Introduce RgbaColorRenderer class.

glsl/color.vert

@@ -0,0 +1,8 @@
+uniform vec2 Scroll;
+uniform vec2 r1, r2;		// matrix elements
+void main()
+{
+	vec2 p = (gl_Vertex.xy - Scroll.xy)*r1 + r2;
+	gl_Position = vec4(p.x,p.y,0,1);
+	gl_FrontColor = gl_MultiTexCoord0;
+}