Nathan Vegdahl
085d1d655e
This version of Sobol implements both Owen scrambling and index permutation, allowing for multiple statistically independent Sobol sequences.
30 lines
757 B
Rust
30 lines
757 B
Rust
pub fn hash_u32(n: u32, seed: u32) -> u32 {
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let mut hash = n;
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for _ in 0..3 {
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hash = hash.wrapping_mul(0x736caf6f);
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hash ^= hash.wrapping_shr(16);
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hash ^= seed;
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}
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hash
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}
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pub fn hash_u64(n: u64, seed: u64) -> u64 {
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let mut hash = n;
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for _ in 0..4 {
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hash = hash.wrapping_mul(32_416_190_071 * 314_604_959);
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hash ^= hash.wrapping_shr(32);
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hash ^= seed;
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}
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hash
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}
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/// Returns a random float in [0, 1] based on 'n' and a seed.
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/// Generally use n for getting a bunch of different random
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/// numbers, and use seed to vary between runs.
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pub fn hash_u32_to_f32(n: u32, seed: u32) -> f32 {
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const INV_MAX: f32 = 1.0 / std::u32::MAX as f32;
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hash_u32(n, seed) as f32 * INV_MAX
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}
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