//**************************************************************************/
// Copyright 2014 Autodesk, Inc.
// All rights reserved.
// Use of this software is subject to the terms of the Autodesk license
// agreement provided at the time of installation or download, or which
// otherwise accompanies this software in either electronic or hard copy form.
//**************************************************************************/

// World-view-projection transformation.
uniform mat4 gWVPXf : WorldViewProjection;

// The single filter input, i.e. the image to be filtered.
uniform texture2D gInputTex : InputTexture;

// Filter input sampler.
uniform sampler2D gInputSamp = sampler_state
{
    Texture = <gInputTex>;
    //MinFilter = Point;
    //MagFilter = Point;
    //MipFilter = Point;
};

// Vertex shader input structure.
attribute VS_INPUT
{
    vec4 Pos : POSITION;
    vec2 UV : TEXCOORD0;
};

// Vertex shader output structure.
attribute VS_TO_PS
{
    vec2 VSUV : TEXCOORD0;
};

// Vertex shader.
GLSLShader VS_FilterMonochrome
{
	void main()
	{
        gl_Position = gWVPXf*Pos;
		
		// Pass the texture coordinates unchanged.
		VSUV = UV;
	}
}

// Pixel shader output structure.
attribute pixelOut
{
    vec4 colorOut: COLOR0;
}

// Pixel shader.
GLSLShader PS_FilterMonochrome
{
	void main()
	{
		// The luminance conversion factors for RGB.
		vec3 luminanceConv = vec3(0.2125f, 0.7154f, 0.0721f);

		// The color of the output pixel is the dot product of the input texture sample and the
		// luminance conversion factors, applied to all components.
		float result = dot(texture2D(gInputSamp, VSUV).xyz, luminanceConv);
		colorOut = vec4(result, result, result, 1.0f);
	}
}

// The main technique.
technique Main
{
    pass p0
    {
        VertexShader (in VS_INPUT, out VS_TO_PS) = VS_FilterMonochrome;
        PixelShader (in VS_TO_PS, out pixelOut) = PS_FilterMonochrome;
    }
}