Pass depth scale factors to vertex shaders.

glsl/rgba.vert

@@ -1,5 +1,5 @@
-uniform vec2 Scroll;
-uniform vec2 r1, r2;
+uniform vec3 Scroll;
+uniform vec3 r1, r2;
 
 attribute vec4 aVertexPosition;
 attribute vec4 aVertexTexCoord;
@@ -7,7 +7,6 @@ varying vec4 vTexCoord;
 
 void main()
 {
-	vec2 p = (aVertexPosition.xy - Scroll.xy)*r1 + r2;
-	gl_Position = vec4(p.x,p.y,0,1);
+	gl_Position = vec4((aVertexPosition.xyz - Scroll.xyz) * r1 + r2, 1);
 	vTexCoord = aVertexTexCoord;
 }