156 lines
3.9 KiB
GLSL
156 lines
3.9 KiB
GLSL
Shader "CrispyPin/Lenia"
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{
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Properties
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{
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_LastFrame ("Texture", 2D) = "white" {}
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_GrowtCenter ("Growth fn center (mu)", Range(0, 1)) = 0.2
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_GrowthWidth ("Growth fn width (sigma / std deviation)", Range(0, 1)) = 0.07
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_Speed ("Speed factor", Range(0.001, 0.5)) = 0.1
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}
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SubShader
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{
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Tags { "RenderType"="Opaque" }
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LOD 100
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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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sampler2D _LastFrame;
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float _GrowtCenter;
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float _GrowthWidth;
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float _Speed;
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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 kernel(float p) {
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float r = p / 8.0;
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float k_sharpness = 28;
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float k_offset = 0.435;
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return exp(-((r - k_offset) * (r - k_offset)) * k_sharpness);
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// float r = p / _Radius;
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// // -- normal
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// return exp(-((r - _KOffset)*(r - _KOffset)) * _KSharpness);
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// -- example from the lenia paper
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// if (r >= 1) return 0;
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// const float alpha = 4;
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// return exp(alpha - alpha/(4.0 * r * (1.0 - r)));
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}
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inline float activation(float neighbors) {
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// return old_state * (neighbors > 2 && neighbors < 5) +
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// ((1 - old_state) * neighbors == 3);
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// const float sharpness = 1000.0;
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// float x = neighbors - _GrowtCenter;
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// return exp(-(x*x) * _GrowthWidth) * 2.0 - 1.0;
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const float mu = _GrowtCenter;
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const float sigma = _GrowthWidth;
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const float u = neighbors;
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return exp(-((u-mu) * (u-mu)) / (2 * sigma * sigma)) * 2.0 - 1.0;
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}
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inline half value(float2 center, float x, float y) {
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return tex2D(_LastFrame, center + float2(x, y)).r;
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}
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fixed4 frag (v2f i) : SV_Target
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{
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if(_ProjectionParams.z > 1) discard;
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const float resolution = 512.0;
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const float d = 1.0 / resolution;
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// Defines RADIUS Radius Kernel total_max
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#include "lenia_generated_kernel.cginc"
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float total = 0.0;
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[unroll(RADIUS)]
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for (int y = 0; y < Radius; y++) {
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[unroll(RADIUS)]
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for (int x = 1; x <= Radius; x++) {
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const float xx = (float)x * d;
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const float yy = (float)y * d;
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total += value(i.uv, xx, yy) * Kernel[y][x-1];
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total += value(i.uv, -yy, xx) * Kernel[y][x-1];
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total += value(i.uv, -xx, -yy) * Kernel[y][x-1];
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total += value(i.uv, yy, -xx) * Kernel[y][x-1];
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}
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}
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// */
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/*
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float total_max = 0;
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float total = 0;
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for (int x = -Radius; x <= Radius; x++) {
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for (int y = -Radius; y <= Radius; y++) {
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float dist = sqrt(x*x+y*y);
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float kval = kernel(dist);
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total_max += kval;
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total += value(i.uv, x*d, y*d) * kval;
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}
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}
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// */
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float old_state = value(i.uv, 0.0, 0.0) ;
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float count = total / total_max;
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float state = activation(count) * _Speed + old_state;
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state = clamp(state, 0, 1);
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// kernel visualization: lookup table (SLOW)
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// float k = 0;
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// {
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// float2 p = (i.uv - 0.5 ) * resolution;
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// p = floor(p);
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// if (p.x > 0 && p.y >= 0) {
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// k = Kernel[p.y][p.x-1];
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// } else if (p.x <= 0 && p.y > 0) {
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// k = Kernel[-p.x][p.y-1];
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// } else if (p.x < 0 && p.y <= 0) {
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// k = Kernel[-p.y][-p.x-1];
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// } else if (p.x >= 0 && p.y < 0) {
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// k = Kernel[p.x][-p.y-1];
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// }
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// }
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// kernel visualisation: real size
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// float2 p = (i.uv - 0.5) * resolution;
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// float k = kernel(length(p)) * (max(abs(p.x), abs(p.y)) <= _Radius);
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// kernel visualisation: fill square
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// float k = kernel(length(i.uv - 0.5) * _Radius * 2);
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// float a = activation(i.uv.x);
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// float4 col = float4(state, k, a, 1);
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float4 col = float4(state, i.uv.x * state, i.uv.y * state, 1);
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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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