//----------------------------------------------------------------------------------------------------------
// X-PostProcessing Library
// https://github.com/QianMo/X-PostProcessing-Library
// Copyright (C) 2020 QianMo. All rights reserved.
// Licensed under the MIT License 
// You may not use this file except in compliance with the License.You may obtain a copy of the License at
// http://opensource.org/licenses/MIT
//----------------------------------------------------------------------------------------------------------

Shader "Hidden/X-PostProcessing/Glitch/RGBSplit"
{
	HLSLINCLUDE
	
	#include "../../../Shaders/StdLib.hlsl"
	#include "../../../Shaders/XPostProcessing.hlsl"
	
	
	uniform half4 _Params;
	uniform half3 _Params2;

	#define _Fading _Params.x
	#define _Amount _Params.y
	#define _Speed _Params.z
	#define _CenterFading _Params.w
	#define _TimeX _Params2.x
	#define _AmountR _Params2.y
	#define _AmountB _Params2.z

	half4 Frag_Horizontal(VaryingsDefault i): SV_Target
	{
		
		float2 uv = i.texcoord.xy;
		half time = _TimeX * 6 * _Speed;
		half splitAmount = (1.0 + sin(time)) * 0.5;
		splitAmount *= 1.0 + sin(time * 2) * 0.5;
		splitAmount = pow(splitAmount, 3.0);
		splitAmount *= 0.05;
		float distance = length(uv - float2(0.5, 0.5));
		splitAmount *=  _Fading * _Amount;
		splitAmount *= lerp(1, distance, _CenterFading);

		half3 colorR = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, float2(uv.x + splitAmount * _AmountR, uv.y)).rgb;
		half4 sceneColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, uv);
		half3 colorB = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, float2(uv.x - splitAmount * _AmountB, uv.y)).rgb;

		half3 splitColor = half3(colorR.r, sceneColor.g, colorB.b);
		half3 finalColor = lerp(sceneColor.rgb, splitColor, _Fading);

		return half4(finalColor, 1.0);

	}

	half4 Frag_Vertical(VaryingsDefault i) : SV_Target
	{

		float2 uv = i.texcoord.xy;
		half time = _TimeX * 6 * _Speed;
		half splitAmount = (1.0 + sin(time)) * 0.5;
		splitAmount *= 1.0 + sin(time * 2) * 0.5;
		splitAmount = pow(splitAmount, 3.0);
		splitAmount *= 0.05;
		float distance = length(uv - float2(0.5, 0.5));
		splitAmount *= _Fading * _Amount;
		splitAmount *= _Fading * _Amount;

		half3 colorR = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, float2(uv.x , uv.y + splitAmount * _AmountR)).rgb;
		half4 sceneColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, uv);
		half3 colorB = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, float2(uv.x, uv.y - splitAmount * _AmountB)).rgb;

		half3 splitColor = half3(colorR.r, sceneColor.g, colorB.b);
		half3 finalColor = lerp(sceneColor.rgb, splitColor, _Fading);

		return half4(finalColor, 1.0);

	}
	
	half4 Frag_Horizontal_Vertical(VaryingsDefault i) : SV_Target
	{

		float2 uv = i.texcoord.xy;
		half time = _TimeX * 6 * _Speed;
		half splitAmount = (1.0 + sin(time)) * 0.5;
		splitAmount *= 1.0 + sin(time * 2) * 0.5;
		splitAmount = pow(splitAmount, 3.0);
		splitAmount *= 0.05;
		float distance = length(uv - float2(0.5, 0.5));
		splitAmount *= _Fading * _Amount;
		splitAmount *= _Fading * _Amount;

		float splitAmountR = splitAmount * _AmountR;
		float splitAmountB = splitAmount * _AmountB;

		half3 colorR = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, float2(uv.x + splitAmountR, uv.y + splitAmountR)).rgb;
		half4 sceneColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, uv);
		half3 colorB = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, float2(uv.x - splitAmountB, uv.y - splitAmountB)).rgb;

		half3 splitColor = half3(colorR.r, sceneColor.g, colorB.b);
		half3 finalColor = lerp(sceneColor.rgb, splitColor, _Fading);

		return half4(finalColor, 1.0);

	}


	ENDHLSL
	

	SubShader
	{
		Cull Off ZWrite Off ZTest Always
		
		Pass
		{
			HLSLPROGRAM

			#pragma vertex VertDefault
			#pragma fragment Frag_Horizontal

			ENDHLSL

		}

		Pass
		{
			HLSLPROGRAM

			#pragma vertex VertDefault
			#pragma fragment Frag_Vertical

			ENDHLSL

		}

		Pass
		{
			HLSLPROGRAM

			#pragma vertex VertDefault
			#pragma fragment Frag_Horizontal_Vertical

			ENDHLSL

		}
	}
}