move shaders to .glsl files and stringify to .h file.

add crude screenshot facility (using F1 key), it can also be used for debugging
start with shadows using shadowmap, not working yet
add experimental 'ignore' body index in raycast, using b3HitInfo.m_m_hitResult2

btgui/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;
+}