From eb6207e1198e7a4b06531e70baefc0a32f3cf407 Mon Sep 17 00:00:00 2001
From: "0m.ax" <git@0m.ax>
Date: Sat, 19 Jul 2025 02:19:11 +0200
Subject: [PATCH] squircle

---
 src/main.rs | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index d00d10e..87307df 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -119,6 +119,80 @@ impl Drawable for BouncingImage {
     }
 }
 
+struct Circle {
+   x: u32,
+   y: u32,
+   radius: i32
+}
+impl Circle {
+
+    fn new(x:u32, y: u32,radius:i32) -> Self {
+        Circle {
+         x,
+         y,
+         radius   
+        }
+    }    
+
+    /// This exploits the eight-way symmetry of a circle.
+    fn draw_circle_octants(&mut self, display: &mut Display, cx: u16, cy: u16, x: u16, y: u16, r: u8, g: u8, b: u8) {
+        display.set_pixel(cx + x, cy + y, r, g, b);
+        display.set_pixel(cx - x, cy + y, r, g, b);
+        display.set_pixel(cx + x, cy - y, r, g, b);
+        display.set_pixel(cx - x, cy - y, r, g, b);
+        display.set_pixel(cx + y, cy + x, r, g, b);
+        display.set_pixel(cx - y, cy + x, r, g, b);
+        display.set_pixel(cx + y, cy - x, r, g, b);
+        display.set_pixel(cx - y, cy - x, r, g, b);
+    }
+
+    /// Draws a circle using the Midpoint Circle Algorithm.
+    ///
+    /// # Arguments
+    /// * `center_x`: The x-coordinate of the circle's center.
+    /// * `center_y`: The y-coordinate of the circle's center.
+    /// * `radius`: The radius of the circle. Must be non-negative.
+    /// * `r`, `g`, `b`: The RGB color components for the circle.
+    pub fn draw_circle(&mut self, display: &mut Display, center_x: u32, center_y: u32, radius: i32, r: u8, g: u8, b: u8) {
+        if radius < 0 {
+            // Or return an error: Err("Radius cannot be negative".into())
+            return;
+        }
+
+        let mut x = 0;
+        let mut y = radius;
+        // Initial decision parameter
+        let mut d = 3 - 2 * radius;
+
+        // Iterate through the first octant and draw points in all 8 octants
+        while y >= x {
+            self.draw_circle_octants(display,center_x.try_into().unwrap(), center_y.try_into().unwrap(), x.try_into().unwrap(), y.try_into().unwrap(), r, g, b);
+
+            x += 1;
+
+            // Update the decision parameter
+            if d > 0 {
+                y -= 1;
+                d = d + 4 * (x - y) + 10;
+            } else {
+                d = d + 4 * x + 6;
+            }
+        }
+    }
+
+}
+impl Drawable for Circle {
+
+    fn rate(&self) -> u32 {
+        1
+    }
+
+       /// Helper method to draw the 8 symmetric points for a given (x, y) offset.
+    fn draw_and_move(&mut self, display: &mut Display) {
+     self.draw_circle(display,self.x,self.y,self.radius,255,255,255);   
+    }   
+}
+
 /// Manages the connection and data sent to the display.
 struct Display {
     socket: UdpSocket,
@@ -202,6 +276,7 @@ fn main() {
         Box::new(BouncingImage::new("images/spade.png", 32, -12, 1, 0, 0)),
         Box::new(BouncingImage::new("images/dvdvideo.png", 20, 6, 5, 1000, 800)),
         Box::new(BouncingImage::new("images/hackaday.png", 40, 18, 3, 500, 800)),
+        Box::new(Circle::new(1920/2,1080/2,128))
     ];
 
     let mut display = Display::new(DISPLAY_HOST, DISPLAY_PORT);