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

examples/OpenGLWindow/Shaders/pointSpriteVS.glsl

@@ -0,0 +1,46 @@
+#version 330
+precision highp float;
+
+
+
+layout (location = 0) in vec4 position;
+layout (location = 1) in vec4 instance_position;
+layout (location = 3) in vec2 uvcoords;
+layout (location = 4) in vec3 vertexnormal;
+layout (location = 5) in vec4 instance_color;
+layout (location = 6) in vec3 instance_scale;
+
+
+uniform float screenWidth = 700.f;
+uniform mat4 ModelViewMatrix;
+uniform mat4 ProjectionMatrix;
+
+out Fragment
+{
+     vec4 color;
+} fragment;
+
+
+
+//
+// vector rotation via quaternion
+//
+
+out vec3 ambient;
+
+void main(void)
+{
+	ambient = vec3(0.3,.3,0.3);
+		
+		
+	vec4 axis = vec4(1,1,1,0);
+	vec4 vertexPos = ProjectionMatrix * ModelViewMatrix *(instance_position);
+	vec3 posEye = vec3(ModelViewMatrix * vec4(instance_position.xyz, 1.0));
+   float dist = length(posEye);
+	float pointRadius = 1.f;
+    gl_PointSize = instance_scale.x * pointRadius * (screenWidth / dist);
+
+	gl_Position = vertexPos;
+	
+	fragment.color = instance_color;
+}