This tutorial describes how to use the <canvas> element to draw WebGL graphics, starting with the basics. The examples provided should give you some clear ideas what you can do with WebGL and will provide code snippets that may get you started in building your own content.
The content inside the <canvas> ... </canvas> tags can be used as a fallback for browsers which don't support canvas rendering. It's also very useful for assistive technology users (like screen readers) which can read and interpret the sub DOM in it. A good example at html5accessibility.com demonstrates how this can be done:
If you would like to use the WebSocket API, it is useful if you have a server. In this article I will show you how to write one in C#. You can do it in any server-side language, but to keep things simple and more understandable, I chose Microsoft's language.
At first sight a <canvas> looks like the <img> element, with the only clear difference being that it doesn't have the src and alt attributes. Indeed, the <canvas> element has only two attributes, width and height. These are both optional and can also be set using DOMproperties. When no width and height attributes are specified, the canvas will initially be 300 pixels wide and 150 pixels high. The element can be sized arbitrarily by CSS, but during rendering the image is scaled to fit its layout size: if the CSS sizing doesn't respect the ratio of the initial canvas, it will appear distorted.
The RTCDataChannel interface is a feature of the WebRTC API which lets you open a channel between two peers over which you may send and receive arbitrary data. The API is intentionally similar to the WebSocket API, so that the same programming model can be used for each.