How to draw a circle in HTML5 canvas? (code example)
Canvas can be used to draw various graphics, so how to use HTML5 canvas to draw a circle? This article will introduce to you the method of drawing circles on HTML5 canvas. Let’s take a look at the specific content.
Let’s look at the example directly
The code is as follows
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title></title> <meta charset="utf-8" /> <script type="text/javascript"> function draw() { var canvas = document.getElementById('SimpleCanvas'); if ( ! canvas || ! canvas.getContext ) { return false; } var cx = 360; var cy = 400; var radius = 36; var context = canvas.getContext('2d'); context.beginPath(); context.arc(cx, cy, radius, 0, 2 * Math.PI, false); context.fillStyle = '#9fd9ef'; context.fill(); context.lineWidth = 1; context.strokeStyle = '#00477d'; context.stroke(); } </script> </head> <body onload="draw()" style="background-color:#D0D0D0;"> <canvas id="SimpleCanvas" width="640" height="480" style="background-color:#FFFFFF;"></canvas> <div>Canvas Demo</div> </body> </html>
Running results
Execute the above HTML file on the browser . The following effect will be displayed
Finally, the coordinates of the circle given by the arc() method are the center coordinates of the circle.
function draw() { var canvas = document.getElementById('SimpleCanvas'); if ( ! canvas || ! canvas.getContext ) { return false; } var cx = 360; var cy = 400; var radius = 36; var context = canvas.getContext('2d'); context.beginPath(); context.arc(cx, cy, radius, 0, 2 * Math.PI, false); context.fillStyle = '#9fd9ef'; context.fill(); context.lineWidth = 1; context.strokeStyle = '#00477d'; context.stroke(); context.beginPath(); context.moveTo(0, 0); context.lineTo(cx, cy); context.stroke(); }
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