Diamond Fractal Image Effect Shader

Shader "Hidden/DiamondFractalImageEffect"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _FractalFactor ("Fractal Factor", float) = 10.0
        _FractalDistance ("Fractal Distance", float) = 0.0
        _SampleDistance ("Sample Distance", float) = 0.0
        _WarpStart ("Warp Start Distance", Range(0.0, 1.0)) = 0.5
        _UvZoom ("UV Zoom", float) = 1.0
    }
    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;
            float _FractalFactor;
            float _FractalDistance;
            float _SampleDistance;
            float _WarpStart;
            float _UvZoom;

            fixed4 frag (v2f i) : SV_Target
            {
                float2 center = float2(0.5, 0.5);
                float2 zuv = (i.uv - center) * _UvZoom + center;
                float2 st = zuv;
                st = st * 2.0 - 1.0;

                float t = length(abs(st) - _FractalDistance);
                float t2 = frac(t * _FractalFactor);
                float t3 = smoothstep(_WarpStart, 1.0, t2);

                float2 away = normalize(st - center) * (_SampleDistance * t3);

                fixed4 col = tex2D(_MainTex, zuv + away);

                return col;
            }
            ENDCG
        }
    }
}