GLContext

Creates a WebGLRenderingContext and augments it with extra methods and properties. All methods and properties of WebGLRenderingContext can be directly accessed from this class.

Constructor

new L3D.GLContext(options)

Parameters

options

Object

supported options:

Properties

`canvas`	Canvas	The canvas to use.
`width`	Number	The width of the canvas to be created.
`height`	Number	The height of the canvas to be created.
`container`	Element \| String	The containing element for the created canvas.
`version`	Number	The version of WebGL to use, either 1 or 2. 0 or undefined will use the greatest available version.

Properties

currentShader GLShader

currently bound shader.

extensions Object

Stores common used extensions so they can be checked if they are supported.

height number

The canvas height, in pixels.

id number

Unique ID for this GLContext.

maxAnisotropy number

maxCombinedTextures number

maxCubeMapSize number

maxFragmentUniformVectors number

maxTextureSize number

maxTextureUnits number

maxVaryingVectors number

maxVertexAttribs number

maxVertexTextures number

maxVertexUniformVectors number

maxViewport Int32Array

onDestroy Signal

Emitted when the context is destroyed so objects can free their resources.

onDrawFrame Signal

Emitted so objects can draw into the current frame.

onLoseContext Signal

Emitted when the context has been lost so objects can free their resources and prepare for a new context being created.

onUpdate Signal

Emitted before rendering so listeners can do any updating for the next frame.

resourceManager GLResourceManager

Manages a cache of GL objects.

state GLState

The GLState object managing pushing and popping of state values.

vendor String

version String

viewportData Float32Array

The current viewport dimensions

webgl2 bool

True if this context is WebGL 2.

webglVersion number

The version of WebGL used by this context, either 2 or 1.

width number

The canvas width, in pixels.

Methods

static cloneCanvas(canvas) → Canvas

Clone a canvas element.

Parameters

canvas

Canvas

The canvas to clone.

Returns

Canvas

The created canvas.

static createCanvas(width, height) → Canvas

Create a canvas element.

Parameters

`width`	number	The width of the created canvas.
`height`	number	The height of the created canvas.

Returns

Canvas

The created canvas.

animate()

Launch animation loop (calls gl.onUpdate and gl.onDrawFrame every frame) example: gl.onDrawFrame.addListener(function(){ ... }) or gl.onUpdate.addListener(function(dt) { ... })

destroy()

Destroy this WebGL context and removes the Canvas from the DOM.

drawFrame()

Request all objects listening to onDrawFrame to draw.

exitPointerLock()

Release the pointer lock from the canvas.

fullscreen()

Launches the canvas in fullscreen mode

getAspectRatio() → number

Get the aspect ratio of the canvas.

Returns

number

The aspect ratio, width / height.

getUniformFunction(data) → function

Get the setter function to use for a uniform given a WebGLActiveInfo.

Parameters

data

WebGLActiveInfo

Info about the active uniform.

Returns

function

The uniform setter function, bound to the GL context, such as uniform1f.

getViewport(v)

Get the dimensions of the viewport

Parameters

v

Array.<number>

Optional storage for the results.

requestFrame()

Request a frame to be drawn. This is done asynchrounously, and multiple calls to requestFrame called before the frame is drawn will be consolidated.

requestPointerLock()

Request pointer lock for the canvas. This needs to be done from a user event, such as mousedown or touchdown.

reset()

Reset the the initial gl state

setViewport(v, flipY)

Set the dimensions of the viewport.

Parameters

`v`	array.<number>	Dimensions of the viewport
`flipY`	bool	If true, flip the y coordinate of the viewport so the origin is the bottom-left corner of the viewport.

snapshot(startx, starty, areax, areay, skipReverse) → Canvas

Returns a canvas with a snapshot of an area. This is safer than using the canvas itself due to internals of WebGL.

Parameters

`startx`	number	Viewport x coordinate
`starty`	number	Viewport y coordinate, from bottom of the canvas.
`areax`	number	Viewport area width.
`areay`	number	Viewport area height.
`skipReverse`	bool	If false, the canvas image will be flipped vertically.

Returns

Canvas

canvas

updateResolution()

Call this when the size of the canvas has changed to update the resolution of the canvas to match.

viewport(a, b, c, d)

Set the dimensions of the viewport.

Parameters

`a`	number
`b`	number
`c`	number
`d`	number