feat: working interactive mandelbrot

todo: fix the zoom issue (not completely centered)

.cargo/config.toml

@@ -0,0 +1,22 @@
+# Rename this file to `config.toml` to enable "fast build" configuration. Please read the notes below.
+
+# NOTE: For maximum performance, build using a nightly compiler
+# If you are using rust stable, remove the "-Zshare-generics=y" below.
+
+[target.x86_64-unknown-linux-gnu]
+linker = "/usr/bin/clang"
+rustflags = ["-Clink-arg=-fuse-ld=lld", "-Zshare-generics=y"]
+
+# NOTE: you must manually install https://github.com/michaeleisel/zld on mac. you can easily do this with the "brew" package manager:
+# `brew install michaeleisel/zld/zld`
+[target.x86_64-apple-darwin]
+rustflags = ["-C", "link-arg=-fuse-ld=/usr/local/bin/zld", "-Zshare-generics=y", "-Zrun-dsymutil=no"]
+
+[target.x86_64-pc-windows-msvc]
+linker = "rust-lld.exe"
+rustflags = ["-Zshare-generics=y"]
+
+# Optional: Uncommenting the following improves compile times, but reduces the amount of debug info to 'line number tables only'
+# In most cases the gains are negligible, but if you are on macos and have slow compile times you should see significant gains.
+#[profile.dev]
+#debug = 1

.gitignore

@@ -1,3 +1,4 @@
 /target
 /.vscode
 test.png
+/assets

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+bevy = "0.3"
 image = "0.23"
 num-complex = "0.3"
 rayon = "1.5"

src/lib.rs

@@ -0,0 +1,2 @@
+pub use mandelbrot::Mandelbrot;
+mod mandelbrot;

src/main.rs

@@ -1,110 +1,107 @@
-use image::{ImageBuffer, Rgb, RgbImage};
-use num_complex::Complex;
-use rayon::prelude::*;
-
-const IMG_WIDTH: usize = 1920;
-const IMG_HEIGHT: usize = 1080;
-const MAX_ITERATIONS: u16 = 1000;
+use bevy::{prelude::*, render::texture::TextureFormat};
+use mandelbrot::Mandelbrot;
+use std::time::Instant;
 
 fn main() {
-    let mut img: RgbImage = ImageBuffer::new(IMG_WIDTH as u32, IMG_HEIGHT as u32);
-
-    escape_time(&mut img);
-
-    img.save("test.png").unwrap();
+    // Mandelbrot::escape_time_image();
+    App::build()
+        .add_plugins(DefaultPlugins)
+        .add_resource(SpriteScale::default())
+        .add_startup_system(png_startup.system())
+        .add_system(mandelbrot_render_system.system())
+        .add_system(mandelbrot_input_scale_system.system())
+        .run();
 }
 
-fn escape_time(img: &mut ImageBuffer<Rgb<u8>, Vec<u8>>) {
-    let mut mandelbrot: Vec<u16> = vec![0; IMG_HEIGHT * IMG_WIDTH];
+struct SpriteScale {
+    zoom: f64,
+    horiz: f64,
+    verti: f64,
+    step: f64,
+}
 
-    mandelbrot
-        .par_iter_mut()
-        .enumerate()
-        .for_each(|(i, value)| {
-            let px = i % IMG_WIDTH;
-            let py = i / IMG_WIDTH;
-
-            let c = coords_to_complex(px, py);
-
-            *value = calc_num_iterations(c);
-        });
-
-    for (px, py, pixel) in img.enumerate_pixels_mut() {
-        let i = px as usize + IMG_WIDTH * py as usize;
-        let num_iterations = mandelbrot[i];
-
-        match find_colour(num_iterations) {
-            Colour::White => *pixel = Rgb([0x00, 0x00, 0x00]),
-            Colour::Black => *pixel = Rgb([0xFF, 0xFF, 0xFF]),
-            Colour::Gray => *pixel = Rgb([0xAA, 0xAA, 0xAA]),
+impl Default for SpriteScale {
+    fn default() -> Self {
+        Self {
+            zoom: 1.0,
+            horiz: 0.0,
+            verti: 0.0,
+            step: 0.01,
         }
     }
 }
 
-enum Colour {
-    White,
-    Black,
-    Gray,
-}
+fn mandelbrot_input_scale_system(
+    input: Res<Input<KeyCode>>,
+    mut scale: ResMut<SpriteScale>,
+    // camera: Res<Camera>,
+) {
+    let zoom = input.pressed(KeyCode::Q) as i8 - input.pressed(KeyCode::E) as i8;
+    let horizontal = input.pressed(KeyCode::D) as i8 - input.pressed(KeyCode::A) as i8;
+    let vertical = input.pressed(KeyCode::W) as i8 - input.pressed(KeyCode::S) as i8;
+    let step_mod = input.pressed(KeyCode::R) as i8 - input.pressed(KeyCode::F) as i8;
 
-fn find_colour(iteration: u16) -> Colour {
-    match iteration {
-        MAX_ITERATIONS => Colour::Black,
-        other => match other % 2 {
-            0 => Colour::White,
-            1 => Colour::Gray,
-            _ => unreachable!(),
-        },
+    scale.step += (scale.step / 10.0) * step_mod as f64;
+    scale.verti += scale.step * vertical as f64;
+    scale.horiz += scale.step * horizontal as f64;
+    scale.zoom += scale.step * zoom as f64;
+
+    if scale.zoom < 0.0 {
+        // We can't go below 0
+        scale.zoom -= scale.step * zoom as f64;
     }
 }
 
-fn calc_num_iterations(c: Complex<f64>) -> u16 {
-    let mut z: Complex<f64> = Complex::new(0.0, 0.0);
-    let mut num_iterations: u16 = 0;
+const X_BOUNDS: (f64, f64) = (-2.5, 1.0);
+const Y_BOUNDS: (f64, f64) = (-1.0, 1.0);
 
-    for i in 0..MAX_ITERATIONS {
-        if z.norm_sqr() > 4.0 {
-            num_iterations = i;
-            break;
+fn mandelbrot_render_system(
+    materials: Res<Assets<ColorMaterial>>,
+    mut textures: ResMut<Assets<Texture>>,
+    scale: Res<SpriteScale>,
+    mut query: Query<(&mut Mandelbrot, &Handle<ColorMaterial>)>,
+) {
+    for (mut fractal, handle) in query.iter_mut() {
+        if let Some(material) = materials.get(handle) {
+            if let Some(texture_handle) = &material.texture {
+                if let Some(texture) = textures.get_mut(texture_handle) {
+                    let z = scale.zoom;
+                    let h = scale.horiz;
+                    let v = scale.verti;
+
+                    let start = Instant::now();
+                    texture.data = fractal.generate_scaled_image(
+                        ((-2.5 * z) + h, (1.0 * z) + h),
+                        ((-1.0 * z) - v, (1.0 * z) - v),
+                    );
+                    let diff = Instant::now() - start;
+
+                    dbg!(z);
+                    dbg!(diff);
                 }
-
-        z = (z * z) + c;
             }
-
-    num_iterations
-}
-
-fn coords_to_complex(px: usize, py: usize) -> Complex<f64> {
-    Complex::new(scale_width(px), scale_height(py))
-}
-
-fn scale_width(px: usize) -> f64 {
-    const X_MIN: f64 = -2.5;
-    const X_MAX: f64 = 1.0;
-
-    X_MIN + ((X_MAX - X_MIN) * (px as f64 - 0.0)) / (IMG_WIDTH as f64 - 0.0)
-}
-
-fn scale_height(py: usize) -> f64 {
-    const Y_MIN: f64 = -1.0;
-    const Y_MAX: f64 = 1.0;
-
-    Y_MIN + ((Y_MAX - Y_MIN) * (py as f64 - 0.0)) / (IMG_HEIGHT as f64 - 0.0)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn scale_width_bounds() {
-        assert_eq!(scale_width(0), -2.5f64);
-        assert_eq!(scale_width(IMG_WIDTH), 1f64);
         }
-
-    #[test]
-    fn scale_height_bounds() {
-        assert_eq!(scale_height(0), -1f64);
-        assert_eq!(scale_height(IMG_HEIGHT), 1f64);
     }
 }
+
+fn png_startup(
+    mut commands: Commands,
+    asset_server: Res<AssetServer>,
+    mut materials: ResMut<Assets<ColorMaterial>>,
+) {
+    let texture_handle = asset_server.load("test.png");
+    commands
+        .spawn(Camera2dComponents::default())
+        .spawn(SpriteComponents {
+            material: materials.add(texture_handle.into()),
+            ..Default::default()
+        })
+        .with(Mandelbrot::new());
+}
+
+fn fractal_startup(mut commands: Commands) {
+    commands
+        .spawn(Camera2dComponents::default())
+        .spawn(SpriteComponents::default())
+        .with(Mandelbrot::new());
+}

src/mandelbrot.rs

@@ -0,0 +1,205 @@
+use image::{ImageBuffer, Rgb, RgbImage};
+use num_complex::Complex;
+use rayon::prelude::*;
+
+const MAX_ITERATIONS: u16 = 256;
+const IMG_WIDTH: usize = 1280;
+const IMG_HEIGHT: usize = 720;
+
+#[derive(Debug, Clone)]
+pub struct Mandelbrot {
+    iterations: Vec<u16>,
+}
+
+enum Colour {
+    White,
+    Black,
+    Gray,
+}
+
+impl Mandelbrot {
+    pub fn new() -> Self {
+        Mandelbrot {
+            iterations: vec![0; IMG_WIDTH * IMG_HEIGHT],
+        }
+    }
+
+    pub fn generate_image(&mut self) -> Vec<u8> {
+        // Create the image
+        // Pixel Format can be Rgba8UnormSrgb
+        self.escape_time();
+
+        let mut texture_buffer = vec![0; (IMG_WIDTH * IMG_HEIGHT) * 4];
+
+        for i in 0..texture_buffer.len() {
+            if i % 4 == 0 {
+                let iter_i = i / 4;
+                match Self::find_colour(self.iterations[iter_i]) {
+                    Colour::White => {
+                        texture_buffer[i] = 0x00;
+                        texture_buffer[i + 1] = 0x00;
+                        texture_buffer[i + 2] = 0x00;
+                        texture_buffer[i + 3] = 0xFF;
+                    }
+                    Colour::Black => {
+                        texture_buffer[i] = 0xFF;
+                        texture_buffer[i + 1] = 0xFF;
+                        texture_buffer[i + 2] = 0xFF;
+                        texture_buffer[i + 3] = 0xFF;
+                    }
+                    Colour::Gray => {
+                        texture_buffer[i] = 0xAA;
+                        texture_buffer[i + 1] = 0xAA;
+                        texture_buffer[i + 2] = 0xAA;
+                        texture_buffer[i + 3] = 0xFF;
+                    }
+                }
+            }
+        }
+
+        texture_buffer
+    }
+
+    pub fn generate_scaled_image(&mut self, x_bounds: (f64, f64), y_bounds: (f64, f64)) -> Vec<u8> {
+        let mut texture_buffer = vec![0; (IMG_WIDTH * IMG_HEIGHT) * 4];
+        self.iterations
+            .par_iter_mut()
+            .enumerate()
+            .for_each(|(i, value)| {
+                let px = i % IMG_WIDTH;
+                let py = i / IMG_WIDTH;
+
+                let c = Self::coords_to_complex(px, py, x_bounds, y_bounds);
+
+                *value = Self::calc_num_iterations(c);
+            });
+
+        for i in 0..texture_buffer.len() {
+            if i % 4 == 0 {
+                let iter_i = i / 4;
+                match Self::find_colour(self.iterations[iter_i]) {
+                    Colour::White => {
+                        texture_buffer[i] = 0x00;
+                        texture_buffer[i + 1] = 0x00;
+                        texture_buffer[i + 2] = 0x00;
+                        texture_buffer[i + 3] = 0xFF;
+                    }
+                    Colour::Black => {
+                        texture_buffer[i] = 0xFF;
+                        texture_buffer[i + 1] = 0xFF;
+                        texture_buffer[i + 2] = 0xFF;
+                        texture_buffer[i + 3] = 0xFF;
+                    }
+                    Colour::Gray => {
+                        texture_buffer[i] = 0xAA;
+                        texture_buffer[i + 1] = 0xAA;
+                        texture_buffer[i + 2] = 0xAA;
+                        texture_buffer[i + 3] = 0xFF;
+                    }
+                }
+            }
+        }
+
+        texture_buffer
+    }
+
+    fn escape_time(&mut self) {
+        self.iterations
+            .par_iter_mut()
+            .enumerate()
+            .for_each(|(i, value)| {
+                let px = i % IMG_WIDTH;
+                let py = i / IMG_WIDTH;
+
+                let c = Self::coords_to_complex(px, py, (-2.5, 1.0), (-1.0, 1.0));
+
+                *value = Self::calc_num_iterations(c);
+            });
+    }
+
+    pub fn escape_time_image() {
+        const IMG_WIDTH: usize = 1280;
+        const IMG_HEIGHT: usize = 720;
+
+        let mut img: RgbImage = ImageBuffer::new(IMG_WIDTH as u32, IMG_HEIGHT as u32);
+        let mut mandelbrot: Vec<u16> = vec![0; IMG_HEIGHT * IMG_WIDTH];
+
+        mandelbrot
+            .par_iter_mut()
+            .enumerate()
+            .for_each(|(i, value)| {
+                let px = i % IMG_WIDTH;
+                let py = i / IMG_WIDTH;
+
+                let c = Self::coords_to_complex(px, py, (-2.5, 1.0), (-1.0, 1.0));
+
+                *value = Self::calc_num_iterations(c);
+            });
+
+        for (px, py, pixel) in img.enumerate_pixels_mut() {
+            let i = px as usize + IMG_WIDTH * py as usize;
+            let num_iterations = mandelbrot[i];
+
+            match Self::find_colour(num_iterations) {
+                Colour::White => *pixel = Rgb([0x00, 0x00, 0x00]),
+                Colour::Black => *pixel = Rgb([0xFF, 0xFF, 0xFF]),
+                Colour::Gray => *pixel = Rgb([0xAA, 0xAA, 0xAA]),
+            }
+        }
+
+        img.save("assets/test.png").unwrap();
+    }
+
+    fn find_colour(iteration: u16) -> Colour {
+        match iteration {
+            MAX_ITERATIONS => Colour::Black,
+            other => match other % 2 {
+                0 => Colour::White,
+                1 => Colour::Gray,
+                _ => unreachable!(),
+            },
+        }
+    }
+
+    fn calc_num_iterations(c: Complex<f64>) -> u16 {
+        let mut z: Complex<f64> = Complex::new(0.0, 0.0);
+        let mut num_iterations: u16 = 0;
+
+        for i in 0..MAX_ITERATIONS {
+            if z.norm_sqr() > 4.0 {
+                num_iterations = i;
+                break;
+            }
+
+            z = (z * z) + c;
+        }
+
+        num_iterations
+    }
+
+    fn coords_to_complex(
+        px: usize,
+        py: usize,
+        x_bounds: (f64, f64),
+        y_bounds: (f64, f64),
+    ) -> Complex<f64> {
+        Complex::new(
+            Self::scale_width(px, x_bounds),
+            Self::scale_height(py, y_bounds),
+        )
+    }
+
+    fn scale_width(px: usize, x_bounds: (f64, f64)) -> f64 {
+        // const X_MIN: f64 = -2.5;
+        // const X_MAX: f64 = 1.0;
+
+        x_bounds.0 + ((x_bounds.1 - x_bounds.0) * (px as f64 - 0.0)) / IMG_WIDTH as f64 - 0.0
+    }
+
+    fn scale_height(py: usize, y_bounds: (f64, f64)) -> f64 {
+        // const Y_MIN: f64 = -1.0;
+        // const Y_MAX: f64 = 1.0;
+
+        y_bounds.0 + ((y_bounds.1 - y_bounds.0) * (py as f64 - 0.0)) / IMG_HEIGHT as f64 - 0.0
+    }
+}