add initial examples, replacing the 'Demos/Demos3'. Will make it work cross-platform, OpenGL3/OpenGL2 and add more examples to it.

examples/OpenGLWindow/Shaders/useShadowMapInstancingPS.glsl

@@ -0,0 +1,56 @@
+#version 330 core
+//precision highp float;
+
+in Fragment
+{
+     vec4 color;
+} fragment;
+
+in Vert
+{
+	vec2 texcoord;
+} vert;
+
+uniform sampler2D Diffuse;
+uniform sampler2DShadow shadowMap;
+
+in vec3 lightDir,normal,ambient;
+in vec4 ShadowCoord;
+
+out vec4 color;
+
+
+
+void main(void)
+{
+    vec4 texel = fragment.color*texture(Diffuse,vert.texcoord);//fragment.color;
+	vec3 ct,cf;
+	float intensity,at,af;
+	
+	intensity = clamp( dot( normalize(normal),lightDir ), 0,1 );
+	
+	cf = ambient;
+	af = 1.0;
+		
+	ct = texel.rgb;
+	at = texel.a;
+		
+	//float bias = 0.005f;
+	
+	float bias = 0.0001*tan(acos(intensity));
+	bias = clamp(bias, 0,0.01);
+
+
+	float visibility = texture(shadowMap, vec3(ShadowCoord.xy,(ShadowCoord.z-bias)/ShadowCoord.w));
+	
+	intensity*=2;
+	if (intensity>1)
+		intensity=1.f;
+	
+	visibility *= intensity;
+	
+	if (visibility<0.6)
+		visibility=0.6f;
+		
+	color  = vec4(ct * visibility, fragment.color.w);
+}