WebGLFilterBackend

Experimental. This object is a sort of repository of help layers used to avoid of recreating them during frequent filtering. If you are previewing a filter with a slider you probably do not want to create help layers every filter step. in this object there will be appended some canvases, created once, resized sometimes cleared never. Clearing is left to the developer.

textureCache

textureCache: TTextureCache

Defined in: src/filters/WebGLFilterBackend.ts:40

Keyed map for texture cache

tileSize

tileSize: number

Defined in: src/filters/WebGLFilterBackend.ts:12

Methods

applyFilters()

applyFilters(filters, source, width, height, targetCanvas, cacheKey?): undefined | TWebGLPipelineState

Defined in: src/filters/WebGLFilterBackend.ts:106

Attempts to apply the requested filters to the source provided, drawing the filtered output to the provided target canvas.

Parameters

filters

BaseFilter<string, Record<string, any>, Record<string, any>>[]

The filters to apply.

source

TexImageSource

The source to be filtered.

width

number

The width of the source input.

height

number

The height of the source input.

targetCanvas

HTMLCanvasElement

The destination for filtered output to be drawn.

cacheKey?

string

A key used to cache resources related to the source. If omitted, caching will be skipped.

Returns

undefined | TWebGLPipelineState

captureGPUInfo()

captureGPUInfo(): any

Defined in: src/filters/WebGLFilterBackend.ts:378

Attempt to extract GPU information strings from a WebGL context.

Useful information when debugging or blacklisting specific GPUs.

Returns

any

A GPU info object with renderer and vendor strings.

clearWebGLCaches()

clearWebGLCaches(): void

Defined in: src/filters/WebGLFilterBackend.ts:193

Wipe out WebGL-related caches.

Returns

void

copyGLTo2D()

copyGLTo2D(gl, pipelineState): void

Defined in: src/filters/WebGLFilterBackend.ts:318

Copy an input WebGL canvas on to an output 2D canvas.

The WebGL canvas is assumed to be upside down, with the top-left pixel of the desired output image appearing in the bottom-left corner of the WebGL canvas.

Parameters

gl

WebGLRenderingContext

pipelineState

TWebGLPipelineState

The 2D target canvas to copy on to.

Returns

void

copyGLTo2DPutImageData()

copyGLTo2DPutImageData(this, gl, pipelineState): void

Defined in: src/filters/WebGLFilterBackend.ts:350

Copy an input WebGL canvas on to an output 2D canvas using 2d canvas’ putImageData API. Measurably faster than using ctx.drawImage in Firefox (version 54 on OSX Sierra).

Parameters

this

Required<WebGLFilterBackend>

gl

WebGLRenderingContext

pipelineState

TWebGLPipelineState

The 2D target canvas to copy on to.

Returns

void

createTexture()

createTexture(gl, width, height, textureImageSource?, filter?): null | WebGLTexture

Defined in: src/filters/WebGLFilterBackend.ts:211

Create a WebGL texture object.

Accepts specific dimensions to initialize the texture to or a source image.

Parameters

gl

WebGLRenderingContext

The GL context to use for creating the texture.

width

number

The width to initialize the texture at.

height

number

The height to initialize the texture.

textureImageSource?

TexImageSource

A source for the texture data.

filter?

gl.NEAREST default or gl.LINEAR filters for the texture. This filter is very useful for LUTs filters. If you need interpolation use gl.LINEAR

9728 | 9729

Returns

null | WebGLTexture

createWebGLCanvas()

createWebGLCanvas(width, height): void

Defined in: src/filters/WebGLFilterBackend.ts:74

Create a canvas element and associated WebGL context and attaches them as class properties to the GLFilterBackend class.

Parameters

width

number

height

number

Returns

void

dispose()

dispose(): void

Defined in: src/filters/WebGLFilterBackend.ts:178

Detach event listeners, remove references, and clean up caches.

Returns

void

evictCachesForKey()

evictCachesForKey(cacheKey): void

Defined in: src/filters/WebGLFilterBackend.ts:302

Clear out cached resources related to a source image that has been filtered previously.

Parameters

cacheKey

string

The cache key provided when the source image was filtered.

Returns

void

getCachedTexture()

getCachedTexture(uniqueId, textureImageSource, filter?): null | WebGLTexture

Defined in: src/filters/WebGLFilterBackend.ts:271

Can be optionally used to get a texture from the cache array

If an existing texture is not found, a new texture is created and cached.

Parameters

uniqueId

string

A cache key to use to find an existing texture.

textureImageSource

TexImageSource

A source to use to create the texture cache entry if one does not already exist.

filter?

9728 | 9729

Returns

null | WebGLTexture

setupGLContext()

setupGLContext(width, height): void

Defined in: src/filters/WebGLFilterBackend.ts:65

Setup a WebGL context suitable for filtering, and bind any needed event handlers.

Parameters

width

number

height

number

Returns

void