//**************************************************************************/
// Copyright (c) 2010 Autodesk, Inc.
// All rights reserved.
// 
// These coded instructions, statements, and computer programs contain
// unpublished proprietary information written by Autodesk, Inc., and are
// protected by Federal copyright law. They may not be disclosed to third
// parties or copied or duplicated in any form, in whole or in part, without
// the prior written consent of Autodesk, Inc.

#include "Common.cgh"

// The source texture
texture gSourceTex : SourceTexture
<
    string UIName = "Source Texture";
>;

// Sampler of source texture
sampler2D gSourceSamp = sampler_state
{
    Texture = <gSourceTex>;
};

// The 2nd source texture
texture gSourceTex2 : SourceTexture2
<
    string UIName = "Source Texture 2";
>;

// Sampler of 2nd source texture
sampler2D gSourceSamp2 = sampler_state
{
    Texture = <gSourceTex2>;
};

// Amount to blend source
float gBlendSrc = 0.3f;
float4 gUVTransform : RelativeViewportDimensions;

// Simple blending between 2 images
float4 PS_Blend(VS_TO_PS_ScreenQuad In) : COLOR0
{
    float4 source = tex2D(gSourceSamp, In.UV * gUVTransform.zw + gUVTransform.xy);
    float4 source2 = tex2D(gSourceSamp2, In.UV * gUVTransform.zw + gUVTransform.xy);
	float4 result = float4( lerp(source2, source, gBlendSrc).xyz, source.a);		
    return result;
}

float4 PS_AlphaBlend(VS_TO_PS_ScreenQuad In) : COLOR0
{
    float4 source = tex2D(gSourceSamp, In.UV * gUVTransform.zw + gUVTransform.xy);
    float4 source2 = tex2D(gSourceSamp2, In.UV * gUVTransform.zw + gUVTransform.xy);
	float4 result = lerp(source2, source, source.a);	
    return result;
}

float4 PS_Add(VS_TO_PS_ScreenQuad In) : COLOR0
{
    float4 source = tex2D(gSourceSamp, In.UV * gUVTransform.zw + gUVTransform.xy);
    float4 source2 = tex2D(gSourceSamp2, In.UV * gUVTransform.zw + gUVTransform.xy);
	return source2 + source;
}


// The main technique.
technique Main
{
    pass p0
    {
        VertexShader = compile glslv VS_ScreenQuad();
        PixelShader = compile glslf PS_AlphaBlend();
    }
}

technique AlphaBlend
{
    pass p0
    {
        VertexShader = compile glslv VS_ScreenQuad();
        PixelShader = compile glslf PS_Blend();
    }
}

technique Add
{
    pass p0
    {
        VertexShader = compile glslv VS_ScreenQuad();
        PixelShader = compile glslf PS_Add();
    }
}