//----------------------------------------------------------------------------------------------------------
// 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
//----------------------------------------------------------------------------------------------------------

//reference : https://github.com/keijiro/KinoGlitch

Shader "Hidden/X-PostProcessing/Glitch/DigitalStripe"
{
	HLSLINCLUDE
	
	#include "../../../Shaders/XPostProcessing.hlsl"
	
	#pragma shader_feature NEED_TRASH_FRAME

	TEXTURE2D_SAMPLER2D(_NoiseTex, sampler_NoiseTex);

	uniform half _Indensity;
	uniform half4 _StripColorAdjustColor;
	uniform half _StripColorAdjustIndensity;

	
	half4 Frag(VaryingsDefault i): SV_Target
	{
		// 基础数据准备
		 half4 stripNoise = SAMPLE_TEXTURE2D(_NoiseTex, sampler_NoiseTex, i.texcoord);
		 half threshold = 1.001 - _Indensity * 1.001;

		// uv偏移
		half uvShift = step(threshold, pow(abs(stripNoise.x), 3));
		float2 uv = frac(i.texcoord + stripNoise.yz * uvShift);
		half4 source = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, uv);

#ifndef NEED_TRASH_FRAME
		return source;
#endif 	

		// 基于废弃帧插值
		half stripIndensity = step(threshold, pow(abs(stripNoise.w), 3)) * _StripColorAdjustIndensity;
		half3 color = lerp(source, _StripColorAdjustColor, stripIndensity).rgb;
		return float4(color, source.a);
	}
	
	ENDHLSL
	

	SubShader
	{
		Cull Off ZWrite Off ZTest Always
		
		Pass
		{
			HLSLPROGRAM
			
			#pragma vertex VertDefault
			#pragma fragment Frag
			
			ENDHLSL
			
		}
	}
}