Web storage started as part of the HTML5 spec for storing key-value pair data in web clients. It now has its own spec. There are other plans for storing databases that are structured and can be queried using SQL which are handled in a separate spec . Seeing the need for storing more key-value pair [...]
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 [...]
This post is about making drag and drop work on a canvas in Internet Explorer versions 6, 7 and 8 . The details of how to drag and drop on the canvas can be found in this previous post. How to Drag and Drop on an HTML5 Canvas To modify our canvas in order to [...]
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 [...]
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 [...]
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 C++ long ago by creating an elevator simulation game (thanks Tom Swan). It’s fun and it is the closest you can come to [...]
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 [...]
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 [...]
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 [...]
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 [...]