A Glance Into The Remarkable HTML5 Canvas And Its Features

Rick Brown

Like a canvas is a quite significant object for a painter, similarly the HTML5 Canvas offers a great freedom to HTML5 web developers so that they can seamlessly transform their creative imagination with innovative graphics and animations in reality.

Yes! Today, the robust web technology HTML5 has made the web browsers a powerful platform that can be even used for flawlessly creating desired animations and graphics. Many web developers have already started reaping its benefits and developed beautiful applications and web designs featuring astonishing graphical effects created via the HTML5 Canvas.

For the folks who are interested in deploying this incredibly useful technology, I have included a small and precise guide to make it easier to get started with HTML5 Canvas. It will include the basic structure of the canvas elements, and a few examples to showcase how you can draw some shapes or path by implementing HTML5 Canvas.

Let's begin.

HTML5 canvas is a brilliant web technology that has enabled developers to design straightaway into the modern web browsers, without using any plugin. It can be done with a flair and trendy designs can be created, once your basics will be clear.

Canvas Element – A Foreword

The Canvas element is just a simple HTML tag that has a definite height and width. This fancy browser feature is easy to use. By implementing the canvas element, a transparent canvas will be inserted on your page. While including defined dimensions, it also includes the fallback content that will be showcased on the screen in case the canvas is not compatible with your browser. However, it is interesting to note that most of the modern browsers, including Internet Explorer, Chrome, Safari, Android, iOS, Mozilla Firefox, and more, support it.

<canvas width="450" height="450">
<!-- add detail that you want to show-->
</canvas>

It allows one to conveniently draw graphics through scripting and offers myriads of methods by using which you can draw paths, boxes, texts or include requisite images. The canvas will be displayed in a rectangle shape in a web application and you can then draw desired shapes via JavaScript.

The HTML5 Canvas element comes complete with a canvas API that, when coupled with JavaScript facilitates an easy access to certain areas of canvas through some drawing functions. It, thus, allows one to create dynamic graphics with ease.

Dimensions of Canvas: The two attributes, namely the height and width of the canvas are required to be set explicitly while defining the dimensions of the canvas. You may choose to use the CSS to proficiently scale up or down the size of your canvas. However, it will also have an odd effect.

2D Rendering Context – A Foreword

After the canvas element, the second essential part of the HTML5 canvas is the 2D rendering context. While the canvas element allows you to create a transparent canvas on the screen, 2D rendering context allows one to create beautiful graphics and effects. Thus, it is clear that drawing is done in the 2D rendering context that is accessed via the canvas element through the JavaScript API.

The coordinate system used here is quite similar to the coordinate system of the other 2D programming languages. It implements the standard Cartesian coordinate system, where the origin (0,0) is at the top left. Each unit on the coordinate system corresponds to a pixel on the screen.

Implementing HTML5 Canvas

In order to start drawing with the HTML5 canvas, you will need a code editor, and a compatible browser.

Code Snippet of HTML:
<canvas id="featureCanvas" style="background: #333;" width="450" height="250">
<!-- add details that you want to display -->
</canvas>

Code Snippet of JavaScript to access the rendering context:
var elementID = document.getElementById('featureCanvas');
drawElement = elementID.getContext('2d');
// define example...

On executing the aforementioned HTML code appropriately, a canvas element with width 450 pixels and height 250 pixels will be created. The id attribute is assigned to the canvas, you can use it and implement CSS to make your transparent canvas visible in a thin frame.

In the JavaScript code, the elementID variable is created to catch the canvas element, and the drawElement variable is created to refer to the 2D rendering context via the getContext() function.

Let's have a look at a few examples.

Example 1: To draw a rectangle
Add the below mentioned lines of code to create a rectangle.

<script>
var elementID = document.getElementById("featureCanvas");
var drawElement = elementID.getContext("2d");
drawElement.fillStyle = "#CCC";
drawElement.fillRect(20,20,410,210);
drawElement.fillStyle = "#333";
drawElement.font = "22px Arial";
drawElement.fillText("Draw a rectangle path",110,130);
</script>

OUTPUT

Example 2: To draw a triangle path

For creating a triangle path, a list of API methods are called to create a triangle path.

<script>
var elementID = document.getElementById("featureCanvas");
var drawElement = elementID.getContext("2d");
drawElement.beginPath();
drawElement.moveTo(20, 20);
drawElement.lineTo(20, 230);
drawElement.lineTo(220, 230);
drawElement.closePath();
drawElement.fillStyle = "#CCC";
drawElement.fill();
drawElement.font = "22px Arial";
drawElement.fillText("Draw a triangle path",140,70);
</script>

OUTPUT

Applications that can be embellished via HTML5 Canvas

You can create a variety of captivating and feature-rich applications by implementing the HTML5 Canvas. Here are a few of them.

Games – You can create fabulous 2D and 3D games with the powerful HTML5 canvas.
Advertising – If your business needs an application to promote your products and services with a mind-blowing advertisement, HTML5 Canvas can amazingly cater to your needs. It allows one to create attractive and enticing ads without implementing the Flash.

Education – For rendering an ultimate learning experience, you can rely upon the HTML5 canvas. You can efficiently embed requisite videos, images, text, etc. in a desired format.

These are a few examples of applications, where HTML5 canvas can be implemented. However, I believe that it can be used in almost any kind of application.

Wrapping Up

This is a precise guide elucidating the essential terms related to the HTML5 canvas. The included examples further describe an ideal way to implement the technology and design stunning graphics on the web browser. I hope this will make it easier for you to get started with designing apps via the HTML5 canvas.

Author Signature: Rick Brown is an app developer working with Mobiers Ltd, which is the leading mobile application development company. In case, you are willing to dig-out more information about the related services, get in touch with him.








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