float2   ViewportSize;		// Width and height of viewport window
float4x4 TransformMatrix;	// Used to transform vertices if necessary

// Applies a transformation matrix, converts from screen space to clip space
void LineVertexShader( inout float4 position: POSITION, inout float4 color : COLOR0 )
{       
    // Apply transformation matrix (translations, scaling, rotations)
    position = mul(position, TransformMatrix);

	// Viewport adjustment.
	position.xy /= ViewportSize;
	position.xy *= float2(2, -2);
	position.xy -= float2(1, -1);
}

// Simply returns the color of the pixel
float4 LinePixelShader(float4 color : COLOR0) : COLOR
{
	return color;
}

technique RenderLines
{
    pass P0
    {
        VertexShader = compile vs_1_1 LineVertexShader();
        PixelShader = compile ps_1_1 LinePixelShader();
    }
}