52 lines
1.2 KiB
Rust
52 lines
1.2 KiB
Rust
// Follows this algorithm:
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// https://www.scratchapixel.com/lessons/procedural-generation-virtual-worlds/procedural-patterns-noise-part-1/simple-pattern-examples.html
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use rand::RngCore;
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use crate::image::{Image, Pixel};
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use crate::value_noise::ValueNoise;
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use crate::vec2::Vec2;
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pub fn generate_turbulence(
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width: usize,
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height: usize,
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rng: impl RngCore,
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) -> Image {
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let mut noise_map = vec![0.0; width * height];
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let noise = ValueNoise::new(rng);
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let frequency = 0.02;
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let frequency_mult = 1.8;
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let amplitude_mult = 0.35;
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let num_layers = 5;
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let mut max_noise_val = 0.0f64;
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for j in 0..height {
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for i in 0..width {
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let mut noise_point = Vec2::new(i as f64, j as f64) * frequency;
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let mut amplitude = 1.0;
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for _ in 0..num_layers {
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noise_map[j * width + i] =
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(2.0 * noise.eval(noise_point) - 1.0).abs() * amplitude;
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noise_point = noise_point * frequency_mult;
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amplitude *= amplitude_mult;
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}
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max_noise_val = max_noise_val.max(noise_map[j * width + i]);
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}
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}
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let data = noise_map
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.into_iter()
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.map(|f| {
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let v = (f / max_noise_val * 192.0 + 32.0).floor() as u8;
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Pixel(v, v, v)
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})
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.collect();
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Image {
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width,
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height,
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data,
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}
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}
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