[cpu_shaders][flatten] Fix clippy warnings

src/cpu_shader/flatten.rs

@@ -332,7 +332,7 @@ fn flatten_arc(
     let n_lines = if theta <= ROBUST_EPSILON {
         MAX_LINES
     } else {
-        MAX_LINES.min((6.2831853 / theta).ceil() as u32)
+        MAX_LINES.min((std::f32::consts::TAU / theta).ceil() as u32)
     };
 
     let th = angle / (n_lines as f32);
@@ -364,7 +364,7 @@ fn draw_cap(
 ) {
     if cap_style == Style::FLAGS_CAP_BITS_ROUND {
         flatten_arc(
-            path_ix, cap0, cap1, point, 3.1415927, transform, line_ix, lines, bbox,
+            path_ix, cap0, cap1, point, std::f32::consts::PI, transform, line_ix, lines, bbox,
         );
         return;
     }
@@ -469,7 +469,7 @@ fn read_i16_point(ix: u32, pathdata: &[u32]) -> Vec2 {
     let raw = pathdata[ix as usize];
     let x = (((raw << 16) as i32) >> 16) as f32;
     let y = ((raw as i32) >> 16) as f32;
-    return Vec2::new(x, y);
+    Vec2 { x, y }
 }
 
 #[derive(Debug)]