noiseHash2 function Noise
Bit-exact hashed value for the integer lattice cell (x, y).
Pure 32-bit integer math, guaranteed to produce the same signed 32-bit
result as the GLSL NoiseHash2(ivec2(x, y), seed) on every backend (and
between native and web Dart). Use it for decisions that must never
disagree between the CPU and a shader.
Implementation
int noiseHash2(int seed, int x, int y) =>
_hash2(_i32(seed), _i32(_i32(x) * _primeX), _i32(_i32(y) * _primeY));