code along wesbos#8 fun with html canvas

mmoroney01 · mmoroney01 · commit 8f1ceacf0fda · 2018-05-22T10:56:59.000-05:00
diff --git a/08 - Fun with HTML5 Canvas/index-START.html b/08 - Fun with HTML5 Canvas/index-START.html
@@ -7,6 +7,54 @@
 <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';
+ctx.lineWidth = 100;
+
+let isDrawing = false;
+let lastX = 0;
+let lastY = 0;
+let hue = 0;
+let direction = true;
+
+function draw(e) {
+  if(!isDrawing) return;
+  ctx.strokeStyle = `hsl(${hue}, 100%, 50%)`;
+  ctx.beginPath();
+  ctx.moveTo(lastX, lastY);
+  ctx.lineTo(e.offsetX, e.offsetY);
+  ctx.stroke();
+  [lastX, lastY] = [e.offsetX, e.offsetY];
+
+  hue++;
+
+  if(hue >= 360){
+  	hue = 0;
+  }
+  if(ctx.lineWidth >= 100 || ctx.lineWidth <= 1){
+  	direction = !direction;
+  }
+  if(direction){
+    ctx.lineWidth++;
+  } else {
+  	ctx.lineWidth--;
+  }
+}
+
+canvas.addEventListener('mousedown', (e) => {
+	isDrawing = true;
+	[lastX, lastY] = [e.offsetX, e.offsetY];
+});
+
+canvas.addEventListener('mousemove', draw);
+canvas.addEventListener('mouseup', () => isDrawing = false);
+canvas.addEventListener('mouseout', () => isDrawing = false);
+
 </script>
 
 <style>
