Class: OffscreenLayerGL

(abstract) Rendering.WebGL.OffscreenLayerGL(inkContext, options)

Storage for a bitmap data that can be manipulated or presented on the screen.It corresponds to a GL texture or a render buffer.It defines the ration between actual pixels and the abstract layer dimensions.Not constructable. InkCanvas creates such layers.

Constructor

(abstract) new OffscreenLayerGL(inkContext, options)

Parameters:

Name	Type	Description
inkContext	Rendering.InkContext
options	Rendering.WebGL.InkLayerOptions

Properties:

Name	Type	Description
canvas	Rendering.WebGL.InkCanvasGL	Ink canvas reference
bounds	Common.Rect	The bounds of the layer. Equals to (0, 0, width, height).

Since:

• version 1.3

Extends

• Rendering.WebGL.InkLayer

Methods

blend(source, options)

Draws the content of the 'source'. The 'source' must use a texture storage.

Parameters:

Name	Type	Description
source	Rendering.WebGL.OffscreenLayerGL	layer to be drawn
options	Rendering.BlendOptions	blending configuration

clear(shapeopt, coloropt)

Clears layer area with a color

Parameters:

Name	Type	Attributes	Default	Description
shape	Common.Rect|Polygon|PathBuilding.InkPath2D|Common.Color	<optional>	bounds	Area to clear
color	Common.Color	<optional>	TRANSPERENT

createImageData(pixels, rect) → {ImageData}

Creates image data object

Parameters:

Name	Type	Description
pixels	Uint8ClampedArray	Image data pixel values
rect	Common.Rect

Returns:

Pixels image data

Type

ImageData

delete()

Release allocated WebGL resources

Overrides:

• Rendering.WebGL.InkLayer#delete

draw(Stroke) → Common.Rect

Draws points with a brush over the layer

Parameters:

Name	Type	Description
Stroke	Stroke	model instance

Returns:

Affected area

Type

Common.Rect

drawStroke(brush, path, drawContext, matrixopt) → Common.Rect

Draws points with a brush over the layer

Parameters:

Name	Type	Attributes	Description
brush	Rendering.WebGL.BrushGL|Rendering.2D.Brush2D		Brush instance determines how the stroke is going to be rendered
path	PathBuilding.InterpolatedSpline		Spline to draw
drawContext	Rendering.WebGL.StrokeDrawContext|Common.Color		StrokeDrawContext instance (contains previous path point), applicable only when brush is BrushGL
matrix	Common.Matrix	<optional>	Transforms drawing context

Returns:

affected area

Type

Common.Rect

fill(shape, antiAliasingopt) → Common.Rect

Fills shape with color

Parameters:

Name	Type	Attributes	Default	Description
shape	PathBuilding.PolygonArray|PathBuilding.Polygon|Polygon|Rect			Control points to work with it
antiAliasing	boolean	<optional>	true	is anti aliasing is enabled

Returns:

affected area

Type

Common.Rect

(async, abstract) getExportCanvas()

Overrides:

• Rendering.WebGL.InkLayer#getExportCanvas

(async) getImageData(rectopt, postDivideAlphaopt) → {ImageData}

Read pixels data

Parameters:

Name	Type	Attributes	Default	Description
rect	Common.Rect	<optional>	bounds	Area to read
postDivideAlpha	boolean	<optional>	false	Recover color from GL premultiplyed color transform, should be true when result targets 2D context

Returns:

Pixels image data

Type

ImageData

isDeleted() → {boolean}

Overrides:

• Rendering.WebGL.InkLayer#isDeleted

Returns:

Is underlying WebGL resources are deleted

Type

boolean

putImageData(imageData, xopt, yopt)

Write pixels data

Parameters:

Name	Type	Attributes	Default	Description
imageData	ImageData			An ImageData object containing the array of pixel values
x	int	<optional>	0	Horizontal position (x coordinate) at which to place the image data in the destination layer
y	int	<optional>	0	Vertical position (y coordinate) at which to place the image data in the destination layer

(async) readPixels(rectopt, postDivideAlphaopt) → {Uint8ClampedArray}

Read pixels data (async with WebGL2)

Parameters:

Name	Type	Attributes	Default	Description
rect	Common.Rect	<optional>	bounds	area to read
postDivideAlpha	boolean	<optional>	false	result pixels format uses premultiplyed alpha by default, when straight alpha pixels are needed pixels are processed

Returns:

pixels

Type

Uint8ClampedArray

resize(width, height)

Resize layer

Parameters:

Name	Type	Description
width	int
height	int

Overrides:

• Rendering.WebGL.InkLayer#resize

setTransform(matrix)

Configures ink transformation over underlying layer

Parameters:

Name	Type	Description
matrix	Common.Matrix

Overrides:

• Rendering.WebGL.InkLayer#setTransform

(async) toBlob(rectopt, mimeTypeopt, qualityopt) → {Blob}

Exports layer content. Compatible in web environment.

Parameters:

Name	Type	Attributes	Default	Description
rect	Common.Rect	<optional>	bounds	Area to read
mimeType	string	<optional>	image/png	Supported values are image/png, image/jpeg and image/webp.
quality	float	<optional>	0.92	A Number between 0 and 1 indicating image quality if the requested type is image/jpeg or image/webp.If this argument is anything else, the default values 0.92 and 0.80 are used for image/jpeg and image/webp respectively.

Overrides:

• Rendering.WebGL.InkLayer#toBlob

Returns:

Layer content

Type

Blob

(async) toBuffer(rectopt, mimeTypeopt, options) → {Buffer}

Exports layer content. Compatible in nodejs environment.

Parameters:

Name	Type	Attributes	Default	Description
rect	Common.Rect	<optional>	bounds	Area to read
mimeType	string	<optional>	image/png	Supported values are image/png and image/jpeg.
options	Rendering.Layer.PNGOptions|Rendering.Layer.JPEGOptions

Overrides:

• Rendering.WebGL.InkLayer#toBuffer

Returns:

Layer content

Type

Buffer

writePixels(data, rectopt)

Write pixels data

Parameters:

Name	Type	Attributes	Default	Description
data	Uint8ClampedArray|Uint8Array			Array of pixel values
rect	Common.Rect	<optional>	bounds	area to write

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