//**************************************************************************/
// Copyright 2010 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.
float4x4 gWVPXf : WorldViewProjection < string UIWidget = "None"; >;

// The single filter input, i.e. the image to be filtered.
texture gInputTex : InputTexture
<
    string UIName = "Input Texture";
>;

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

// Gamma value.
float gGamma = 2.2f;

// Vertex shader input structure.
struct VS_INPUT
{
    float4 Pos : POSITION;
    float3 UV : TEXCOORD0;
};

// Vertex shader output structure.
struct VS_TO_PS
{
    float4 HPos : POSITION;
    float3 UV : TEXCOORD0;
};

// Vertex shader.
VS_TO_PS VS_Copy(VS_INPUT In)
{
    VS_TO_PS Out;
    
    // Transform the position from object space to clip space for output.
    Out.HPos = mul(gWVPXf, In.Pos);
    
    // Pass the texture coordinates unchanged.
    Out.UV = In.UV;
    
    return Out;
}

// Pixel shader.
float4 PS_Copy(VS_TO_PS In) : COLOR0
{
	float4 output = tex2D(gInputSampler, In.UV.xy);
	
    return float4( pow( output.xyz, 1.0 / gGamma ), output.w );
}

// The main technique.
technique Main
{
    pass p0
    {
        VertexProgram = compile glslv VS_Copy();
        FragmentProgram  = compile glslf PS_Copy();
    }
}