CellularNoise.shader

Shader "Monica/CellularNoise"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			// make fog work
			#pragma multi_compile_fog
			
			#include "UnityCG.cginc"

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}

			float2 random2(float2 st)
			{
				st = float2(dot(st, float2(127.1, 311.7)),
					dot(st, float2(269.5, 183.3)));
				return -1.0 + 2.0 * frac(sin(st) * 43758.5453123);
			}

			float cellularnoise(float2 st, float n) {
				st *= n;

				float2 ist = floor(st);
				float2 fst = frac(st);

				float distance = 5;

				for (int y = -1; y <= 1; y++)
					for (int x = -1; x <= 1; x++)
					{
						float2 neighbor = float2(x, y);
						float2 p = 0.5 + 0.5 * sin(_Time.y + 6.2831 * random2(ist + neighbor));

						float2 diff = neighbor + p - fst;
						distance = min(distance, length(diff));
					}

				float color = distance * 0.5;

				return color;
			}

			fixed4 frag(v2f i) : SV_Target
			{

				return cellularnoise(i.uv, 4)*0.8*float4(2.05, 1.70, -2, 1) + float4(0.1,0.1,1.5,1);
			}
			ENDCG
		}
	}
}