implement image atlasing and tiling

resources/shaders/tiling.fs

@@ -0,0 +1,16 @@
+#version 330 core
+
+uniform sampler2D diffuseMap;
+uniform vec2 textureTiling;
+
+in vec2 fragTexCoord;
+in vec2 fragTexCoord2;
+in vec4 fragColor;
+
+out vec4 outColor;
+
+void main()
+{
+    vec2 texCoord = (floor(fragTexCoord*textureTiling) + fract(fragTexCoord2)) / textureTiling;
+    outColor = texture(diffuseMap, texCoord);
+}