int rand_gen(in int n) {
	n = (n << 13) ^ n; 
	return (n * (n*n*15731+789221) + 1376312589) & 0x7fffffff;
}

float rand_float(inout int n) {
	n = rand_gen(n);
	return float(n) / float(0x7fffffff);
}

void rand_mix(inout int n, int v) {
	n = rand_gen(n ^ v);
}