Cargo.toml

[package]
name = "MandelbrotImage"
version = "0.1.0"
authors = ["Johnathan Walker <jhwalking0@gmail.com>"]

[dependencies]
image = "*"
num = "*"

main.rs

extern crate image;
extern crate num;

use std::fs::File;
use std::path::Path;

use num::Complex;

// a function which takes a borrowed Complex<f32> and checks if its within
// the bounds of the mandelbrot set
fn in_mandel(p : &Complex<f32>) -> bool {
    p.norm_sqr() < 4.0
}

// takes in an iteration limit and a borrowed Complex<f32>
// preforms z = z^2 + p until it reaches the iteration limit or
// it goes out of bounds 
fn iter(limit : usize, p : &Complex<f32>) -> usize {

    let mut i : usize = 0;
    let mut z : Complex<f32> = Complex::new(0.0, 0.0);
    while i < limit && in_mandel(&z) {
        z = z.powf(2.0) + p;
        i += 1;
    };

    i
}

// really shitty color pallet just uses the iteration count as a color
// looks awful
fn color(i : usize) -> [u8;1] {
    [ i as u8 ]
}

// main function o boi
fn main() {

    // some dumb x and y offsets with variables
    let x : f32 = 1.0;
    let y : f32 = 0.0;
    let scale : f32 = 0.005;

    // reserves the space for the image in ram of size 1000x1000
    let mut image = image::ImageBuffer::new(1000u32, 1000u32);

    // showing off the beautiful iterator trait
    //  enumerate_pixels_mut() returns an iterator of the x, y, and reference to
    //  the pixels
    for (re, im, p) in image.enumerate_pixels_mut() {
        // this is dumb shit don't do this in practice
        // just shoving functions into one another
        // you can use some libs like command to have pipelines but I cba
        *p = image::Luma(color(iter(
                    255
                  , &Complex::new( (re as f32 - 500.0 - x) * scale
                                 , (im as f32 - 500.0 - y) * scale
                                  ))));
    };

    // creating the file reference
    let ref mut fout = File::create(&Path::new("test.png")).unwrap();

    // writing the image to the file and throwing away the result
    let _ = image::ImageLuma8(image).save(fout, image::PNG);

}