StageGL Class

Extends Stage

Defined in: StageGL:56

Module: EaselJS

A StageGL instance is the root level Container for an WebGL-optimized display list, which is used in place of the usual Stage. This class should behave identically to a Stage except for WebGL-specific functionality.

Each time the tick method is called, the display list is rendered to the target <canvas/> instance, ignoring non-WebGL-compatible display objects. On devices and browsers that don't support WebGL, content will automatically be rendered to canvas 2D context instead.

Limitations

Shape, Shadow, and Text are not rendered when added to the display list.
To display something StageGL cannot render, cache the object. Caches can be rendered regardless of source.
Images are wrapped as a webGL "Texture". Each graphics card has a limit to its concurrent Textures, too many Textures will noticeably slow performance.
Each cache counts as an individual Texture. As such SpriteSheet and SpriteSheetBuilder are recommended practices to help keep texture counts low.
To use any image node (DOM Image/Canvas Element) between multiple StageGL instances it must be a clone, otherwise the GPU texture loading and tracking will get confused.
to avoid an up/down scaled render you must call updateViewport if you resize your canvas after making a StageGL instance, this will properly size the WebGL context stored in memory.
Best performance in demanding scenarios will come from manual management of texture memory, but it is handled automatically by default. See releaseTexture for details.

Example

This example creates a StageGL instance, adds a child to it, then uses the EaselJS Ticker to update the child and redraw the stage.

 var stage = new createjs.StageGL("canvasElementId");

 var image = new createjs.Bitmap("imagePath.png");
 stage.addChild(image);

 createjs.Ticker.on("tick", handleTick);

 function handleTick(event) {
     image.x += 10;
     stage.update();
 }

Notes

StageGL is not currently included in the minified version of EaselJS.
SpriteContainer (the previous approach to WebGL with EaselJS) has been deprecated.
Earlier versions of WebGL support in EaselJS (SpriteStage and SpriteContainer) had hard limitations on images per container, which have been solved.

Constructor

`StageGL`

(

canvas
options

)

Defined in StageGL:56

Parameters:

canvas HTMLCanvasElement | String | Object

A canvas object that StageGL will render to, or the string id of a canvas object in the current DOM.
options Object

All the option parameters in a reference object, some are not supported by some browsers.
- [preserveBuffer=false] Boolean optional
  
  If true, the canvas is NOT auto-cleared by WebGL (the spec discourages setting this to true). This is useful if you want persistent draw effects.
- [antialias=false] Boolean optional
  
  Specifies whether or not the browser's WebGL implementation should try to perform anti-aliasing. This will also enable linear pixel sampling on power-of-two textures (smoother images).
- [transparent=false] Boolean optional
  
  If true, the canvas is transparent. This is very expensive, and should be used with caution.
- [premultiply=false] Boolean optional
  
  Alters color handling. If true, this assumes the shader must account for pre-multiplied alpha. This can help avoid visual halo effects with some assets, but may also cause problems with other assets.
- [autoPurge=1200] Integer optional
  
  How often the system should automatically dump unused textures with purgeTextures(autoPurge) every autoPurge/2 draws. See purgeTextures for more information.

Index
Methods
Properties
Events

Item Index

Methods

`_appendToBatchGroup`

(

container
gl
concatMtx
concatAlpha
ignoreCache

)

protected

Defined in _appendToBatchGroup:2194

Add all the contents of a container to the pending buffers, called recursively on each container. This may trigger a draw if a buffer runs out of space. This is the main workforce of the render loop.

Parameters:

container Container

The Container that contains everything to be drawn.
gl WebGLRenderingContext

The canvas WebGL context object to draw into.
concatMtx Matrix2D

The effective (concatenated) transformation matrix when beginning this container
concatAlpha Number

The effective (concatenated) alpha when beginning this container
ignoreCache Boolean

Don't use an element's cache during this draw

`_applyShadow`

(

ctx
shadow

)

protected

Inherited from DisplayObject: _applyShadow:1273

Parameters:

ctx CanvasRenderingContext2D
shadow Shadow

`_backupBatchTextures`

(

restore
[target=this._backupTextures]

)

protected

Defined in _backupBatchTextures:1975

Store or restore current batch textures into a backup array

Parameters:

restore Boolean

Perform a restore instead of a store.
[target=this._backupTextures] Array optional

Where to perform the backup, defaults to internal backup.

`_batchDraw`

(

gl
sceneGraph
ignoreCache

)

protected

Defined in _batchDraw:2003

Begin the drawing process for a regular render.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.
sceneGraph Stage | | Container

Container object with all that needs to rendered, preferably a Stage.
ignoreCache Boolean

`_cacheDraw`

(

target
filters
manager

)

protected

Defined in _cacheDraw:2028

Perform the drawing process to fill a specific cache texture, including applying filters.

Parameters:

target DisplayObject

The object we're drawing into the cache. For example, used for drawing the cache (to prevent it from simply drawing an existing cache back into itself).
filters Array

The filters we're drawing into cache.
manager BitmapCache

The BitmapCache instance looking after the cache

`_cloneProps`

(

)

DisplayObject protected

Inherited from DisplayObject: _cloneProps:1240

Parameters:

o DisplayObject

The DisplayObject instance which will have properties from the current DisplayObject instance copied into.

Returns:

DisplayObject:

`_createBuffers`

(

gl

)

protected

Defined in _createBuffers:1665

Sets up the necessary vertex property buffers, including position and U/V.

Parameters:

gl WebGLRenderingContext

`_createShader`

(

gl
type
str

)

WebGLShader protected

Defined in _createShader:1630

Creates a shader from the specified string replacing templates. Template items are defined via {{ key }}`.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.
type Number

The type of shader to create. gl.VERTEX_SHADER | gl.FRAGMENT_SHADER
str String

The definition for the shader.

Returns:

WebGLShader:

`_dispatchEvent`

(

eventObj
eventPhase

)

protected

Inherited from EventDispatcher: _dispatchEvent:380

Parameters:

eventObj Object | Event
eventPhase Object

`_dispatchMouseEvent`

(

target
type
bubbles
pointerId
o
[nativeEvent]
[relatedTarget]

)

protected

Inherited from Stage: _dispatchMouseEvent:838

Parameters:

target DisplayObject
type String
bubbles Boolean
pointerId Number
o Object
[nativeEvent] MouseEvent optional
[relatedTarget] DisplayObject optional

`_drawBuffers`

(

gl
flipY

)

protected

Defined in _drawBuffers:2425

Draws a card that covers the entire render surface. Mainly used for filters.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.
flipY Boolean

Covers are used for things like RenderTextures and because of 3D vs Canvas space this can end up meaning the y space sometimes requires flipping in the render.

`_drawBuffers`

(

gl

)

protected

Defined in _drawBuffers:2376

Draws all the currently defined cards in the buffer to the render surface.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.

`_drawFilters`

(

target
filters
manager

)

Defined in _drawFilters:2100

Sub portion of _cacheDraw, split off for readability. Do not call independently.

Parameters:

target DisplayObject

The object we're drawing with a filter.
filters Array

The filters we're drawing into cache.
manager BitmapCache

The BitmapCache instance looking after the cache

`_fetchShaderProgram`

(

gl
[shaderName="regular"]
[customVTX]
[customFRAG]
[shaderParamSetup]

)

WebGLProgram protected

Defined in _fetchShaderProgram:1514

Create the completed Shader Program from the vertex and fragment shaders. Allows building of custom shaders for filters. Once compiled, shaders are saved so. If the Shader code requires dynamic alterations re-run this function to generate a new shader.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.
[shaderName="regular"] String optional

Working values: "regular", "override", and "filter". Which type of shader to build. Filter and override both accept the custom params. Regular and override have all features. Filter is a special case reduced feature shader meant to be over-ridden.
[customVTX] String optional

Extra vertex shader information to replace a regular draw, see StageGL/COVER_VERTEX_BODY for default and Filter for examples.
[customFRAG] String optional

Extra fragment shader information to replace a regular draw, see StageGL/COVER_FRAGMENT_BODY for default and Filter for examples.
[shaderParamSetup] Function optional

Function to run so custom shader parameters can get applied for the render.

Returns:

WebGLProgram:

The compiled and linked shader

`_fetchWebGLContext`

(

canvas
options

)

WebGLRenderingContext protected

Defined in _fetchWebGLContext:1485

Sets up and returns the WebGL context for the canvas. May return undefined in error scenarios. These can include situations where the canvas element already has a context, 2D or GL.

Parameters:

canvas Canvas

The DOM canvas element to attach to
options Object

The options to be handed into the WebGL object, see WebGL spec

Returns:

WebGLRenderingContext:

The WebGL context, may return undefined in error scenarios

`_getBounds`

(

matrix
ignoreTransform

)

Rectangle protected

Inherited from DisplayObject but overwritten in _getBounds:682

Parameters:

matrix Matrix2D
ignoreTransform Boolean

If true, does not apply this object's transform.

Returns:

Rectangle:

`_getElementRect`

(

)

protected

Inherited from Stage: _getElementRect:571

Parameters:

e HTMLElement

`_getNumChildren`

() Number protected

Inherited from Container: _getNumChildren:96

Use the numChildren property instead.

Returns:

Number:

`_getObjectsUnderPoint`

(

x
y
arr
mouse
activeListener
currentDepth

)

DisplayObject protected

Inherited from Container: _getObjectsUnderPoint:597

Parameters:

x Number
y Number
arr Array
mouse Boolean

If true, it will respect mouse interaction properties like mouseEnabled, mouseChildren, and active listeners.
activeListener Boolean

If true, there is an active mouse event listener on a parent object.
currentDepth Number

Indicates the current depth of the search.

Returns:

DisplayObject:

`_getPointerData`

(

id

)

protected

Inherited from Stage: _getPointerData:599

Parameters:

id Number

`_getSafeTexture`

(

[w=1]
[h=1]

)

Defined in _getSafeTexture:1464

Returns a base texture that has no image or data loaded. Not intended for loading images. In some error cases, the texture creation will fail. This function differs from getBaseTexture in that the failed textures will be replaced with a safe to render "nothing" texture.

Parameters:

[w=1] Uint optional

The width of the texture in pixels, defaults to 1
[h=1] Uint optional

The height of the texture in pixels, defaults to 1

`_getStage`

() Stage protected

Inherited from DisplayObject: _getStage:677

Use the stage property instead.

Returns:

Stage:

`_handleDoubleClick`

(

e
owner

)

protected

Inherited from Stage: _handleDoubleClick:823

Parameters:

e MouseEvent
owner Stage

Indicates that the event has already been captured & handled by the indicated stage.

`_handleMouseDown`

(

)

protected

Inherited from Stage: _handleMouseDown:722

Parameters:

e MouseEvent

`_handleMouseMove`

(

)

protected

Inherited from Stage: _handleMouseMove:610

Parameters:

e MouseEvent

`_handleMouseUp`

(

)

protected

Inherited from Stage: _handleMouseUp:685

Parameters:

e MouseEvent

`_handlePointerDown`

(

id
e
pageX
pageY
owner

)

protected

Inherited from Stage: _handlePointerDown:731

Parameters:

id Number
e Event
pageX Number
pageY Number
owner Stage

Indicates that the event has already been captured & handled by the indicated stage.

`_handlePointerMove`

(

id
e
pageX
pageY
owner

)

protected

Inherited from Stage: _handlePointerMove:620

Parameters:

id Number
e Event
pageX Number
pageY Number
owner Stage

Indicates that the event has already been captured & handled by the indicated stage.

`_handlePointerUp`

(

id
e
clear
owner

)

protected

Inherited from Stage: _handlePointerUp:694

Parameters:

id Number
e Event
clear Boolean
owner Stage

Indicates that the event has already been captured & handled by the indicated stage.

`_initializeWebGL`

() WebGLRenderingContext protected

Defined in _initializeWebGL:893

Create and properly initialize the WebGL instance.

Returns:

WebGLRenderingContext:

`_initTextures`

() protected

Defined in _initTextures:1743

Do all the setup steps for textures in the system.

`_insertTextureInBatch`

(

gl
texture

)

protected

Defined in _insertTextureInBatch:1876

Adds the texture to a spot in the current batch, forcing a draw if no spots are free.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.
texture WebGLTexture

The texture to be inserted.

`_isMouseOpaque`

() Boolean protected

Inherited from DisplayObject: _isMouseOpaque:1364

Indicates whether the display object has any mouse event listeners or a cursor.

Returns:

Boolean:

`_killTextureObject`

(

texture

)

protected

Defined in _killTextureObject:1929

Remove and clean the texture, expects a texture and is inflexible. Mostly for internal use, recommended to call releaseTexture instead as it will call this with the correct texture object(s). Note: Testing shows this may not happen immediately, have to wait frames for WebGL to have actually adjust memory.

Parameters:

texture Texture

The texture to be cleaned out

`_loadTextureImage`

(

gl
image

)

WebGLTexture protected

Defined in _loadTextureImage:1772

Load a specific texture, accounting for potential delay, as it might not be preloaded.

Parameters:

gl WebGLRenderingContext
image Image | Canvas

Actual image to be loaded

Returns:

WebGLTexture:

The resulting Texture object

`_testHit`

(

ctx

)

Boolean protected

Inherited from DisplayObject: _testHit:1303

Parameters:

ctx CanvasRenderingContext2D

Returns:

Boolean:

`_testMask`

(

target
x
y

)

Boolean protected

Inherited from Container: _testMask:651

Parameters:

target DisplayObject
x Number
y Number

Returns:

Boolean:

Indicates whether the x/y is within the masked region.

`_testMouseOver`

(

clear
owner
eventTarget

)

protected

Inherited from Stage: _testMouseOver:754

Parameters:

clear Boolean

If true, clears the mouseover / rollover (ie. no target)
owner Stage

Indicates that the event has already been captured & handled by the indicated stage.
eventTarget Stage

The stage that the cursor is actively over.

`_tick`

(

evtObj

)

protected

Inherited from DisplayObject but overwritten in _tick:548

Parameters:

evtObj Object

An event object that will be dispatched to all tick listeners. This object is reused between dispatchers to reduce construction & GC costs.

`_transformBounds`

(

bounds
matrix
ignoreTransform

)

Rectangle protected

Inherited from DisplayObject: _transformBounds:1331

Parameters:

bounds Rectangle
matrix Matrix2D
ignoreTransform Boolean

Returns:

Rectangle:

`_updatePointerPosition`

(

id
e
pageX
pageY

)

protected

Inherited from Stage: _updatePointerPosition:648

Parameters:

id Number
e Event
pageX Number
pageY Number

`_updateState`

() protected

Inherited from DisplayObject: _updateState:1225

Called before the object gets drawn and is a chance to ensure the display state of the object is correct. Mostly used by MovieClip and BitmapText to correct their internal state and children prior to being drawn.

Is manually called via draw in a Stage but is automatically called when present in a StageGL instance.

`_updateTextureImageData`

(

gl
image

)

protected

Defined in _updateTextureImageData:1822

Necessary to upload the actual image data to the GPU. Without this the texture will be blank. Called automatically in most cases due to loading and caching APIs. Flagging an image source with _invalid = true will trigger this next time the image is rendered.

Parameters:

gl WebGLRenderingContext
image Image | Canvas

The image data to be uploaded

`addChild`

(

child

)

DisplayObject

Inherited from Container: addChild:178

Adds a child to the top of the display list.

Example

    container.addChild(bitmapInstance);

You can also add multiple children at once:

    container.addChild(bitmapInstance, shapeInstance, textInstance);

Parameters:

child DisplayObject

The display object to add.

Returns:

DisplayObject:

The child that was added, or the last child if multiple children were added.

`addChildAt`

(

child
index

)

DisplayObject

Inherited from Container: addChildAt:209

Adds a child to the display list at the specified index, bumping children at equal or greater indexes up one, and setting its parent to this Container.

Example

 addChildAt(child1, index);

You can also add multiple children, such as:

 addChildAt(child1, child2, ..., index);

The index must be between 0 and numChildren. For example, to add myShape under otherShape in the display list, you could use:

 container.addChildAt(myShape, container.getChildIndex(otherShape));

This would also bump otherShape's index up by one. Fails silently if the index is out of range.

Parameters:

child DisplayObject

The display object to add.
index Number

The index to add the child at.

Returns:

DisplayObject:

Returns the last child that was added, or the last child if multiple children were added.

`addEventListener`

(

type
listener
[useCapture]

)

Function | Object

Inherited from EventDispatcher: addEventListener:140

Adds the specified event listener. Note that adding multiple listeners to the same function will result in multiple callbacks getting fired.

Example

 displayObject.addEventListener("click", handleClick);
 function handleClick(event) {
    // Click happened.
 }

Parameters:

type String

The string type of the event.
listener Function | Object

An object with a handleEvent method, or a function that will be called when the event is dispatched.
[useCapture] Boolean optional

For events that bubble, indicates whether to listen for the event in the capture or bubbling/target phase.

Returns:

Function | Object:

Returns the listener for chaining or assignment.

`buildUVRects`

(

spritesheet
[target=-1]
[onlyTarget=false]

)

Object static

Defined in buildUVRects:461

Calculate the U/V co-ordinate based info for sprite frames. Instead of pixel count it uses a 0-1 space. Also includes the ability to get info back for a specific frame, or only calculate that one frame.

//generate UV rects for all entries
StageGL.buildUVRects( spriteSheetA );
//generate all, fetch the first
var firstFrame = StageGL.buildUVRects( spriteSheetB, 0 );
//generate the rect for just a single frame for performance's sake
var newFrame = StageGL.buildUVRects( dynamicSpriteSheet, newFrameIndex, true );

NOTE: This method is mainly for internal use, though it may be useful for advanced uses.

Parameters:

spritesheet SpriteSheet

The spritesheet to find the frames on
[target=-1] Int optional

The index of the frame to return
[onlyTarget=false] Boolean optional

Whether "target" is the only frame that gets calculated

Returns:

Object:

the target frame if supplied and present or a generic frame {t, l, b, r}

`cache`

(

x
y
width
height
[scale=1]
[options=undefined]

)

Inherited from DisplayObject: cache:803

Draws the display object into a new element, which is then used for subsequent draws. Intended for complex content that does not change frequently (ex. a Container with many children that do not move, or a complex vector Shape), this can provide for much faster rendering because the content does not need to be re-rendered each tick. The cached display object can be moved, rotated, faded, etc freely, however if its content changes, you must manually update the cache by calling updateCache() again. You must specify the cached area via the x, y, w, and h parameters. This defines the rectangle that will be rendered and cached using this display object's coordinates.

Example

For example if you defined a Shape that drew a circle at 0, 0 with a radius of 25:

 var shape = new createjs.Shape();
 shape.graphics.beginFill("#ff0000").drawCircle(0, 0, 25);
 shape.cache(-25, -25, 50, 50);

Note that filters need to be defined before the cache is applied or you will have to call updateCache after application. Check out the Filter class for more information. Some filters (ex. BlurFilter) may not work as expected in conjunction with the scale param.

Usually, the resulting cacheCanvas will have the dimensions width scale, height scale, however some filters (ex. BlurFilter) will add padding to the canvas dimensions.

In previous versions caching was handled on DisplayObject but has since been moved to BitmapCache. This allows for easier interaction and alternate cache methods like WebGL with StageGL. For more information on the options object, see the BitmapCache define.

Parameters:

x Number

The x coordinate origin for the cache region.
y Number

The y coordinate origin for the cache region.
width Number

The width of the cache region.
height Number

The height of the cache region.
[scale=1] Number optional

The scale at which the cache will be created. For example, if you cache a vector shape using myShape.cache(0,0,100,100,2) then the resulting cacheCanvas will be 200x200 px. This lets you scale and rotate cached elements with greater fidelity. Default is 1.
[options=undefined] Object optional

Specify additional parameters for the cache logic

`cacheDraw`

(

target
filters
manager

)

Boolean

Defined in cacheDraw:1002

Draws the target into the correct context, be it a canvas or Render Texture using WebGL.

NOTE: This method is mainly for internal use, though it may be useful for advanced uses.

Parameters:

target DisplayObject

The object we're drawing into cache. For example, used for drawing the cache (to prevent it from simply drawing an existing cache back into itself).
filters Array

The filters we're drawing into cache.
manager BitmapCache

The BitmapCache instance looking after the cache

Returns:

Boolean:

If the draw was handled by this function

`clear`

()

Inherited from Stage: clear:438

Clears the target canvas. Useful if autoClear is set to false.

`clone`

()

Inherited from DisplayObject but overwritten in clone:552

Stage instances cannot be cloned.

`cloneChildren`

(

)

protected

Inherited from Container: cloneChildren:563

Recursively clones all children of this container, and adds them to the target container.

Parameters:

o Container

The target container.

`contains`

(

child

)

Boolean

Inherited from Container: contains:435

Returns true if the specified display object either is this container or is a descendent (child, grandchild, etc) of this container.

Parameters:

child DisplayObject

The DisplayObject to be checked.

Returns:

Boolean:

true if the specified display object either is this container or is a descendent.

`dispatchEvent`

(

eventObj
[bubbles]
[cancelable]

)

Boolean

Inherited from EventDispatcher: dispatchEvent:285

Dispatches the specified event to all listeners.

Example

 // Use a string event
 this.dispatchEvent("complete");

 // Use an Event instance
 var event = new createjs.Event("progress");
 this.dispatchEvent(event);

Parameters:

eventObj Object | String | Event

An object with a "type" property, or a string type. While a generic object will work, it is recommended to use a CreateJS Event instance. If a string is used, dispatchEvent will construct an Event instance if necessary with the specified type. This latter approach can be used to avoid event object instantiation for non-bubbling events that may not have any listeners.
[bubbles] Boolean optional

Specifies the bubbles value when a string was passed to eventObj.
[cancelable] Boolean optional

Specifies the cancelable value when a string was passed to eventObj.

Returns:

Boolean:

Returns false if preventDefault() was called on a cancelable event, true otherwise.

`draw`

(

context
[ignoreCache=false]

)

Boolean

Inherited from DisplayObject but overwritten in draw:980

Draws the stage into the supplied context if possible. Many WebGL properties only exist on their context. As such you cannot share contexts among many StageGLs and each context requires a unique StageGL instance. Contexts that don't match the context managed by this StageGL will be treated as a 2D context.

NOTE: This method is mainly for internal use, though it may be useful for advanced uses.

Parameters:

context CanvasRenderingContext2D | WebGLRenderingContext

The context object to draw into.
[ignoreCache=false] Boolean optional

Indicates whether the draw operation should ignore any current cache. For example, used for drawing the cache (to prevent it from simply drawing an existing cache back into itself).

Returns:

Boolean:

If the draw was handled by this function

`enableDOMEvents`

(

[enable=true]

)

Inherited from Stage: enableDOMEvents:512

Enables or disables the event listeners that stage adds to DOM elements (window, document and canvas). It is good practice to disable events when disposing of a Stage instance, otherwise the stage will continue to receive events from the page.

When changing the canvas property you must disable the events on the old canvas, and enable events on the new canvas or mouse events will not work as expected. For example:

 myStage.enableDOMEvents(false);
 myStage.canvas = anotherCanvas;
 myStage.enableDOMEvents(true);

Parameters:

[enable=true] Boolean optional

Indicates whether to enable or disable the events. Default is true.

`enableMouseOver`

(

[frequency=20]

)

Inherited from Stage: enableMouseOver:481

Enables or disables (by passing a frequency of 0) mouse over (mouseover and mouseout) and roll over events (rollover and rollout) for this stage's display list. These events can be expensive to generate, so they are disabled by default. The frequency of the events can be controlled independently of mouse move events via the optional frequency parameter.

Example

 var stage = new createjs.Stage("canvasId");
 stage.enableMouseOver(10); // 10 updates per second

Parameters:

[frequency=20] Number optional

Optional param specifying the maximum number of times per second to broadcast mouse over/out events. Set to 0 to disable mouse over events completely. Maximum is 50. A lower frequency is less responsive, but uses less CPU.

`getBaseTexture`

(

[w=1]
[h=1]

)

Defined in getBaseTexture:1299

Returns a base texture that has no image or data loaded. Not intended for loading images. It may return null in some error cases, and trying to use a "null" texture can cause renders to fail.

Parameters:

[w=1] Uint optional

The width of the texture in pixels, defaults to 1
[h=1] Uint optional

The height of the texture in pixels, defaults to 1

`getBounds`

() Rectangle

Inherited from DisplayObject: getBounds:1100

Returns a rectangle representing this object's bounds in its local coordinate system (ie. with no transformation). Objects that have been cached will return the bounds of the cache.

Not all display objects can calculate their own bounds (ex. Shape). For these objects, you can use setBounds so that they are included when calculating Container bounds.

All	All display objects support setting bounds manually using setBounds(). Likewise, display objects that have been cached using cache() will return the bounds of their cache. Manual and cache bounds will override the automatic calculations listed below.
Bitmap	Returns the width and height of the Bitmap/sourceRect (if specified) or image, extending from (x=0,y=0).
Sprite	Returns the bounds of the current frame. May have non-zero x/y if a frame registration point was specified in the spritesheet data. See also getFrameBounds
Container	Returns the aggregate (combined) bounds of all children that return a non-null value from `getBounds()`.
Shape	Does not currently support automatic bounds calculations. Use `setBounds()` to manually define bounds.
Text	Returns approximate bounds. Horizontal values (x/width) are quite accurate, but vertical values (y/height) are not, especially when using textBaseline values other than "top".
BitmapText	Returns approximate bounds. Values will be more accurate if spritesheet frame registration points are close to (x=0,y=0).

Bounds can be expensive to calculate for some objects (ex. text, or containers with many children), and are recalculated each time you call getBounds(). You can prevent recalculation on static objects by setting the bounds explicitly:

var bounds = obj.getBounds();
obj.setBounds(bounds.x, bounds.y, bounds.width, bounds.height);
// getBounds will now use the set values, instead of recalculating

To reduce memory impact, the returned Rectangle instance may be reused internally; clone the instance or copy its values if you need to retain it.

var myBounds = obj.getBounds().clone();
// OR:
myRect.copy(obj.getBounds());

Returns:

Rectangle:

A Rectangle instance representing the bounds, or null if bounds are not available for this object.

`getCacheDataURL`

() String

Inherited from DisplayObject: getCacheDataURL:886

Returns a data URL for the cache, or null if this display object is not cached. Only generated if the cache has changed, otherwise returns last result.

Returns:

String:

The image data url for the cache.

`getChildAt`

(

index

)

DisplayObject

Inherited from Container: getChildAt:319

Returns the child at the specified index.

Example

 container.getChildAt(2);

Parameters:

index Number

The index of the child to return.

Returns:

DisplayObject:

The child at the specified index. Returns null if there is no child at the index.

`getChildByName`

(

name

)

DisplayObject

Inherited from Container: getChildByName:334

Returns the child with the specified name.

Parameters:

name String

The name of the child to return.

Returns:

DisplayObject:

The child with the specified name.

`getChildIndex`

(

child

)

Number

Inherited from Container: getChildIndex:368

Returns the index of the specified child in the display list, or -1 if it is not in the display list.

Example

 var index = container.getChildIndex(child);

Parameters:

child DisplayObject

The child to return the index of.

Returns:

Number:

The index of the specified child. -1 if the child is not found.

`getConcatenatedDisplayProps`

(

[props]

)

DisplayProps

Inherited from DisplayObject: getConcatenatedDisplayProps:1032

Generates a DisplayProps object representing the combined display properties of the object and all of its parent Containers up to the highest level ancestor (usually the Stage).

Parameters:

[props] DisplayProps optional

A DisplayProps object to populate with the calculated values. If null, a new DisplayProps object is returned.

Returns:

DisplayProps:

The combined display properties.

`getConcatenatedMatrix`

(

[matrix]

)

Matrix2D

Inherited from DisplayObject: getConcatenatedMatrix:1014

Generates a Matrix2D object representing the combined transform of the display object and all of its parent Containers up to the highest level ancestor (usually the Stage). This can be used to transform positions between coordinate spaces, such as with localToGlobal and globalToLocal.

Parameters:

[matrix] Matrix2D optional

A Matrix2D object to populate with the calculated values. If null, a new Matrix2D object is returned.

Returns:

Matrix2D:

The combined matrix.

`getFilterShader`

(

filter

)

WebGLProgram

Defined in getFilterShader:1264

Fetches the shader compiled and set up to work with the provided filter/object. The shader is compiled on first use and returned on subsequent calls.

Parameters:

filter Filter | Object

The object which will provide the information needed to construct the filter shader.

Returns:

WebGLProgram:

`getMatrix`

(

matrix

)

Matrix2D

Inherited from DisplayObject: getMatrix:1002

Returns a matrix based on this object's current transform.

Parameters:

matrix Matrix2D

Optional. A Matrix2D object to populate with the calculated values. If null, a new Matrix object is returned.

Returns:

Matrix2D:

A matrix representing this display object's transform.

`getNumChildren`

() deprecated

Inherited from Container: getNumChildren:106

Use the numChildren property instead.

`getObjectsUnderPoint`

(

x
y
[mode=0]

)

Array

Inherited from Container: getObjectsUnderPoint:465

Returns an array of all display objects under the specified coordinates that are in this container's display list. This routine ignores any display objects with mouseEnabled set to false. The array will be sorted in order of visual depth, with the top-most display object at index 0. This uses shape based hit detection, and can be an expensive operation to run, so it is best to use it carefully. For example, if testing for objects under the mouse, test on tick (instead of on stagemousemove), and only if the mouse's position has changed.

By default (mode=0) this method evaluates all display objects.
By setting the mode parameter to 1, the mouseEnabled and MouseChildren:property properties will be respected.
Setting the mode to 2 additionally excludes display objects that do not have active mouse event listeners or a DisplayObject:cursor:property property. That is, only objects that would normally intercept mouse interaction will be included. This can significantly improve performance in some cases by reducing the number of display objects that need to be tested.

This method accounts for both hitArea and mask.

Parameters:

x Number

The x position in the container to test.
y Number

The y position in the container to test.
[mode=0] Number optional

The mode to use to determine which display objects to include. 0-all, 1-respect mouseEnabled/mouseChildren, 2-only mouse opaque objects.

Returns:

Array:

An Array of DisplayObjects under the specified coordinates.

`getObjectUnderPoint`

(

x
y
mode

)

DisplayObject

Inherited from Container: getObjectUnderPoint:497

Similar to getObjectsUnderPoint, but returns only the top-most display object. This runs significantly faster than getObjectsUnderPoint(), but is still potentially an expensive operation. See getObjectsUnderPoint for more information.

Parameters:

x Number

The x position in the container to test.
y Number

The y position in the container to test.
mode Number

The mode to use to determine which display objects to include. 0-all, 1-respect mouseEnabled/mouseChildren, 2-only mouse opaque objects.

Returns:

DisplayObject:

The top-most display object under the specified coordinates.

`getRenderBufferTexture`

(

)

Texture

Defined in getRenderBufferTexture:1348

Returns a base texture (see getBaseTexture) for details. Also includes an attached and linked render buffer in texture._frameBuffer. RenderTextures can be thought of as an internal canvas on the GPU that can be drawn to.

Parameters:

w Number

The width of the texture in pixels.
h Number

The height of the texture in pixels.

Returns:

Texture:

the basic texture instance with a render buffer property.

`getStage`

() deprecated

Inherited from DisplayObject: getStage:691

Use the stage property instead.

`getTargetRenderTexture`

(

target
w
h

)

Objet

Defined in getTargetRenderTexture:1042

Render textures can't draw into themselves so any item being used for renderTextures needs two to alternate between. This function creates, gets, and toggles the render surface between the two.

NOTE: This method is mainly for internal use, though it may be useful for advanced uses.

Parameters:

target DisplayObject

The object associated with the render textures, usually a cached object.
w Number

The width to create the texture at.
h Number

The height to create the texture at.

Returns:

Objet:

`getTransformedBounds`

() Rectangle

Inherited from DisplayObject: getTransformedBounds:1166

Returns a rectangle representing this object's bounds in its parent's coordinate system (ie. with transformations applied). Objects that have been cached will return the transformed bounds of the cache.

Not all display objects can calculate their own bounds (ex. Shape). For these objects, you can use setBounds so that they are included when calculating Container bounds.

To reduce memory impact, the returned Rectangle instance may be reused internally; clone the instance or copy its values if you need to retain it.

Container instances calculate aggregate bounds for all children that return bounds via getBounds.

Returns:

Rectangle:

A Rectangle instance representing the bounds, or null if bounds are not available for this object.

`globalToLocal`

(

x
y
[pt]

)

Point

Inherited from DisplayObject: globalToLocal:921

Transforms the specified x and y position from the global (stage) coordinate space to the coordinate space of the display object. For example, this could be used to determine the current mouse position within the display object. Returns a Point instance with x and y properties correlating to the transformed position in the display object's coordinate space.

Example

 displayObject.x = 300;
 displayObject.y = 200;
 stage.addChild(displayObject);
 var point = displayObject.globalToLocal(100, 100);
 // Results in x=-200, y=-100

Parameters:

x Number

The x position on the stage to transform.
y Number

The y position on the stage to transform.
[pt] Point | Object optional

An object to copy the result into. If omitted a new Point object with x/y properties will be returned.

Returns:

Point:

A Point instance with x and y properties correlating to the transformed position in the display object's coordinate space.

`hasEventListener`

(

type

)

Boolean

Inherited from EventDispatcher: hasEventListener:339

Indicates whether there is at least one listener for the specified event type.

Parameters:

type String

The string type of the event.

Returns:

Boolean:

Returns true if there is at least one listener for the specified event.

`hitTest`

(

)

Boolean

Inherited from DisplayObject but overwritten in hitTest:450

Tests whether the display object intersects the specified local point (ie. draws a pixel with alpha > 0 at the specified position). This ignores the alpha, shadow and compositeOperation of the display object, and all transform properties including regX/Y.

Parameters:

x Number

The x position to check in the display object's local coordinates.
y Number

The y position to check in the display object's local coordinates.

Returns:

Boolean:

A Boolean indicating whether there is a visible section of a DisplayObject that overlaps the specified coordinates.

`initialize`

() deprecated

Inherited from Container: initialize:128

Deprecated: in favour of `createjs.promote()`

Constructor alias for backwards compatibility. This method will be removed in future versions. Subclasses should be updated to use Utility Methods/extends.

`isVisible`

() Boolean

Inherited from DisplayObject but overwritten in isVisible:136

Returns true or false indicating whether the display object would be visible if drawn to a canvas. This does not account for whether it would be visible within the boundaries of the stage.

NOTE: This method is mainly for internal use, though it may be useful for advanced uses.

Returns:

Boolean:

Boolean indicating whether the display object would be visible if drawn to a canvas

`isWebGLActive`

(

ctx

)

Boolean static

Defined in isWebGLActive:503

Test a context to see if it has WebGL enabled on it.

Parameters:

ctx CanvasContext

The context to test

Returns:

Boolean:

Whether WebGL is enabled

`localToGlobal`

(

x
y
[pt]

)

Point

Inherited from DisplayObject: localToGlobal:896

Transforms the specified x and y position from the coordinate space of the display object to the global (stage) coordinate space. For example, this could be used to position an HTML label over a specific point on a nested display object. Returns a Point instance with x and y properties correlating to the transformed coordinates on the stage.

Example

 displayObject.x = 300;
 displayObject.y = 200;
 stage.addChild(displayObject);
 var point = displayObject.localToGlobal(100, 100);
 // Results in x=400, y=300

Parameters:

x Number

The x position in the source display object to transform.
y Number

The y position in the source display object to transform.
[pt] Point | Object optional

An object to copy the result into. If omitted a new Point object with x/y properties will be returned.

Returns:

Point:

A Point instance with x and y properties correlating to the transformed coordinates on the stage.

`localToLocal`

(

x
y
target
[pt]

)

Point

Inherited from DisplayObject: localToLocal:946

Transforms the specified x and y position from the coordinate space of this display object to the coordinate space of the target display object. Returns a Point instance with x and y properties correlating to the transformed position in the target's coordinate space. Effectively the same as using the following code with localToGlobal and globalToLocal.

 var pt = this.localToGlobal(x, y);
 pt = target.globalToLocal(pt.x, pt.y);

Parameters:

x Number

The x position in the source display object to transform.
y Number

The y position on the source display object to transform.
target DisplayObject

The target display object to which the coordinates will be transformed.
[pt] Point | Object optional

An object to copy the result into. If omitted a new Point object with x/y properties will be returned.

Returns:

Point:

Returns a Point instance with x and y properties correlating to the transformed position in the target's coordinate space.

`off`

(

type
listener
[useCapture]

)

Inherited from EventDispatcher: off:249

A shortcut to the removeEventListener method, with the same parameters and return value. This is a companion to the .on method.

IMPORTANT: To remove a listener added with on, you must pass in the returned wrapper function as the listener. See on for an example.

Parameters:

type String

The string type of the event.
listener Function | Object

The listener function or object.
[useCapture] Boolean optional

For events that bubble, indicates whether to listen for the event in the capture or bubbling/target phase.

`on`

(

type
listener
[scope]
[once=false]
[data]
[useCapture=false]

)

Function

Inherited from EventDispatcher: on:173

A shortcut method for using addEventListener that makes it easier to specify an execution scope, have a listener only run once, associate arbitrary data with the listener, and remove the listener.

This method works by creating an anonymous wrapper function and subscribing it with addEventListener. The wrapper function is returned for use with removeEventListener (or off).

IMPORTANT: To remove a listener added with on, you must pass in the returned wrapper function as the listener, or use remove. Likewise, each time you call on a NEW wrapper function is subscribed, so multiple calls to on with the same params will create multiple listeners.

Example

    var listener = myBtn.on("click", handleClick, null, false, {count:3});
    function handleClick(evt, data) {
        data.count -= 1;
        console.log(this == myBtn); // true - scope defaults to the dispatcher
        if (data.count == 0) {
            alert("clicked 3 times!");
            myBtn.off("click", listener);
            // alternately: evt.remove();
        }
    }

Parameters:

type String

The string type of the event.
listener Function | Object

An object with a handleEvent method, or a function that will be called when the event is dispatched.
[scope] Object optional

The scope to execute the listener in. Defaults to the dispatcher/currentTarget for function listeners, and to the listener itself for object listeners (ie. using handleEvent).
[once=false] Boolean optional

If true, the listener will remove itself after the first time it is triggered.
[data] optional

Arbitrary data that will be included as the second parameter when the listener is called.
[useCapture=false] Boolean optional

For events that bubble, indicates whether to listen for the event in the capture or bubbling/target phase.

Returns:

Function:

Returns the anonymous function that was created and assigned as the listener. This is needed to remove the listener later using .removeEventListener.

`protectTextureSlot`

(

id
[lock=false]

)

Defined in protectTextureSlot:1023

Blocks, or frees a texture "slot" on the GPU. Can be useful if you are overflowing textures. When overflowing textures they are re-uploaded to the GPU every time they're encountered, this can be expensive with large textures. By blocking the slot you reduce available slots, potentially increasing draw calls, but mostly you prevent a texture being re-uploaded if it would have moved slots due to overflow.

NOTE: This method is mainly for internal use, though it may be useful for advanced uses. For example, block the slot a background image is stored in so there is less re-loading of that image.

Parameters:

id Number

The slot to be affected
[lock=false] Boolean optional

Whether this slot is the one being locked.

`purgeTextures`

(

[count=100]

)

Defined in purgeTextures:1161

Similar to ReleaseTexture, but this function differs by searching for textures to release. It works by assuming that it can purge any texture which was last used more than "count" draw calls ago. Because this process is unaware of the objects and whether they may be used later on your stage, false positives can occur. It is recommended to manually manage your memory with releaseTexture, however, there are many use cases where this is simpler and error-free. This process is also run by default under the hood to prevent leaks. To disable it see the autoPurge property.

Parameters:

[count=100] Number optional

How many renders ago the texture was last used

`releaseTexture`

(

item
safe

)

Defined in releaseTexture:1086

For every image encountered StageGL registers and tracks it automatically. This tracking can cause memory leaks if not purged. StageGL, by default, automatically purges them. This does have a cost and may unfortunately find false positives. This function is for manual management of this memory instead of the automatic system controlled by the autoPurge property.

This function will recursively remove all textures found on the object, its children, cache, etc. It will uncache objects and remove any texture it finds REGARDLESS of whether it is currently in use elsewhere. It is up to the developer to ensure that a texture in use is not removed.

Textures in use, or to be used again shortly, should not be removed. This is simply for performance reasons. Removing a texture in use will cause the texture to have to be re-uploaded slowing rendering.

Parameters:

item DisplayObject | Texture | Image | Canvas

An object that used the texture to be discarded.
safe Boolean

Should the release attempt to be "safe" and only delete this usage.

`removeAllChildren`

()

Inherited from Container: removeAllChildren:305

Removes all children from the display list.

Example

container.removeAllChildren();

`removeAllEventListeners`

(

[type]

)

Inherited from EventDispatcher: removeAllEventListeners:263

Removes all listeners for the specified type, or all listeners of all types.

Example

 // Remove all listeners
 displayObject.removeAllEventListeners();

 // Remove all click listeners
 displayObject.removeAllEventListeners("click");

Parameters:

[type] String optional

The string type of the event. If omitted, all listeners for all types will be removed.

`removeChild`

(

child

)

Boolean

Inherited from Container: removeChild:249

Removes the specified child from the display list. Note that it is faster to use removeChildAt() if the index is already known.

Example

 container.removeChild(child);

You can also remove multiple children:

 removeChild(child1, child2, ...);

Returns true if the child (or children) was removed, or false if it was not in the display list.

Parameters:

child DisplayObject

The child to remove.

Returns:

Boolean:

true if the child (or children) was removed, or false if it was not in the display list.

`removeChildAt`

(

index

)

Boolean

Inherited from Container but overwritten in removeChildAt:276

Removes the child at the specified index from the display list, and sets its parent to null.

Example

 container.removeChildAt(2);

You can also remove multiple children:

 container.removeChild(2, 7, ...)

Returns true if the child (or children) was removed, or false if any index was out of range.

Parameters:

index Number

The index of the child to remove.

Returns:

Boolean:

true if the child (or children) was removed, or false if any index was out of range.

`removeEventListener`

(

type
listener
[useCapture]

)

Inherited from EventDispatcher: removeEventListener:219

Removes the specified event listener.

Important Note: that you must pass the exact function reference used when the event was added. If a proxy function, or function closure is used as the callback, the proxy/closure reference must be used - a new proxy or closure will not work.

Example

 displayObject.removeEventListener("click", handleClick);

Parameters:

type String

The string type of the event.
listener Function | Object

The listener function or object.
[useCapture] Boolean optional

For events that bubble, indicates whether to listen for the event in the capture or bubbling/target phase.

`resizeTexture`

(

texture
[width=1]
[height=1]

)

protected

Defined in resizeTexture:1318

Resizes a supplied texture element. May generate invalid textures in some error cases such as; when the texture is too large, when an out of texture memory error occurs, or other error scenarios. Trying to use an invalid texture can cause renders to hard stop on some devices. Check the WebGL bound texture after running this function.

NOTE: The supplied texture must have been made with the WebGL "texImage2D" function, all default APIs in StageGL use this, so this note only matters for library developers and plugins.

Parameters:

texture WebGLTexture

The GL Texture to be modified.
[width=1] Uint optional

The width of the texture in pixels, defaults to 1
[height=1] Uint optional

The height of the texture in pixels, defaults to 1

`set`

(

props

)

DisplayObject chainable

Inherited from DisplayObject: set:1082

Provides a chainable shortcut method for setting a number of properties on the instance.

Example

 var myGraphics = new createjs.Graphics().beginFill("#ff0000").drawCircle(0, 0, 25);
 var shape = stage.addChild(new Shape()).set({graphics:myGraphics, x:100, y:100, alpha:0.5});

Parameters:

props Object

A generic object containing properties to copy to the DisplayObject instance.

Returns:

DisplayObject:

Returns the instance the method is called on (useful for chaining calls.)

`setBounds`

(

x
y
width
height

)

Inherited from DisplayObject: setBounds:1185

Allows you to manually specify the bounds of an object that either cannot calculate their own bounds (ex. Shape & Text) for future reference, or so the object can be included in Container bounds. Manually set bounds will always override calculated bounds.

The bounds should be specified in the object's local (untransformed) coordinates. For example, a Shape instance with a 25px radius circle centered at 0,0 would have bounds of (-25, -25, 50, 50).

Parameters:

x Number

The x origin of the bounds. Pass null to remove the manual bounds.
y Number

The y origin of the bounds.
width Number

The width of the bounds.
height Number

The height of the bounds.

`setChildIndex`

(

child
index

)

Inherited from Container: setChildIndex:418

Changes the depth of the specified child. Fails silently if the child is not a child of this container, or the index is out of range.

Parameters:

child DisplayObject
index Number

`setClearColor`

(

[color=0x00000000]

)

Defined in setClearColor:1405

Changes the webGL clear, aka "background" color to the provided value. A transparent clear is recommended, as non-transparent colours may create undesired boxes around some visuals.

The clear color will also be used for filters and other "render textures". The stage background will ignore the transparency value and display a solid color normally. For the stage to recognize and use transparency it must be created with the transparent flag set to true (see StageGL/constructor)).

Using "transparent white" to demonstrate, the valid data formats are as follows:

"#FFF"
"#FFFFFF"
"#FFFFFF00"
"rgba(255,255,255,0.0)"

Parameters:

[color=0x00000000] String | Int optional

The new color to use as the background

`setTextureParams`

(

gl
[isPOT=false]

)

Defined in setTextureParams:1386

Common utility function used to apply the correct texture processing parameters for the bound texture.

Parameters:

gl WebGLRenderingContext

The canvas WebGL context object to draw into.
[isPOT=false] Boolean optional

Marks whether the texture is "Power of Two", this may allow better quality AA.

`setTransform`

(

[x=0]
[y=0]
[scaleX=1]
[scaleY=1]
[rotation=0]
[skewX=0]
[skewY=0]
[regX=0]
[regY=0]

)

DisplayObject chainable

Inherited from DisplayObject: setTransform:968

Shortcut method to quickly set the transform properties on the display object. All parameters are optional. Omitted parameters will have the default value set.

Example

 displayObject.setTransform(100, 100, 2, 2);

Parameters:

[x=0] Number optional

The horizontal translation (x position) in pixels
[y=0] Number optional

The vertical translation (y position) in pixels
[scaleX=1] Number optional

The horizontal scale, as a percentage of 1
[scaleY=1] Number optional

the vertical scale, as a percentage of 1
[rotation=0] Number optional

The rotation, in degrees
[skewX=0] Number optional

The horizontal skew factor
[skewY=0] Number optional

The vertical skew factor
[regX=0] Number optional

The horizontal registration point in pixels
[regY=0] Number optional

The vertical registration point in pixels

Returns:

DisplayObject:

Returns this instance. Useful for chaining commands.

`sortChildren`

(

sortFunction

)

Inherited from Container: sortChildren:348

Performs an array sort operation on the child list.

Example: Display children with a higher y in front.

 var sortFunction = function(obj1, obj2, options) {
     if (obj1.y > obj2.y) { return 1; }
     if (obj1.y < obj2.y) { return -1; }
     return 0;
 }
 container.sortChildren(sortFunction);

Parameters:

sortFunction Function

the function to use to sort the child list. See JavaScript's Array.sort documentation for details.

`swapChildren`

(

child1
child2

)

Inherited from Container: swapChildren:398

Swaps the specified children's depth in the display list. Fails silently if either child is not a child of this Container.

Parameters:

child1 DisplayObject
child2 DisplayObject

`swapChildrenAt`

(

index1
index2

)

Inherited from Container: swapChildrenAt:383

Swaps the children at the specified indexes. Fails silently if either index is out of range.

Parameters:

index1 Number
index2 Number

`tick`

(

[props]

)

Inherited from Stage: tick:380

Propagates a tick event through the display list. This is automatically called by update unless tickOnUpdate is set to false.

If a props object is passed to tick(), then all of its properties will be copied to the event object that is propagated to listeners.

Some time-based features in EaselJS (for example Sprite/framerate require that a tick event object (or equivalent object with a delta property) be passed as the props parameter to tick(). For example:

Ticker.on("tick", handleTick);
function handleTick(evtObj) {
    // clone the event object from Ticker, and add some custom data to it:
    var evt = evtObj.clone().set({greeting:"hello", name:"world"});

    // pass it to stage.update():
    myStage.update(evt); // subsequently calls tick() with the same param
}

// ...
myDisplayObject.on("tick", handleDisplayObjectTick);
function handleDisplayObjectTick(evt) {
    console.log(evt.delta); // the delta property from the Ticker tick event object
    console.log(evt.greeting, evt.name); // custom data: "hello world"
}

Parameters:

[props] Object optional

An object with properties that should be copied to the event object. Should usually be a Ticker event object, or similar object with a delta property.

`toDataURL`

(

[backgroundColor]
[mimeType="image/png"]

)

String

Inherited from Stage: toDataURL:449

Returns a data url that contains a Base64-encoded image of the contents of the stage. The returned data url can be specified as the src value of an image element.

Parameters:

[backgroundColor] String optional

The background color to be used for the generated image. Any valid CSS color value is allowed. The default value is a transparent background.
[mimeType="image/png"] String optional

The MIME type of the image format to be create. The default is "image/png". If an unknown MIME type is passed in, or if the browser does not support the specified MIME type, the default value will be used.

Returns:

String:

a Base64 encoded image.

`toString`

() String

Inherited from EventDispatcher but overwritten in toString:560

Returns a string representation of this object.

Returns:

String:

a string representation of the instance.

`uncache`

()

Inherited from DisplayObject: uncache:875

Clears the current cache. See cache for more information.

`update`

(

[props]

)

Inherited from Stage: update:349

Each time the update method is called, the stage will call tick unless tickOnUpdate is set to false, and then render the display list to the canvas.

Parameters:

[props] Object optional

Props object to pass to tick(). Should usually be a Ticker event object, or similar object with a delta property.

`updateCache`

(

compositeOperation

)

Inherited from DisplayObject: updateCache:846

Redraws the display object to its cache. Calling updateCache without an active cache will throw an error. If compositeOperation is null the current cache will be cleared prior to drawing. Otherwise the display object will be drawn over the existing cache using the specified compositeOperation.

Example

Clear the current graphics of a cached shape, draw some new instructions, and then update the cache. The new line will be drawn on top of the old one.

 // Not shown: Creating the shape, and caching it.
 shapeInstance.clear();
 shapeInstance.setStrokeStyle(3).beginStroke("#ff0000").moveTo(100, 100).lineTo(200,200);
 shapeInstance.updateCache();

In previous versions caching was handled on DisplayObject but has since been moved to BitmapCache. This allows for easier interaction and alternate cache methods like WebGL and StageGL.

Parameters:

compositeOperation String

The compositeOperation to use, or null to clear the cache and redraw it. whatwg spec on compositing.

`updateContext`

(

ctx

)

Inherited from DisplayObject: updateContext:771

Applies this display object's transformation, alpha, globalCompositeOperation, clipping path (mask), and shadow to the specified context. This is typically called prior to draw.

Parameters:

ctx CanvasRenderingContext2D

The canvas 2D to update.

`updateSimultaneousTextureCount`

(

[count=1]

)

Defined in updateSimultaneousTextureCount:1193

Try to set the max textures the system can handle. It should default to the hardware maximum, and lower values may limit performance. Some devices have been known to mis-report their max textures, or you may need a standard baseline cross devices for testing. Barring the previous suggestions, there is little need to call this function as the library will automatically try to find the best value.

NOTE: This method is mainly for internal use, though it may be useful for advanced uses.

Parameters:

[count=1] Number optional

The number of textures intended for simultaneous loading.

`updateViewport`

(

width
height

)

Defined in updateViewport:1230

Update the WebGL viewport. Note that this does not update the canvas element's width/height, but the render surface's instead. This is necessary after manually resizing the canvas element on the DOM to avoid a up/down scaled render.

Parameters:

width Integer

The width of the render surface in pixels.
height Integer

The height of the render surface in pixels.

`willTrigger`

(

type

)

Boolean

Inherited from EventDispatcher: willTrigger:350

Indicates whether there is at least one listener for the specified event type on this object or any of its ancestors (parent, parent's parent, etc). A return value of true indicates that if a bubbling event of the specified type is dispatched from this object, it will trigger at least one listener.

This is similar to hasEventListener, but it searches the entire event flow for a listener, not just this object.

Parameters:

type String

The string type of the event.

Returns:

Defined in _baseTextures:355

An array of all the simple filler textures used to prevent issues with missing textures in a batch.

`_batchId`

Number protected

Defined in _batchId:388

The current batch being drawn, A batch consists of a call to drawElements on the GPU. Many of these calls can occur per draw.

Default: 0

`_batchTextureCount`

Number protected

Defined in _batchTextureCount:363

The number of concurrent textures the GPU can handle. This value is dynamically set from WebGL during initialization via gl.getParameter(gl.MAX_TEXTURE_IMAGE_UNITS). The WebGL spec states that the lowest guaranteed value is 8, but it could be higher. Do not set this value higher than the value returned by the GPU. Setting it lower will probably reduce performance, but may be advisable to reserve slots for custom filter work. NOTE: Can also act as a length for {{#crossLink "StageGL/_batchTextures:property"}}.

Default: 8

`_batchTextures`

Array protected

Defined in _batchTextures:347

An array of all the textures currently loaded into the GPU. The index in the array matches the GPU index.

`_bounds`

Rectangle protected

Inherited from DisplayObject: _bounds:446

Default: null

`_cacheContainer`

Container protected

Defined in _cacheContainer:445

Used to counter-position the object being cached so it aligns with the cache surface. Additionally ensures that all rendering starts with a top level container.

Default: An instance of an EaselJS Container.

`_cacheDataURL`

String deprecated protected

Inherited from DisplayObject: _cacheDataURL:421

Moved to BitmapCache

Default: null

`_cacheDataURLID`

Number deprecated protected

Inherited from DisplayObject: _cacheDataURLID:412

Moved to BitmapCache

Default: 0

`_cacheScale`

Number deprecated protected

Inherited from DisplayObject: _cacheScale:403

Moved to BitmapCache

Default: 1

`_captureListeners`

Object protected

Inherited from EventDispatcher: _captureListeners:106

`_clearColor`

Object protected

Defined in _clearColor:230

The color to use when the WebGL canvas has been cleared. May appear as a background color. Defaults to grey.

Default: {r: 0.50, g: 0.50, b: 0.50, a: 0.00}

`_drawID`

Number protected

Defined in _drawID:398

The current draw being performed, may contain multiple batches. Comparing to StageGL/_batchID:property can reveal batching efficiency.

Default: 0

`_drawTexture`

Array protected

Defined in _drawTexture:330

An index based lookup of every WebGL Texture currently in use.

`_indices`

Float32Array protected

Defined in _indices:294

The vertex indices data for the current draw call.

Default: null

`_isDrawing`

Number protected

Defined in _isDrawing:416

Used to prevent nested draw calls from accidentally overwriting drawing information by tracking depth.

Default: 0

`_lastTextureInsert`

Number protected

Defined in _lastTextureInsert:376

The location at which the last texture was inserted into a GPU slot in _batchTextures. Manual control of this variable can yield improvements in performance by intelligently replacing textures inside a batch to reduce texture re-load. It is impossible to write automated general use code, as it requires display list look ahead inspection and/or render foreknowledge.

Default: -1

`_lastTrackedCanvas`

Number protected

Defined in _lastTrackedCanvas:425

Used to ensure every canvas used as a texture source has a unique ID.

Default: 0

`_listeners`

Object protected

Inherited from EventDispatcher: _listeners:99

`_maxCardsPerBatch`

Number protected

Defined in _maxCardsPerBatch:239

The maximum number of cards (aka a single sprite) that can be drawn in one draw call. Use getter/setters to modify otherwise internal buffers may be incorrect sizes.

Default: StageGL.DEFAULT_MAX_BATCH_SIZE (10000)

`_mouseOverIntervalID`

Number protected

Inherited from Stage: _mouseOverIntervalID:207

`_nextStage`

Stage protected

Inherited from Stage: _nextStage:214

`_pointerCount`

Object private

Inherited from Stage: _pointerCount:191

Number of active pointers.

`_pointerData`

Object private

Inherited from Stage: _pointerData:182

Holds objects with data for each active pointer id. Each object has the following properties: x, y, event, target, overTarget, overX, overY, inBounds, posEvtObj (native event that last updated position)

`_premultiply`

Boolean protected

Defined in _premultiply:174

Specifies whether or not StageGL is handling colours as premultiplied alpha.

Default: false

`_preserveBuffer`

Boolean protected

Defined in _preserveBuffer:145

Specifies whether or not the canvas is auto-cleared by WebGL. The WebGL spec discourages true. If true, the canvas is NOT auto-cleared by WebGL. Used when the canvas context is created and requires context re-creation to update.

Default: false

`_prevStage`

Stage protected

Inherited from Stage: _prevStage:221

`_primaryPointerID`

Object private

Inherited from Stage: _primaryPointerID:199

The ID of the primary pointer.

`_projectionMatrix`

Float32Array protected

`autoClear`

Boolean

Inherited from Stage: autoClear:69

Indicates whether the stage should automatically clear the canvas before each render. You can set this to false to manually control clearing (for generative art, or when pointing multiple stages at the same canvas for example).

Example

 var stage = new createjs.Stage("canvasId");
 stage.autoClear = false;

Default: true

`autoPurge`

Integer protected

Defined in autoPurge:879

Specifies whether or not StageGL is automatically purging unused textures. Higher numbers purge less often. Values below 10 are upgraded to 10, and -1 disables this feature.

Default: 1000

`bitmapCache`

BitmapCache readonly

Inherited from DisplayObject: bitmapCache:165

If a cache has been made, this returns the class that is managing the cacheCanvas and its properties. See BitmapCache for more information. Use this to control, inspect, and change the cache. In special circumstances this may be a modified or subclassed BitmapCache.

Default: null

`cacheCanvas`

HTMLCanvasElement | Object readonly

Inherited from DisplayObject: cacheCanvas:155

If a cache is active, this returns the canvas that holds the image of this display object. See cache for more information. Use this to display the result of a cache. This will be a HTMLCanvasElement unless special cache rules have been deliberately enabled for this cache.

Default: null

`cacheID`

Number deprecated

Inherited from DisplayObject: cacheID:706

Returns an ID number that uniquely identifies the current cache for this display object. This can be used to determine if the cache has changed since a previous check. Moved to BitmapCache

Default: 0

`canvas`

HTMLCanvasElement | Object

Inherited from Stage: canvas:85

The canvas the stage will render to. Multiple stages can share a single canvas, but you must disable autoClear for all but the first stage that will be ticked (or they will clear each other's render).

When changing the canvas property you must disable the events on the old canvas, and enable events on the new canvas or mouse events will not work as expected. For example:

 myStage.enableDOMEvents(false);
 myStage.canvas = anotherCanvas;
 myStage.enableDOMEvents(true);

`children`

Array

Inherited from Container: children:61

The array of children in the display list. You should usually use the child management methods such as addChild, removeChild, swapChildren, etc, rather than accessing this directly, but it is included for advanced uses.

Default: null

`compositeOperation`

String

`DEFAULT_MAX_BATCH_SIZE`

Number final static readonly

Defined in DEFAULT_MAX_BATCH_SIZE:539

The default value for the maximum number of cards we want to process in a batch. See WEBGL_MAX_INDEX_NUM for a hard limit.

Default: 10000

`drawRect`

Rectangle

Inherited from Stage: drawRect:119

Specifies the area of the stage to affect when calling update. This can be use to selectively re-draw specific regions of the canvas. If null, the whole canvas area is drawn.

`filters`

Array

Inherited from DisplayObject: filters:355

An array of Filter objects to apply to this display object. Filters are only applied / updated when Cache or UpdateCache is called on the display object, and only apply to the area that is cached.

Default: null

`handleEvent`

Function

Inherited from Stage: handleEvent:422

Default event handler that calls the Stage update method when a tick event is received. This allows you to register a Stage instance as a event listener on Ticker directly, using:

 Ticker.addEventListener("tick", myStage);

Note that if you subscribe to ticks using this pattern, then the tick event object will be passed through to display object tick handlers, instead of delta and paused parameters.

`hitArea`

DisplayObject

Inherited from DisplayObject but overwritten in hitArea:173

The hitArea property is not supported for Stage.

Default: null

`id`

Number

Inherited from DisplayObject: id:175

Unique ID for this display object. Makes display objects easier for some uses.

Default: -1

`INDICIES_PER_CARD`

Number final static readonly

Defined in INDICIES_PER_CARD:528

The number of triangle indices it takes to form a Card. 3 per triangle, 2 triangles.

Default: 6

`isCacheControlled`

Boolean protected

Defined in isCacheControlled:434

Controls whether final rendering output of a CacheDraw is the canvas or a render texture. See the Cache function modifications for full implications and discussion.

Default: false

`isWebGL`

Boolean readonly

Defined in isWebGL:870

Indicates whether WebGL is being used for rendering. For example, this would be false if WebGL is not supported in the browser.

`mask`

Shape

Inherited from DisplayObject: mask:365

A Shape instance that defines a vector mask (clipping path) for this display object. The shape's transformation will be applied relative to the display object's parent coordinates (as if it were a child of the parent).

Default: null

`mouseChildren`

Boolean

Inherited from Container: mouseChildren:72

Indicates whether the children of this container are independently enabled for mouse/pointer interaction. If false, the children will be aggregated under the container - for example, a click on a child shape would trigger a click event on the container.

Default: true

`mouseEnabled`

Boolean

Inherited from DisplayObject: mouseEnabled:183

Indicates whether to include this object when running mouse interactions. Setting this to false for children of a Container will cause events on the Container to not fire when that child is clicked. Setting this property to false does not prevent the getObjectsUnderPoint method from returning the child.

Note: In EaselJS 0.7.0, the mouseEnabled property will not work properly with nested Containers. Please check out the latest NEXT version in GitHub for an updated version with this issue resolved. The fix will be provided in the next release of EaselJS.

Default: true

`mouseInBounds`

Boolean

Inherited from Stage: mouseInBounds:137

Indicates whether the mouse is currently within the bounds of the canvas.

Default: false

`mouseMoveOutside`

Boolean

Inherited from Stage: mouseMoveOutside:153

If true, mouse move events will continue to be called when the mouse leaves the target canvas. See mouseInBounds, and MouseEvent x/y/rawX/rawY.

Default: false

`mouseX`

Number readonly

Inherited from Stage: mouseX:101

The current mouse X position on the canvas. If the mouse leaves the canvas, this will indicate the most recent position over the canvas, and mouseInBounds will be set to false.

`mouseY`

Number readonly

Inherited from Stage: mouseY:110

The current mouse Y position on the canvas. If the mouse leaves the canvas, this will indicate the most recent position over the canvas, and mouseInBounds will be set to false.

`name`

String

Inherited from DisplayObject: name:208

An optional name for this display object. Included in toString . Useful for debugging.

Default: null

`nextStage`

Stage

Inherited from Stage: nextStage:302

Specifies a target stage that will have mouse / touch interactions relayed to it after this stage handles them. This can be useful in cases where you have multiple layered canvases and want user interactions events to pass through. For example, this would relay mouse events from topStage to bottomStage:

 topStage.nextStage = bottomStage;

To disable relaying, set nextStage to null.

MouseOver, MouseOut, RollOver, and RollOut interactions are also passed through using the mouse over settings of the top-most stage, but are only processed if the target stage has mouse over interactions enabled. Considerations when using roll over in relay targets:

The top-most (first) stage must have mouse over interactions enabled (via enableMouseOver)

All stages that wish to participate in mouse over interaction must enable them via enableMouseOver

All relay targets will share the frequency value of the top-most stage

To illustrate, in this example the targetStage would process mouse over interactions at 10hz (despite passing 30 as it's desired frequency): topStage.nextStage = targetStage; topStage.enableMouseOver(10); targetStage.enableMouseOver(30);

If the target stage's canvas is completely covered by this stage's canvas, you may also want to disable its DOM events using:

targetStage.enableDOMEvents(false);

`numChildren`

Number readonly

Inherited from Container: numChildren:114

Returns the number of children in the container.

`parent`

Container final readonly

Inherited from DisplayObject: parent:217

A reference to the Container or Stage object that contains this display object, or null if it has not been added to one.

Default: null

`PARTICLE_FRAGMENT_BODY`

String final static readonly

Defined in PARTICLE_FRAGMENT_BODY:746

`PARTICLE_VERTEX_BODY`

String final static readonly

Defined in PARTICLE_VERTEX_BODY:735

`preventSelection`

Boolean

Stage readonly

Inherited from DisplayObject: stage:699

Returns the Stage instance that this display object will be rendered on, or null if it has not been added to one.

`tickChildren`

Boolean

Inherited from Container: tickChildren:82

If false, the tick will not be propagated to children of this Container. This can provide some performance benefits. In addition to preventing the "tick" event from being dispatched, it will also prevent tick related updates on some display objects (ex. Sprite & MovieClip frame advancing, DOMElement visibility handling).

Default: true

`tickEnabled`

Boolean

Inherited from DisplayObject: tickEnabled:198

If false, the tick will not run on this display object (or its children). This can provide some performance benefits. In addition to preventing the "tick" event from being dispatched, it will also prevent tick related updates on some display objects (ex. Sprite & MovieClip frame advancing, and DOMElement display properties).

Default: true

`tickOnUpdate`

Boolean

Inherited from Stage: tickOnUpdate:145

If true, tick callbacks will be called on all display objects on the stage prior to rendering to the canvas.

Default: true

`transformMatrix`

Matrix2D

Inherited from DisplayObject: transformMatrix:324

If set, defines the transformation for this display object, overriding all other transformation properties (x, y, rotation, scale, skew).

Default: null

`UV_RECT`

Object final static readonly

Defined in UV_RECT:563

Default U/V rect for dealing with full coverage from an image source.

Default: {t:0, l:0, b:1, r:1}

`VERTEX_PROPERTY_COUNT`

Number final static readonly

Defined in VERTEX_PROPERTY_COUNT:517

The number of properties defined per vertex (x, y, textureU, textureV, textureIndex, alpha)

Default: 6

`visible`

Boolean

Inherited from DisplayObject: visible:300

Indicates whether this display object should be rendered to the canvas and included when running the Stage getObjectsUnderPoint method.

Default: true

`vocalDebug`

Boolean

Defined in vocalDebug:135

Console log potential issues and problems. This is designed to have minimal performance impact, so if extensive debugging information is required, this may be inadequate. See WebGLInspector

Default: false

`WEBGL_MAX_INDEX_NUM`

Number final static readonly

Defined in WEBGL_MAX_INDEX_NUM:551

The maximum size WebGL allows for element index numbers. Uses a 16 bit unsigned integer. It takes 6 indices to make a unique card.

Default: 65536

`x`

Number

Inherited from DisplayObject: x:309

The x (horizontal) position of the display object, relative to its parent.

Default: 0

`y`

Number

Inherited from DisplayObject: y:317

Default: 0

Events

`added`

Inherited from DisplayObject: added:651

Dispatched when the display object is added to a parent container.

`click`

Inherited from DisplayObject: click:549

Available since 0.6.0

Dispatched when the user presses their left mouse button and then releases it while over the display object. See the MouseEvent class for a listing of event properties.

`dblclick`

Inherited from DisplayObject: dblclick:556

Available since 0.6.0

Dispatched when the user double clicks their left mouse button over this display object. See the MouseEvent class for a listing of event properties.

`drawend`

Inherited from Stage but overwritten in drawend:847

Dispatched each update immediately after the display list is drawn to the canvas and the canvas context is restored.

Inherited from DisplayObject: pressmove:621

Available since 0.7.0

However, with a listener for "rollover" instead, only a single event is received when the mouse first enters the aggregate myContainer content (target=myContainer).

This event must be enabled using enableMouseOver. See the MouseEvent class for a listing of event properties.

`stagemousedown`

Inherited from Stage: stagemousedown:242

Available since 0.6.0

Dispatched when the user presses their left mouse button on the canvas. See the MouseEvent class for a listing of event properties.

`stagemousemove`

Inherited from Stage: stagemousemove:235

Available since 0.6.0

Dispatched when the user moves the mouse over the canvas. See the MouseEvent class for a listing of event properties.

`stagemouseup`

Inherited from Stage: stagemouseup:249

Available since 0.6.0

Dispatched when the user the user presses somewhere on the stage, then releases the mouse button anywhere that the page can detect it (this varies slightly between browsers). You can use mouseInBounds to check whether the mouse is currently within the stage bounds. See the MouseEvent class for a listing of event properties.

`tick`

Inherited from DisplayObject: tick:661

Available since 0.6.0

Dispatched on each display object on a stage whenever the stage updates. This occurs immediately before the rendering (draw) pass. When update is called, first all display objects on the stage dispatch the tick event, then all of the display objects are drawn to stage. Children will have their Tick:event event dispatched in order of their depth prior to the event being dispatched on their parent.

Event Payload:

target Object

The object that dispatched the event.
type String

The event type.
params Array

An array containing any arguments that were passed to the Stage.update() method. For example if you called stage.update("hello"), then the params would be ["hello"].

`tickend`

Inherited from Stage: tickend:280

Available since 0.7.0

Dispatched each update immediately after the tick event is propagated through the display list. Does not fire if tickOnUpdate is false. Precedes the "drawstart" event.

`tickstart`

Inherited from Stage: tickstart:273

Available since 0.7.0

Dispatched each update immediately before the tick event is propagated through the display list. You can call preventDefault on the event object to cancel propagating the tick event.