add draw_circle

src/drawing.rs

@@ -0,0 +1,9 @@
+use std::f64;
+
+  pub fn draw_circle(center: (f64, f64), radius: f64, context: &web_sys::CanvasRenderingContext2d) {
+    let (x, y) = center;
+    context.move_to(x+radius, y);
+    context
+      .arc(x, y, radius, 0.0, f64::consts::PI * 2.0)
+      .unwrap();
+  }

src/lib.rs

@@ -1,6 +1,6 @@
-use std::f64;
 use wasm_bindgen::prelude::*;
 use wasm_bindgen::JsCast;
+pub mod drawing;
 
 #[wasm_bindgen(start)]
 pub fn start() {
@@ -20,21 +20,9 @@ pub fn start() {
 
   context.begin_path();
 
-// arc(x, y, radius, startAngle, endAngle, counterclockwise)
-// Draws an arc which is centered at (x, y) position with radius r starting at startAngle and ending at endAngle going in the given direction indicated by counterclockwise (defaulting to clockwise).
-  context
-    .arc(75.0, 75.0, 50.0, 0.0, f64::consts::PI * 2.0)
-    .unwrap();
-
-  context.move_to(110.0, 75.0);
-  context
-    .arc(75.0, 75.0, 35.0, 0.0, f64::consts::PI)
-    .unwrap();
-  
-  context.move_to(65.0, 65.0);
-  context
-    .arc(60.0, 65.0, 5.0, 0.0, f64::consts::PI * 2.0)
-    .unwrap();
+  drawing::draw_circle((75.0, 75.0), 70.0, &context);
+  drawing::draw_circle((75.0, 75.0), 35.0, &context);
+  drawing::draw_circle((60.0, 65.0), 5.0, &context);
 
   context.stroke();
 }