4(0.25, 0.25, 0.25, 1);
+  // FragColor = vec4(1, 0, 0, 1);
 }