HTML5 element <canvas> gives you an easy and powerful way to
draw graphics using JavaScript. It can be used to draw graphs, make
photo compositions or do simple (and not so simple) animations.
Here is a simple <canvas> element which has only two specific attributes
width and
height plus all the core HTML5 attributes like id, name and class etc.
<canvas id="mycanvas" width="100" height="100"></canvas>
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You can easily find that <canvas> element in the DOM using
getElementById() method as follows:
var canvas = document.getElementById("mycanvas");
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Let us see a simple example on using <canvas> element in HTML5 document.
<!DOCTYPE HTML>
<html>
<head>
<style>
#mycanvas{
border:1px solid red;
}
</style>
</head>
<body>
<canvas id="mycanvas" width="100" height="100"></canvas>
</body>
</html>
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To learn above concept -
Do Online Practice using latest version of either Safari or Opera.
The Rendering Context:
The <canvas> is initially blank, and to display something, a
script first needs to access the rendering context and draw on it.
The canvas element has a DOM method called
getContext, used to obtain the rendering context and its drawing functions. This function takes one parameter, the type of context
2d.
Following is the code to get required context along with a check if your browser supports <canvas> element:
var canvas = document.getElementById("mycanvas");
if (canvas.getContext){
var ctx = canvas.getContext('2d');
// drawing code here
} else {
// canvas-unsupported code here
}
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Browser Support
The latest versions of Firefox, Safari, Chrome and Opera all support for HTML5 Canvas but IE8 does not support canvas natively.
You can use
ExplorerCanvas to have canvas support through Internet Explorer. You just need to include this javascript as follows:
<!--[if IE]><script src="excanvas.js"></script><![endif]-->
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HTML5 Canvas Examples:
This tutorial covers following examples related to HTML5 <canvas> element.
| Examples | Description |
|---|
| Drawing Rectangles | Learn how to draw rectangle using HTML5 <canvas> element |
| Drawing Paths | Learn how to make shapes using paths in HTML5 <canvas> element |
| Drawing Lines | Learn how to draw lines using HTML5 <canvas> element |
| Drawing Bezier | Learn how to draw bezier curve using HTML5 <canvas> element |
| Drawing Quadratic | Learn how to draw quadratic curve using HTML5 <canvas> element |
| Using Images | Learn how to use images with HTML5 <canvas> element |
| Create Gradients | Learn how to create gradients using HTML5 <canvas> element |
| Styles and Colors | Learn how to apply styles and colors using HTML5 <canvas> element |
| Text and Fonts | Learn how to draw amazing text using different fonts and their size. |
| Pattern and Shadow | Learn how to draw different patterns and drop shadows. |
| Canvas States | Learn how to save and restore canvas states while doing complex drawings on a canvas. |
| Canvas Translation | This method is used to move the canvas and its origin to a different point in the grid. |
| Canvas Rotation | This method is used to rotate the canvas around the current origin. |
| Canvas Scaling | This method is used to increase or decrease the units in a canvas grid. |
| Canvas Transform | These methods allow modifications directly to the transformation matrix. |
| Canvas Composition | This method is used to mask off certain areas or clear sections from the canvas. |
| Canvas Animation | Learn how to create basic animation using HTML5 canvas and Javascript. |
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