Build canvas painter

monika · monika · commit a1064df0d188 · 2017-01-13T15:08:02.000-08:00
diff --git a/08 - Fun with HTML5 Canvas/index-START.html b/08 - Fun with HTML5 Canvas/index-START.html
@@ -7,6 +7,83 @@
 <body>
 <canvas id="draw" width="800" height="800"></canvas>
 <script>
+
+	// Define Constants
+	const canvas = document.querySelector("#draw");
+	const ctx = canvas.getContext("2d");
+
+	// Resize Canvas
+	canvas.width = window.innerWidth;
+	canvas.height = window.innerHeight;
+
+	// Set Defaults
+	ctx.strokeStyle = "#f00";
+	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;
+
+		console.log(e);
+
+		ctx.strokeStyle = `hsl(${hue}, 100%, 50%)`;
+		ctx.lineWidth = hue;
+		ctx.beginPath();
+		ctx.moveTo(lastX, lastY);
+		ctx.lineTo(e.offsetX, e.offsetY);
+		ctx.stroke();
+
+		lastX = e.offsetX;
+		lastY = e.offsetY;
+
+		hue++;
+
+		if( hue >= 360 ){
+
+			hue = 0;
+		}
+
+		if( ctx.lineWidth >= 100 || ctx.lineWidth <= 1) {
+
+			direction = !direction;
+
+		}
+
+		if( direction ){ 
+
+			ctx.lineWidth++;
+
+		} else { 
+
+			ctx.lineWidth--;
+
+		}
+
+	}
+
+	// Drawing Events
+	canvas.addEventListener('mousedown', (e) => {
+
+		isDrawing = true
+
+		lastX = e.offsetX;
+		lastY = e.offsetY;
+
+	});
+
+	canvas.addEventListener('mousemove', draw);
+	canvas.addEventListener('mouseup', () => isDrawing = false);
+	canvas.addEventListener('mouseout', () => isDrawing = false);
+
 </script>
 
 <style>
