Book Image

HTML5 Canvas Cookbook

By : Eric Rowell
Book Image

HTML5 Canvas Cookbook

By: Eric Rowell

Overview of this book

The HTML5 canvas is revolutionizing graphics and visualizations on the Web. Powered by JavaScript, the HTML5 Canvas API enables web developers to create visualizations and animations right in the browser without Flash. Although the HTML5 Canvas is quickly becoming the standard for online graphics and interactivity, many developers fail to exercise all of the features that this powerful technology has to offer.The HTML5 Canvas Cookbook begins by covering the basics of the HTML5 Canvas API and then progresses by providing advanced techniques for handling features not directly supported by the API such as animation and canvas interactivity. It winds up by providing detailed templates for a few of the most common HTML5 canvas applications—data visualization, game development, and 3D modeling. It will acquaint you with interesting topics such as fractals, animation, physics, color models, and matrix mathematics. By the end of this book, you will have a solid understanding of the HTML5 Canvas API and a toolbox of techniques for creating any type of HTML5 Canvas application, limited only by the extent of your imagination.
Table of Contents (19 chapters)
HTML5 Canvas Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Canvas Security
Index

Creating a linear motion


In this recipe, we'll try out our Animation class by creating a simple linear motion animation by moving a box from the left of the canvas to the right of the canvas:

How to do it...

Follow these steps to move a box from one side of the canvas to the other:

  1. Link to the Animation class:

    <head>
        <script src="animation.js">
        </script>
  2. Instantiate an Animation object and get the canvas context:

        <script>
            window.onload = function(){
                var anim = new Animation("myCanvas");
                var canvas = anim.getCanvas();
                var context = anim.getContext();
  3. Define the box's linear speed and create a box object that contains the box's position and size:

                var linearSpeed = 100; // pixels / second
                var box = {
                    x: 0,
                    y: canvas.height / 2 - 25,
                    width: 100,
                    height: 50
                };
  4. Set the stage() function, which updates the box's position, clears...