Wikipedia method

mas/fractals/mandel/src/main.rs

@@ -26,25 +26,9 @@ fn main() {
     canvas.clear();
     canvas.present();
 
+    mandel::mandelbrot(&mut canvas, width, height, depth);
+    canvas.present();
 
-    let (mut dx, mut dy) = (xr[0], yr[0]);
-    let (mut x, mut y) = (0.0, 0.0);
-    let col: Color; // color buffer
-    while dx <= xr[1] {
-        dy = yr[0];
-        while dy <= yr[1] {
-            let col: Color = mandel::get_point_color(dx, dy, depth); 
-            y = dy*scale + (height as f32)/2.0;
-            x = dx*scale + (width as f32)/2.0;
-
-            // render pixel
-            render::set_pixel(&mut canvas, x as i32, y as i32, col);
-            println!("({dx} {dy}) - {x} {y}: {col:?}");
-            dy += theta;
-        }
-        dx += theta;
-        canvas.present();
-    }
     println!("Post mandel render");
 
     let mut event_pump = ctx.event_pump().unwrap();
@@ -61,7 +45,5 @@ fn main() {
 
     }
     ::std::thread::sleep(Duration::new(0, 1_000_000_000u32 / 60));
-    let mut coltest: Color = mandel::get_point_color(0.0, 1.0, depth);
-    println!("{coltest:?}");
 }
 

mas/fractals/mandel/src/mandel.rs

@@ -1,5 +1,8 @@
+use crate::render::set_pixel;
+
 use num::complex::Complex64;
 use sdl2::pixels::Color;
+use sdl2::render::Canvas;
 
 /*
 #[derive(Debug)]
@@ -38,7 +41,15 @@ pub fn get_point_color(x: f32, y: f32, depth: u64) -> Color {
     }
 }
 
-pub fn mandelbrot(w: u32, h: u32) -> Canvas {
+pub fn get_col(i: u32, max_iter: u32) -> Color {
+    if i > max_iter || i == 255 {
+        return Color::RGB(255, 255, 255);
+    } else {
+        return Color::RGB(i as u8, i as u8, i as u8);
+    }
+}
+
+pub fn mandelbrot(canvas: &mut Canvas<sdl2::video::Window>, w: u32, h: u32, depth: u32) {
 
     /*
 for each pixel (Px, Py) on the screen do
@@ -59,9 +70,23 @@ for each pixel (Px, Py) on the screen do
 
        */
 
+    let (mut x, mut y) = (0.0, 0.0);
+
     for dx in 0..w {
+        let x0 = ((dx as f32) / (w as f32)) * 3.5 - 2.5;
         for dy in 0..h {
+            let y0 = ((dy as f32) / (h as f32)) * 2.0 - 1.0;
+
+            let mut i: u32 = 0;
             
+            while i < depth && x*x + y*y <= 4.0 {
+                let xtemp = x*x - y*y + x0;
+                y = 2.0*x*y + y0;
+                x = xtemp;
+                i += 1;
+            }
+            let col = get_col(i, depth);
+            set_pixel(canvas, dx as i32, dy as i32, col);
         }
     }
 }