< !DOCTYPE html >
< html >
< body >
< canvas id = "myCanvas"
width = "800"
height = "450"
style = "border:1px solid #d3d3d3;" >
< /canvas>
< function >
blueCircle.addEventListener("click", getClickPosition, false);
function getClickPosition(e) {
var xPosition = e.clientX;
var yPosition = e.clientY;
}
< script >
var myimgobj = document.images["jsbutton"];
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.beginPath();
ctx.arc(300, 400, 40, 0, 6 * Math.PI);
ctx.stroke();
ctx.fillStyle = '#AFEEEE';
ctx.fill();
ctx.stroke();
ctx.strokeStyle = "#F0E68C";
ctx.lineWidth = 5;
ctx.stroke();
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.beginPath();
ctx.fillRect(100, 100, 400, 40);
ctx.stroke();
ctx.fillStyle = '#AFEEEE';
ctx.fill();
ctx.stroke();
ctx.strokeStyle = "#F0E68C";
ctx.lineWidth = 5;
ctx.stroke();
< /script>
< p > This example uses the HTML DOM to assign an "onclick"
event to a p element. < /p>
< p id = "demo" > SEND. < /p>
< script >
document.getElementById("demo").onclick = function() {
myFunction()
};
function myFunction() {
document.getElementById("demo").innerHTML = "SENT TO SERVER!";
}
< /script>
< /body> < /html>
{{CanvasSidebar}}Added in HTML5, the HTML {{HTMLElement("canvas")}} element can be used to draw graphics via scripting in JavaScript. For example, it can be used to draw graphs, make photo compositions, create animations, or even do real-time video processing or rendering.
Mozilla applications gained support for <canvas>
starting with Gecko 1.8 (i.e. Firefox 1.5). The element was originally introduced by Apple for the OS X Dashboard and Safari. Internet Explorer supports <canvas>
from version 9 onwards; for earlier versions of IE, a page can effectively add support for <canvas>
by including a script from Google's Explorer Canvas project. Google Chrome and Opera 9 also support <canvas>
.
The <canvas>
element is also used by WebGL to do hardware-accelerated 3D graphics on web pages.
Example
This is just a simple code snippet which uses the {{domxref("CanvasRenderingContext2D.fillRect()")}} method.
HTML
<canvas id="canvas"></canvas>
JavaScript
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); ctx.fillStyle = "green"; ctx.fillRect(10, 10, 100, 100);
Edit the code below and see your changes update live in the canvas:
{{ EmbedLiveSample('Playable_code', 700, 360) }}
Reference
- {{domxref("HTMLCanvasElement")}}
- {{domxref("CanvasRenderingContext2D")}}
- {{domxref("CanvasGradient")}}
- {{domxref("CanvasPattern")}}
- {{domxref("ImageData")}}
- {{domxref("TextMetrics")}}
- {{domxref("Path2D")}} {{experimental_inline}}
The interfaces related to the WebGLRenderingContext
are referenced under WebGL.
Guides and tutorials
- Canvas tutorial
- A comprehensive tutorial covering both the basic usage of
<canvas>
and its advanced features. - Code snippets: Canvas
- Some extension developer-oriented code snippets involving
<canvas>
. - Demo: A basic ray-caster
- A demo of ray-tracing animation using canvas.
- Drawing DOM objects into a canvas
- How to draw DOM content, such as HTML elements, into a canvas.
- Manipulating video using canvas
- Combining {{HTMLElement("video")}} and {{HTMLElement("canvas")}} to manipulate video data in real time.
Resources
Generic
Libraries
- Fabric.js is an open-source canvas library with SVG parsing capabilities.
- Kinetic.js is an open-source canvas library focused on interactivity for desktop and mobile applications.
- Paper.js is an open source vector graphics scripting framework that runs on top of the HTML5 Canvas.
- libCanvas is powerful and lightweight canvas framework.
- Processing.js is a port of the Processing visualization language.
- PlayCanvas is an open source game engine.
- Pixi.js is an open source game engine.
- PlotKit is a charting and graphing library.
- Rekapi is an animation key-framing API for Canvas.
- PhiloGL is a WebGL framework for data visualization, creative coding and game development.
- JavaScript InfoVis Toolkit creates interactive 2D Canvas data visualizations for the Web.
Specifications
Specification | Status | Comment |
---|---|---|
{{SpecName('HTML WHATWG', "the-canvas-element.html", "Canvas")}} | {{Spec2('HTML WHATWG')}} |