Graphing Data in the HTML5 Canvas Element Part IV Simple Pie Charts

In this post we will create a simple pie chart that is easy to feed data to. This example is coded for readability and not for optimized operation. All you need is a text editor like notepad and an HTML5 friendly browser (I’m using Firefox 3.6). <!doctype html> <html> <head> <meta charset=”UTF-8″ /> <title>Canvas Test</title> […]

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Using Multiple HTML5 Canvases as Layers

DEMO Here’s our finished canvas with full source code. The reasons why you would want to layer multiple canvases on top of each other are many but they all have a common root. There is a requirement in the W3C definition of the 2d context… There is only one CanvasRenderingContext2D object per canvas, so calling […]

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Slicing Spritemaps and Parallax Scrolling on the HTML5 Canvas

In this example we will look at slicing images with the drawImage() method of a 2d canvas context. We’ll use two images that are larger than the canvas to create a parallax scrolling effect that is common in 2d games and also another image as a spritemap consisting of three sprites to show how to […]

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Graphing Data in the HTML5 Canvas Element Part III

This is post 3 of a multipart series of posts. All of the code to try this example for yourself is included here but much of it is explained in the previous posts. The first and second parts can be found here. Graphing Data in the HTML5 Canvas Element Part I Graphing Data in the […]

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Make a Maze Game on an HTML5 Canvas

UPDATE: 8-28-2013 This post is expanded on in the new post ‘Build Responsive Games For Mobile Phones, Tablets and Computers with HTML5 Canvas’ One of the best ways to learn how to program in any language is to make a game and then change the code to create different variations on the game. I learned […]

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Understanding save() and restore() for the Canvas Context

At first, I had a hard time grasping the purpose and use of the save() and restore() methods of the canvas’ 2d context. It’s really very simple and here are some examples that can help you understand it better. Let’s look at an official definition of save() and restore() Each context maintains a stack of […]

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How to Drag and Drop on an HTML5 Canvas

We explored using keyboard input to move a shape on an HTML5 canvas here http://html5.litten.com/moving-shapes-on-the-html5-canvas-with-the-keyboard/. Now we’ll take a look at using input from the mouse. With a few simple calculations, you can drag and drop shapes on the canvas with your mouse. UPDATE: I’ve added a companion post for IE compatibility. IE Compatible Canvas […]

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Graphing Data in the HTML5 Canvas Element Part II

This is post 2 of a multipart series of posts. The first part can be found here… http://html5.litten.com/graphing-data-in-the-html5-canvas-element-part-i/ In this post we will do the following. Move the graph to the center of a larger canvas Add a meaningful background Add labels to the x and y axes This will allow us to go from […]

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Moving Shapes on the HTML5 Canvas With the Keyboard

In order to make games using an HTML5 canvas element, you need to be able to detect user input. This post shows how to capture keystrokes on the keyboard and use them to manipulate shapes on the canvas. This example is coded for readability and not for optimized operation. All you need is a text […]

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