132 lines
4.1 KiB
Plaintext
132 lines
4.1 KiB
Plaintext
Shader "Explorer/Mandelbrot"
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{
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Properties
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{
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_MainTex ("Texture", 2D) = "white" {}
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// first two numbers are center of area, second two - size of area
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_Area("Area", vector) = (0, 0, 4 ,4)
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_Angle("Angle", range(-3.1415, 3.1415)) = 0
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_MaxIter("Max Iterations", range(0, 555)) = 255
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_Speed("Speed", range(0, 1)) = 0.1
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_EscapeRadius("EscapeRadius", range(2, 2000)) = 255
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_SpectrumTexture("SpectrumTexture", 2D) = "white" {}
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_SpectrumSize("SpectrumSize", float) = 16
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_ThemeTexture("ThemeTexture", 2D) = "white" {}
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_ThemeSize("ThemeSize", float) = 16
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}
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SubShader
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{
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// No culling or depth
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Cull Off ZWrite Off ZTest Always
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Pass
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{
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CGPROGRAM
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#pragma vertex vert
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#pragma fragment frag
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#include "UnityCG.cginc"
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struct appdata
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{
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float4 vertex : POSITION;
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float2 uv : TEXCOORD0;
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};
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struct v2f
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{
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float2 uv : TEXCOORD0;
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float4 vertex : SV_POSITION;
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};
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v2f vert (appdata v)
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{
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v2f o;
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o.vertex = UnityObjectToClipPos(v.vertex);
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o.uv = v.uv;
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return o;
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}
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float4 _Area;
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int _MaxIter;
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float _EscapeRadius;
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float _Speed;
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sampler2D _SpectrumTexture;
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int _SpectrumSize;
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sampler2D _ThemeTexture;
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int _ThemeSize;
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sampler2D _MainTex;
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fixed4 frag (v2f i) : SV_Target {
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// drawing stuff
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float2 uv = i.uv - 0.5;
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float2 offset = _Area.xy + uv * _Area.zw;
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// cool modulation
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float sub = tex2D(_SpectrumTexture, 0.0);
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float bass = tex2D(_SpectrumTexture, 0.25);
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float mids = tex2D(_SpectrumTexture, 0.50);
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float highs = tex2D(_SpectrumTexture, 0.75);
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float r = lerp(2.0, 200, bass);
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float maxIterations = lerp(2.0, 500, sub);
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// fractal bits
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float r2 = r*r;
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float2 c = _Area.xy + uv * _Area.zw;
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float2 z = 0;
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float2 zNext;
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int iter;
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for (iter = 0; iter < maxIterations; iter ++)
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{
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// f(z) = z^2 + c
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zNext.x = z.x * z.x - z.y * z.y + c.x;
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zNext.y = 2 * z.x * z.y + c.y;
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z = zNext;
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// unbounded
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if (length(zNext) > r)
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break;
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}
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// in the set
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// make it white
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if (iter >= maxIterations) {
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return 0;
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return 1;
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}
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float val = iter / float(maxIterations);
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float4 col = tex2D(_ThemeTexture, float2(sub, 1.0));
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return col * val;
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// return float4(val, val, val, 1.0);
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// return tex2D(_ThemeTexture, highs);
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// float col = tex2D(_ThemeTexture, float2(highs * val, 1.0));
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// return col;
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// from spinny curvy brot
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// float dist = length(z); // distance from origin
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// float fracIter = (dist - r) / (r2 - r); // linear interpolation
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// fracIter = log2(log(dist) / log(r) ); // double exponential interpolation
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// iter -= fracIter;
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// float m = sqrt(iter / _MaxIter);
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// float4 col = sin(float4(.3, .45, .65, 1) * m * 20)*.5 + .5; // procedural colors
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// col = tex2D(_MainTex, float2(m * _Repeat + _Time.y*_Speed, _Color));
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// col *= smoothstep(3, 0, fracIter);
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// float angle = atan2(z.x, z.y);
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// col *= 1 + sin(angle*2 + _Time.y*4)*.2;
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// return col;
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}
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ENDCG
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}
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}
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}
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