Antialiasing kind of works on circles drawing each pixel individually

src/graphics/rectangle.rs

@@ -1,6 +1,31 @@
-
 use crate::wayland::shm::ShmPool;
 
+fn color_blend(col1: u32, col2: u32, diff: f64) -> u32 {
+    // TODO: Account for alpha channel
+    let r1 = (col1 & 0x00ff0000) >> 16;
+    let g1 = (col1 & 0x0000ff00) >> 8;
+    let b1 = col1 & 0x000000ff;
+    let r2 = (col2 & 0x00ff0000) >> 16;
+    let g2 = (col2 & 0x0000ff00) >> 8;
+    let b2 = col2 & 0x000000ff;
+    let r3 = if r1 < r2 {
+        r1 + ((r2 - r1) as f64 * diff) as u32
+    } else {
+        r1 - ((r1 - r2) as f64 * diff) as u32
+    };
+    let g3 = if g1 < g2 {
+        g1 + ((g2 - g1) as f64 * diff) as u32
+    } else {
+        g1 - ((g1 - g2) as f64 * diff) as u32
+    };
+    let b3 = if b1 < b2 {
+        b1 + ((b2 - b1) as f64 * diff) as u32
+    } else {
+        b1 - ((b1 - b2) as f64 * diff) as u32
+    };
+    return 0xff000000 + (r3 << 16) + (g3 << 8) + b3;
+}
+
 // l_row means local row and g_row means global row
 impl ShmPool {
 
@@ -30,14 +55,21 @@ impl ShmPool {
             self.write(&vec![color; w], g_row*self.width+x);
         }
     }
-    
+
-    // x and y are center of circle
+    pub fn shitty_circle(&mut self, x: usize, y: usize, radius: usize, color: u32) {
-    pub fn circle(&mut self, x: usize, y: usize, radius: usize, color: u32) {
+        for g_row in y-radius..y+radius+1 { 
-        for l_row in 0..radius { 
+            for g_col in x-radius..x+radius+1 { 
-            let x_diff = ((radius*radius - l_row*l_row) as f64).sqrt();
+                let l_row = y.abs_diff(g_row);
-            let mut row: Vec<u32> = vec![color; 2*x_diff as usize];
+                let l_col = y.abs_diff(g_col);
-            self.write(&row, (y+l_row)*self.width + x - x_diff as usize);
+                let distance = (((l_row*l_row)+(l_col*l_col)) as f64).sqrt();
-            self.write(&row, (y-l_row)*self.width + x - x_diff as usize);
+                let offset = g_row*self.width + g_col;
+                if (distance.floor() as usize) < radius {
+                    self.write_pixel(color, offset as isize);
+                } else if (distance.ceil() as usize) <= radius+1 {
+                    dbg!(distance);
+                    self.write_pixel(color_blend(color, self.read_pixel(offset), distance.fract()), offset as isize);
+                }
+            }
         }
     }
 }

src/wayland/wl_shm.rs

@@ -14,7 +14,7 @@ impl WlClient {
         self.shm_pool = Some(shm::ShmPool::new(width, height, self.current_id)?);
         self.shm_pool.as_mut().unwrap().write(&vec![0xffff0000; width * height], 0);
         self.shm_pool.as_mut().unwrap().rectangle(50, 50, 50, 50, 0xff00ff00);
-        self.shm_pool.as_mut().unwrap().circle(200, 200, 50, 0xff0000ff);
+        self.shm_pool.as_mut().unwrap().shitty_circle(200, 200, 20, 0xff0000ff);
         self.shm_pool.as_mut().unwrap().rounded_rectangle(400, 200, 200, 100, 14, 0xffffff00);
 
         let object = self.shm_id.ok_or(UnsetErr("shm_id".to_string()))?;