Simplex Noise Shader Unity

SimplexNoise2D.Shader

Shader "Custom/SimplexNoise2D" {
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_Color2 ("Color2", Color) = (1,1,1,1)
		_Color3 ("Color3", Color) = (1,1,1,1)
		_Color4 ("Color4", Color) = (1,1,1,1)
	}
	SubShader {
		Pass {
			CGPROGRAM
				#pragma vertex vert
        #pragma fragment frag
        #include "UnityCG.cginc"
        // Sourced from: https://github.com/keijiro/NoiseShader/blob/master/Assets/HLSL/NoiseTest.shader
				#include "SimplexNoise2D.cginc"

        // vertex input: position, second UV
        struct appdata {
            float4 vertex : POSITION;
            float4 texcoord1 : TEXCOORD1;
        };

        struct v2f {
            float4 pos : SV_POSITION;
            float4 uv : TEXCOORD0;
        };
        
        v2f vert (appdata v) {
            v2f o;
            o.pos = UnityObjectToClipPos(v.vertex );
            o.uv = float4( v.texcoord1.xy, 0, 0 );
            return o;
        }
        
				float4 _Color;
				float4 _Color2;
				float4 _Color3;
				float4 _Color4;

        half4 frag( v2f i ) : SV_Target {
            float2 pos = snoise(i.uv + _Time[0])*((2.0+_SinTime[3])*0.5);
						float l = length(pos);
						if(l > 0.75) return _Color;
						else if(l > 0.5) return _Color2;
						else if(l > 0.25) return _Color3;
            return _Color4;
        }
			ENDCG
		}
	}
	FallBack "Diffuse"
}