Lightmap example. (#3043)

examples/shaders/resources/shaders/glsl330/lightmap.fs

@@ -0,0 +1,20 @@
+#version 330
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+in vec2 fragTexCoord2;
+in vec3 fragPosition;
+in vec4 fragColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform sampler2D texture1;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main() {
+	// Texel color fetching from texture sampler
+    vec4 texelColor = texture( texture0, fragTexCoord );
+    vec4 texelColor2 = texture( texture1, fragTexCoord2 );
+	finalColor = texelColor * texelColor2;
+}