RapidOldTVVignette.shader

Shader "Hidden/X-PostProcessing/RapidOldTVVignette"
{
	
	HLSLINCLUDE
	
	#include "../../../Shaders/StdLib.hlsl"
	#include "../../../Shaders/XPostProcessing.hlsl"
	
	struct VertexOutput
	{
		float4 vertex: SV_POSITION;
		float4 texcoord: TEXCOORD0;
	};
	
	half _VignetteIndensity;
	half2 _VignetteCenter;
	half4 _VignetteColor;
	
	
	VertexOutput Vert(AttributesDefault v)
	{
		VertexOutput o;
		o.vertex = float4(v.vertex.xy, 0.0, 1.0);
		o.texcoord.xy = TransformTriangleVertexToUV(v.vertex.xy);
		
		#if UNITY_UV_STARTS_AT_TOP
			o.texcoord.xy = o.texcoord.xy * float2(1.0, -1.0) + float2(0.0, 1.0);
		#endif
		
		// uv [0, 1] ->[-0.5, 0.5]
		o.texcoord.zw = o.texcoord.xy - _VignetteCenter;
		
		return o;
	}
	
	float4 Frag(VertexOutput i): SV_Target
	{
		float4 finalColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.texcoord.xy);
		
		//普通vignette曲线 -> Old TV曲线
		i.texcoord.zw *= i.texcoord.zw;
		
		//求解vignette强度
		float vignetteIndensity = saturate(1.0 - dot(i.texcoord.zw, i.texcoord.zw) * _VignetteIndensity * 20);
		
		return vignetteIndensity * finalColor;
	}
	
	
	float4 Frag_ColorAdjust(VertexOutput i): SV_Target
	{
		float4 finalColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.texcoord.xy);
		
		//普通vignette曲线 -> Old TV曲线
		i.texcoord.zw *= i.texcoord.zw;
		
		//求解vignette强度
		float vignetteIndensity = saturate(1.0 - dot(i.texcoord.zw, i.texcoord.zw) * _VignetteIndensity * 20);
		
		//基于vignette强度，插值VignetteColor颜色和场景颜色
		finalColor.rgb = lerp(_VignetteColor.rgb, finalColor.rgb, vignetteIndensity);
		
		return half4(finalColor.rgb, _VignetteColor.a);
	}
	
	
	ENDHLSL
	
	SubShader
	{
		Cull Off ZWrite Off ZTest Always
		
		Pass
		{
			HLSLPROGRAM
			
			#pragma vertex Vert
			#pragma fragment Frag
			
			ENDHLSL
			
		}
		
		Pass
		{
			HLSLPROGRAM
			
			#pragma vertex Vert
			#pragma fragment Frag_ColorAdjust
			
			ENDHLSL
			
		}
	}
}