Pixel-Composer/scripts/perlin_noise/perlin_noise.gml

33 lines
697 B
Plaintext
Raw Normal View History

2022-01-13 05:24:03 +01:00
function __random2 (_x, _y, _s) {
random_set_seed((_x + _y) * (_x + _y + 1) / 2 + _y + _s);
return random(1);
}
function __noise(_x, _y, _seed) {
var fl_x = floor(_x);
var fl_y = floor(_y);
var a = __random2(fl_x + 0, fl_y + 0, _seed);
var b = __random2(fl_x + 1, fl_y + 0, _seed);
var c = __random2(fl_x + 0, fl_y + 1, _seed);
var d = __random2(fl_x + 1, fl_y + 1, _seed);
return lerp(lerp(a, b, _x - fl_x), lerp(c, d, _x - fl_x), _y - fl_y);
}
function perlin_noise(_x, _y, _amp, _seed) {
var res = 0;
var maxx = 0;
var mulp = 0.5;
repeat(_amp) {
res += __noise(_x, _y, _seed) * mulp;
maxx += mulp;
_x /= 2;
_y /= 2;
mulp *= 0.5;
}
return res / maxx;
}