// Made by Marot Satil for GShade, a fork of ReShade.
// You can follow me via @MarotSatil on Twitter, but I don't use it all that much and if you message me directly it's very likely to get flagged as spam.
// If you have questions about this shader or need to contact me for any other reason, reaching out to me via the username Marot on Discord is likely a better bet.
//
// This shader does exactly what it says it does.
//
// Copyright © 2023 Marot Satil
// This work is free. You can redistribute it and/or modify it under the
// terms of the Do What The Fuck You Want To Public License, Version 2,
// as published by Sam Hocevar.
//
//            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
//                    Version 2, December 2004
//
// Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
//
// Everyone is permitted to copy and distribute verbatim or modified
// copies of this license document, and changing it is allowed as long
// as the name is changed.
//
//            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
//   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
//
//  0. You just DO WHAT THE FUCK YOU WANT TO.

#include "ReShade.fxh"

uniform float3 fColor <
	ui_label = "Color To Replace";
	ui_type = "color";
> = float3(1.0, 1.0, 1.0);

uniform float fBlending <
	ui_label = "Opacity";
	ui_tooltip = "If this setting is above 0.0 (fully transparent), you will only be able to see its impact in screenshots.\n\nA value of 0.5 is 50\% transparent.";
	ui_type = "slider";
> = 0.0;

float4 ColorToAlphaPS(float4 pos : SV_Position, float2 texcoord : TEXCOORD) : SV_Target
{
	const float4 back = tex2D(ReShade::BackBuffer, texcoord);
	
	if (back.r == fColor.r && back.g == fColor.g && back.b == fColor.b)
	{
		if (fBlending == 0.0)
		{
			return float4(0.0, 0.0, 0.0, 0.0);
		}

		return float4(back.rgb, fBlending);
	}
	else
		return back;
}

technique ColorToAlpha
{
	pass
	{
		VertexShader = PostProcessVS;
		PixelShader = ColorToAlphaPS;
	}
}