// license:BSD-3-Clause
// copyright-holders:Ryan Holtz
//-----------------------------------------------------------------------------
// Passthrough Effect
//-----------------------------------------------------------------------------

texture Diffuse;

sampler DiffuseSampler = sampler_state
{
	Texture   = <Diffuse>;
	MipFilter = NONE;
	MinFilter = NONE;
	MagFilter = NONE;
	AddressU = CLAMP;
	AddressV = CLAMP;
	AddressW = CLAMP;
};

//-----------------------------------------------------------------------------
// Vertex Definitions
//-----------------------------------------------------------------------------

struct VS_OUTPUT
{
	float4 Position : POSITION;
	float2 TexCoord : TEXCOORD0;
};

struct VS_INPUT
{
	float4 Position : POSITION;
	float4 Color : COLOR0;
	float2 TexCoord : TEXCOORD0;
	float2 Unused : TEXCOORD1;
};

struct PS_INPUT
{
	float2 TexCoord : TEXCOORD0;
};

//-----------------------------------------------------------------------------
// Passthrough Vertex Shader
//-----------------------------------------------------------------------------

uniform float2 ScreenDims;

VS_OUTPUT vs_main(VS_INPUT Input)
{
	VS_OUTPUT Output = (VS_OUTPUT)0;
	
	Output.Position = float4(Input.Position.xyz, 1.0f);
	Output.Position.xy /= ScreenDims;
	Output.Position.y = 1.0f - Output.Position.y;
	Output.Position.xy -= 0.5f;
	Output.Position *= float4(2.0f, 2.0f, 1.0f, 1.0f);
	
	Output.TexCoord = Input.TexCoord + 0.5f / ScreenDims;

	return Output;
}

//-----------------------------------------------------------------------------
// Passthrough Pixel Shader
//-----------------------------------------------------------------------------

float4 ps_main(PS_INPUT Input) : COLOR
{
	return tex2D(DiffuseSampler, Input.TexCoord);
}

//-----------------------------------------------------------------------------
// Passthrough Effect
//-----------------------------------------------------------------------------

technique DeconvergeTechnique
{
	pass Pass0
	{
		Lighting = FALSE;

		VertexShader = compile vs_3_0 vs_main();
		PixelShader  = compile ps_3_0 ps_main();
	}
}