134 lines
4.4 KiB
Plaintext
134 lines
4.4 KiB
Plaintext
Shader "Kaiju/Julia"
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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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_MaxIterations("Max Iterations", range(0, 555)) = 255
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_Pan("Pan", vector) = (0.5, 0.0, 0.0, 0.0)
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_Zoom("Zoom", range(0, 4)) = 3
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_Aspect("Aspect", range(0, 4)) = 1
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_JuliaSeed("JuliaSeed", vector) = (0.39, -0.2, 0.0, 0.0)
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_Colors("Colors", vector) = (3.0, 3.0, 3.0, 0.0)
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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 enable_d3d11_debug_symbols
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#pragma target 3.0
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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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float _MaxIterations;
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float2 _Pan;
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float _Zoom;
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float _Aspect;
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float2 _JuliaSeed;
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float3 _Colors;
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float ComputeValue(float2 v, float2 offset) {
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float vxsquare = 0;
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float vysquare = 0;
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float iteration;
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for (iteration = 0; iteration < _MaxIterations; iter++) {
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}
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// do {
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// vxsquare = v.x * v.x;
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// vysquare = v.y * v.y;
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// v = float2(vxsquare - vysquare, v.x * v.y * 2) + offset;
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// iteration++;
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// if ((lastIteration == _MaxIterations) && (vxsquare + vysquare) > 4.0) {
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// lastIteration = iteration + 1;
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// }
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// } while (iteration < lastIteration);
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// return (float(iteration) - (log(log(sqrt(vxsquare + vysquare))) / log(2.0))) / float(_MaxIterations);
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}
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// for each pixel (Px, Py) on the screen do
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// x0 := scaled x coordinate of pixel (scaled to lie in the Mandelbrot X scale (-2.5, 1))
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// y0 := scaled y coordinate of pixel (scaled to lie in the Mandelbrot Y scale (-1, 1))
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// x := 0.0
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// y := 0.0
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// iteration := 0
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// max_iteration := 1000
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// // Here N = 2^8 is chosen as a reasonable bailout radius.
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// while x*x + y*y ≤ (1 << 16) and iteration < max_iteration do
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// xtemp := x*x - y*y + x0
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// y := 2*x*y + y0
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// x := xtemp
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// iteration := iteration + 1
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// // Used to avoid floating point issues with points inside the set.
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// if iteration < max_iteration then
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// // sqrt of inner term removed using log simplification rules.
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// log_zn := log(x*x + y*y) / 2
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// nu := log(log_zn / log(2)) / log(2)
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// // Rearranging the potential function.
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// // Dividing log_zn by log(2) instead of log(N = 1<<8)
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// // because we want the entire palette to range from the
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// // center to radius 2, NOT our bailout radius.
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// iteration := iteration + 1 - nu
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// color1 := palette[floor(iteration)]
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// color2 := palette[floor(iteration) + 1]
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// // iteration % 1 = fractional part of iteration.
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// color := linear_interpolate(color1, color2, iteration % 1)
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// plot(Px, Py, color)
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float4 Mandelbrot_PixelShader(float2 texCoord : TEXCOORD0) : COLOR0 {
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float2 v = (texCoord - 0.5) * _Zoom * float2(1, _Aspect) - _Pan;
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float val = ComputeValue(v, v);
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return float4(sin(val * _Colors.x), sin(val * _Colors.y), sin(val * _Colors.z), 1);
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}
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float4 Julia_PixelShader(float2 texCoord : TEXCOORD0) : COLOR0 {
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_JuliaSeed = float2(sin(_Time.y), cos(_Time.y));
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float2 v = (texCoord - 0.5) * _Zoom * float2(1, _Aspect) - _Pan;
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float val = ComputeValue(v, _JuliaSeed);
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return float4(sin(val * _Colors.x), sin(val * _Colors.y), sin(val * _Colors.z), 1);
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}
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float4 frag (v2f i) : SV_Target {
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// return Julia_PixelShader(i.uv);
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return Mandelbrot_PixelShader(i.uv);
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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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