cvr-props/Assets/automata/ElementaryCA/elementary_ca.shader
2023-09-22 21:24:21 +02:00

73 lines
1.2 KiB
GLSL

Shader "CrispyPin/elementary_ca"
{
Properties
{
[NoScaleOffset]
_LastFrame ("Render texture", 2D) = "white" {}
_Rule("Rule", Integer) = 110
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#define WIDTH 256
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
texture2D _LastFrame;
int _Rule;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}
inline int state(uint2 p, int dx, int dy)
{
const uint x = (p.x + dx) % WIDTH;
const uint y = (p.y + dy) % WIDTH;
return _LastFrame[uint2(x, y)].b > 0.1;
}
float3 frag (v2f i) : SV_Target
{
if(_ProjectionParams.z > 1) discard;
const uint2 p = i.uv * WIDTH;
if (p.y == WIDTH-1) {
return state(p, 0, 0);
}
int permutation =
(state(p, -1, 1) << 2) |
(state(p, 0, 1) << 1) |
state(p, 1, 1);
float next = (_Rule >> permutation) & 1;
return float3(i.uv * next, next * (_SinTime.y * 0.4 + 0.6));
}
ENDCG
}
}
}