VHS Noise

VHS Noise

//https://www.shadertoy.com/view/XtBXDt
Shader "Hidden/Shader"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
	}
	SubShader
	{
		// No culling or depth
		Cull Off ZWrite Off ZTest Always

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			
			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = v.uv;
				return o;
			}
			
			sampler2D _MainTex;

      #define PI 3.14159265

float3 tex2DSample( sampler2D _tex, float2 _p ){
  float3 col = tex2D( _tex, _p ).xyz;
  if ( 0.5 < abs( _p.x - 0.5 ) ) {
    col = float3( 0.1,0.1,0.1);
  }
  return col;
}

float hash( float2 _v ){
  return frac( sin( dot( _v, float2( 89.44, 19.36 ) ) ) * 22189.22 );
}

float iHash( float2 _v, float2 _r ){
  float h00 = hash( float2( floor( _v * _r + float2( 0.0, 0.0 ) ) / _r ) );
  float h10 = hash( float2( floor( _v * _r + float2( 1.0, 0.0 ) ) / _r ) );
  float h01 = hash( float2( floor( _v * _r + float2( 0.0, 1.0 ) ) / _r ) );
  float h11 = hash( float2( floor( _v * _r + float2( 1.0, 1.0 ) ) / _r ) );
  float2 ip = float2( smoothstep( float2( 0.0, 0.0 ), float2( 1.0, 1.0 ), fmod( _v*_r, 1. ) ) );
  return ( h00 * ( 1. - ip.x ) + h10 * ip.x ) * ( 1. - ip.y ) + ( h01 * ( 1. - ip.x ) + h11 * ip.x ) * ip.y;
}

float noise( float2 _v ){
  float sum = 0.;
  for( int i=1; i<9; i++ )
  {
    float pp = 2. * pow( 2., float( i )  );
    sum += iHash( _v + float2( i ,i), float2(pp,pp) / pow( 2., float( i ) ));
  }
  return sum;
}

			fixed4 frag (v2f i) : SV_Target
			{



  float2 uv = i.uv;
  float2 uvn = uv;
  float3 col = float3(0,0,0);

  // tape wave
  uvn.x += ( noise( float2( uvn.y, _Time.y ) ) - 0.5 )* 0.005;
  uvn.x += ( noise( float2( uvn.y * 100.0, _Time.y * 10.0 ) ) - 0.5 ) * 0.01;

  // tape crease
  float tcPhase = clamp( ( sin( uvn.y * 8.0 - _Time.y * PI * 1.2 ) - 0.92 ) * noise( float2( _Time.y,_Time.y ) ), 0.0, 0.01 ) * 10.0;
  float tcNoise = max( noise( float2( uvn.y * 100.0, _Time.y * 10.0 ) ) - 0.5, 0.0 );
  uvn.x = uvn.x - tcNoise * tcPhase;

  // switching noise
  float snPhase = smoothstep( 0.03, 0.0, uvn.y );
  uvn.y += snPhase * 0.3;
  uvn.x += snPhase * ( ( noise( float2( uv.y * 100.0, _Time.y * 10.0 ) ) - 0.5 ) * 0.2 );
    
  col = tex2D( _MainTex, uvn );
  col *= 1.0 - tcPhase;
  col = lerp(
    col,
    col.yzx,
    snPhase
  );

  // bloom
  for( float x = -4.0; x < 2.5; x += 1.0 ){
    col.xyz += float3(
      tex2DSample( _MainTex, uvn + float2( x - 0.0, 0.0 ) * 7E-3 ).x,
      tex2DSample( _MainTex, uvn + float2( x - 2.0, 0.0 ) * 7E-3 ).y,
      tex2DSample( _MainTex, uvn + float2( x - 4.0, 0.0 ) * 7E-3 ).z
    ) * 0.1;
  }
  col *= 0.6;

  // ac beat
  col *= 1.0 + clamp( noise( float2( 0.0, uv.y + _Time.y * 0.2 ) ) * 0.6 - 0.25, 0.0, 0.1 );

return float4( col, 1.0 );
}
ENDCG
}
}
}