solution wesbos#8

rustamyusupov · rustamyusupov · commit e1fea6006f9b · 2017-01-05T14:42:25.000+05:00
diff --git a/08 - Fun with HTML5 Canvas/index-START.html b/08 - Fun with HTML5 Canvas/index-START.html
@@ -7,6 +7,51 @@
 <body>
 <canvas id="draw" width="800" height="800"></canvas>
 <script>
+  const canvas = document.querySelector('#draw');
+  const ctx = canvas.getContext('2d');
+
+  canvas.width = window.innerWidth;
+  canvas.height = window.innerHeight;
+
+  ctx.strokeStyle = '#BADA55';
+  ctx.lineJoin = 'round';
+  ctx.lineCap = 'round';
+
+  let isDrawing = false;
+  let lastX = 0;
+  let lastY = 0;
+  let hue = 0;
+  let direction = true;
+
+  function draw(evt) {
+    if (!isDrawing) return;
+
+    ctx.strokeStyle = `hsl(${hue}, 100%, 50%)`;
+
+    ctx.beginPath();
+    ctx.moveTo(lastX, lastY);
+    ctx.lineTo(evt.offsetX, evt.offsetY);
+    ctx.stroke();
+
+    [lastX, lastY] = [evt.offsetX, evt.offsetY];
+
+    hue++;
+    if (hue >= 360) hue = 0;
+
+    if (ctx.lineWidth >= 100 || ctx.lineWidth <= 1) direction = !direction;
+
+    if (direction) ctx.lineWidth++;
+    else ctx.lineWidth--;
+  }
+
+  addEventListener('mousemove', draw);
+  addEventListener('mousedown', (evt) => {
+    isDrawing = true;
+    [lastX, lastY] = [evt.offsetX, evt.offsetY];
+  });
+
+  addEventListener('mouseup', () => isDrawing = false);
+  addEventListener('mouseout', () => isDrawing = false);
 </script>
 
 <style>
