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mandelbrot
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chore: add colours present in olc's video on mandelbrot

This commit is contained in:
Rekai Nyangadzayi Musuka 2021-04-07 00:36:52 -05:00
parent 10c789f569
commit 256aee7503
2 changed files with 27 additions and 28 deletions
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4
src/main.rs
View File

@ -138,13 +138,9 @@ fn mandelbrot_render_system(
let y = ((-1.0 * z) - v, (1.0 * z) - v);
let bounds = Bounds::new(x, y);
let start = Instant::now();
texture
.data
.copy_from_slice(fractal.scaled_image(bounds, limit));
let _diff = Instant::now() - start;
}
}
}

51
src/mandelbrot.rs
View File

@ -65,52 +65,56 @@ impl Default for Mandelbrot {
impl Mandelbrot {
pub fn image(&mut self) -> &[u8] {
let limit = DEFAULT_ITERATION_LIMIT as f64;
let error = f64::EPSILON;
self.frame_buffer
.par_chunks_mut(4)
.enumerate()
.for_each(|(i, buf)| {
let iters = Self::escape_time(i, DEFAULT_BOUNDS, DEFAULT_ITERATION_LIMIT);
let normalized = iters / limit;
let h = normalized * 350.0;
let v = if (iters - limit).abs() < error {
0.0
} else {
1.0
};
buf.copy_from_slice(&Self::hsv_to_rgb(h, 1.0, v));
buf.copy_from_slice(&Self::default_colours(iters, limit))
});
self.frame_buffer.as_ref()
}
pub fn scaled_image(&mut self, bounds: Bounds, limit: u32) -> &[u8] {
let error = f64::EPSILON;
self.frame_buffer
.par_chunks_mut(4)
.enumerate()
.for_each(|(i, buf)| {
let iters = Self::escape_time(i, bounds, limit);
let limit = limit as f64;
let normalized = iters / limit;
let h = normalized * 350.0;
let v = if (iters - limit).abs() < error {
0.0
} else {
1.0
};
buf.copy_from_slice(&Self::hsv_to_rgb(h, 1.0, v))
buf.copy_from_slice(&Self::default_colours(iters, limit))
});
self.frame_buffer.as_ref()
}
fn olc_colours(iters: f64) -> [u8; 4] {
let a = 0.1;
let red = (0.5 * (a * iters).sin() + 0.5) * 255.0;
let green = (0.5 * (a * iters + 2.094).sin() + 0.5) * 255.0;
let blue = (0.5 * (a * iters + 4.188).sin() + 0.5) * 255.0;
[red as u8, green as u8, blue as u8, 0xFF]
}
fn default_colours(iters: f64, limit: f64) -> [u8; 4] {
let normal = iters / limit;
let h = normal * 350.0;
let v = if (iters - limit).abs() < f64::EPSILON {
0.0
} else {
1.0
};
Self::hsv_to_rgb(h, 1.0, v)
}
fn escape_time(i: usize, bounds: Bounds, limit: u32) -> f64 {
let point = Coordinate::new(i % TEXTURE_WIDTH, i / TEXTURE_WIDTH);
let c = point.into_complex(bounds);
@ -118,7 +122,6 @@ impl Mandelbrot {
Self::count_iterations(c, limit)
}
#[inline]
fn hsv_to_rgb(h: f64, s: f64, v: f64) -> [u8; 4] {
let c = v * s;
let x = c * (1.0 - (((h / 60.0) % 2.0) - 1.0).abs());
@ -167,6 +170,8 @@ impl Mandelbrot {
count += 1;
}
// For a performance booth (with the consequence of a less smooth gradient)
// just return count instead of doing all this math on it
if count < limit {
(count as f64 + 1.0) - z.norm().ln().ln() / 2f64.ln()
} else {
@ -174,7 +179,6 @@ impl Mandelbrot {
}
}
#[inline]
fn scale_width(x: usize, bounds: (f64, f64)) -> f64 {
// const X_MIN: f64 = -2.5;
// const X_MAX: f64 = 1.0;
@ -182,7 +186,6 @@ impl Mandelbrot {
bounds.0 + ((bounds.1 - bounds.0) * (x as f64 - 0.0)) / TEXTURE_WIDTH as f64 - 0.0
}
#[inline]
fn scale_height(y: usize, bounds: (f64, f64)) -> f64 {
// const Y_MIN: f64 = -1.0;
// const Y_MAX: f64 = 1.0;