Exhibit #2: Getting Info about WebGL Context

Parameters

Name	Value
UNMASKED_VENDOR_WEBGL	Google Inc. (Google)
UNMASKED_RENDERER_WEBGL	ANGLE (Google, Vulkan 1.3.0 (SwiftShader Device (LLVM 10.0.0) (0x0000C0DE)), SwiftShader driver)
MAX_TEXTURE_SIZE	8192
MAX_CUBE_MAP_TEXTURE_SIZE	16384
MAX_RENDERBUFFER_SIZE	8192
MAX_VERTEX_TEXTURE_IMAGE_UNITS	32
MAX_TEXTURE_IMAGE_UNITS	32
MAX_COMBINED_TEXTURE_IMAGE_UNITS	64
MAX_VERTEX_ATTRIBS	16
MAX_VERTEX_UNIFORM_VECTORS	4096
MAX_FRAGMENT_UNIFORM_VECTORS	4096
MAX_VARYING_VECTORS	31

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().