Exhibit #2: Getting Info about WebGL Context

Parameters

Extensions

What We Did

• The WebGL context has a number of constant fields. You can access them in two ways.
  • gl.POINTS
  • gl["POINTS"]
  Let's try this out in the console.
• Some of these constants are names for the parameters of the WebGL context. Some parameters indicate the limit of what the context can do.
  • How large can a texture be?
  • How many textures can you use at the same time?
  • How many uniforms for varying variables you can use in your program?
  • etc.
• To get the values of these parameters, use gl.getParameter( ... intert-parameter-constant ... ). For example,
  • gl.getParameter(gl.MAX_TEXTURE_SIZE)
  • gl.getParameter(gl["MAX_TEXTURE_SIZE"])
• The WebGL implementation on your terminal might support extensions. An extension is a set of functionality that is not part of the official WebGL specification. It is disabled by default. You have to turn it on to use it.
• To get the names of supported extensions, use gl.getSupportedExtensions().