Class: abstract BaseRenderingEngine

Base class for rendering engines that handle viewport rendering. This abstract class provides the common functionality shared between different rendering strategies

Extended by

• TiledRenderingEngine
• ContextPoolRenderingEngine

Constructors

new BaseRenderingEngine()

new BaseRenderingEngine(id?): BaseRenderingEngine

Parameters

• id?: string

Returns

BaseRenderingEngine

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:53

Properties

_animationFrameHandle

protected _animationFrameHandle: number = null

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:47

---

_animationFrameSet

protected _animationFrameSet: boolean = false

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:46

---

_needsRender

protected _needsRender: Set<string>

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:45

---

_viewports

protected _viewports: Map<string, Viewport>

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:44

---

hasBeenDestroyed

hasBeenDestroyed: boolean

A flag which tells if the renderingEngine has been destroyed or not

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:40

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id

readonly id: string

Unique identifier for renderingEngine

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:38

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offScreenCanvasContainer

offScreenCanvasContainer: HTMLDivElement

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:43

---

offscreenMultiRenderWindow

offscreenMultiRenderWindow: VtkOffscreenMultiRenderWindow

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:42

---

useCPURendering

protected useCPURendering: boolean

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:48

Methods

_getViewportsAsArray()

protected _getViewportsAsArray(): Viewport[]

Returns

Viewport[]

Array of viewports.

Method

_getViewportsAsArray Returns an array of all viewports

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:676

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_renderFlaggedViewports()

abstract protected _renderFlaggedViewports(): void

Renders all viewports. This method must be implemented by subclasses to define their specific rendering strategy

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:813

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_renderViewportFromVtkCanvasToOnscreenCanvas()

abstract protected _renderViewportFromVtkCanvasToOnscreenCanvas(viewport, offScreenCanvas): ImageRenderedEventDetail

Renders a particular Viewport's on screen canvas. This method must be implemented by subclasses to define how to copy from the offscreen canvas to the onscreen canvas.

Parameters

• viewport: Viewport

The Viewport to render.

• offScreenCanvas: HTMLCanvasElement

The offscreen canvas to render from.

Returns

ImageRenderedEventDetail

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:836

---

_resizeVTKViewports()

abstract protected _resizeVTKViewports(vtkDrivenViewports, keepCamera, immediate): void

Resizes viewports that use VTK.js for rendering. This method must be implemented by subclasses to define their specific resizing strategy.

Parameters

• vtkDrivenViewports: (VolumeViewport | IStackViewport)[]

• keepCamera: boolean

• immediate: boolean

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:777

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_throwIfDestroyed()

protected _throwIfDestroyed(): void

Throws an error if trying to interact with the RenderingEngine instance after its destroy method has been called.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:764

---

addVtkjsDrivenViewport()

abstract protected addVtkjsDrivenViewport(viewportInputEntry, offscreenCanvasProperties?): void

Adds a viewport driven by vtk.js to the RenderingEngine. This method must be implemented by subclasses to define their specific approach to adding VTK.js driven viewports.

Parameters

• viewportInputEntry: InternalViewportInput

Information object used to construct and enable the viewport.

• offscreenCanvasProperties?: unknown

Optional properties for configuring the offscreen canvas.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:803

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destroy()

destroy(): void

destroy the rendering engine. It will remove all the viewports and, if the rendering engine is using the GPU, it will also destroy the GPU resources.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:433

---

disableElement()

disableElement(viewportId): void

Disables the requested viewportId from the rendering engine:

1. It removes the viewport from the the list of viewports
2. remove the renderer from the offScreen render window if using vtk.js driven rendering pipeline
3. resetting the viewport to remove the canvas attributes and canvas data
4. resize the offScreen appropriately (if using vtk.js driven rendering pipeline)

fires Events.ELEMENT_ENABLED

Parameters

• viewportId: string

viewport Id

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:152

---

enableElement()

enableElement(viewportInputEntry): void

Enables the requested viewport and add it to the viewports. It will properly create the Stack viewport or Volume viewport:

1. Checks if the viewport is defined already, if yes, remove it first
2. Checks if the viewport is using a custom rendering pipeline, if no, it calculates a new offscreen canvas with the new requested viewport
3. Adds the viewport

renderingEngine.enableElement({
 viewportId: viewportId,
 type: ViewportType.ORTHOGRAPHIC,
 element,
 defaultOptions: {
   orientation: Enums.OrientationAxis.AXIAL,
   background: [1, 0, 1],
 },
})

fires Events.ELEMENT_ENABLED

Parameters

• viewportInputEntry: PublicViewportInput

viewport specifications

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:95

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enableVTKjsDrivenViewport()

abstract protected enableVTKjsDrivenViewport(viewportInputEntry): void

Enables a viewport to be driven by the offscreen vtk.js rendering engine. This method must be implemented by subclasses to define their specific viewport enabling strategy.

Parameters

• viewportInputEntry: NormalizedViewportInput

Information object used to construct and enable the viewport.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:791

---

fillCanvasWithBackgroundColor()

fillCanvasWithBackgroundColor(canvas, backgroundColor): void

Fill the canvas with the background color

Parameters

• canvas: HTMLCanvasElement

The canvas element to draw on.

• backgroundColor: [number, number, number]

An array of three numbers between 0 and 1 that specify the red, green, and blue values of the background color.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:468

---

getOffscreenMultiRenderWindow()

getOffscreenMultiRenderWindow(viewportId?): VtkOffscreenMultiRenderWindow

Returns the offscreen multi-render window used for rendering.

Parameters

• viewportId?: string

Returns

VtkOffscreenMultiRenderWindow

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:647

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getRenderer()

getRenderer(viewportId): vtkRenderer

Returns the renderer for a given viewportId.

Parameters

• viewportId: any

The Id of the viewport.

Returns

vtkRenderer

The renderer for the viewport.

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:640

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getStackViewport()

getStackViewport(viewportId): IStackViewport

Retrieves a stack viewport by its ID. used just for type safety

Parameters

• viewportId: string

The ID of the viewport to retrieve.

Returns

IStackViewport

The stack viewport with the specified ID.

Throws

Error if the viewport with the given ID does not exist or is not a StackViewport.

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:335

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getStackViewports()

getStackViewports(): IStackViewport[]

Filters all the available viewports and return the stack viewports

Returns

IStackViewport[]

stack viewports registered on the rendering Engine

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:355

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getViewport()

getViewport(viewportId): Viewport

Returns the viewport by Id

Parameters

• viewportId: string

Returns

Viewport

viewport

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:313

---

getViewports()

getViewports(): Viewport[]

getViewports Returns an array of all Viewports on the RenderingEngine instance.

Returns

Viewport[]

Array of viewports

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:322

---

getVolumeViewports()

getVolumeViewports(): VolumeViewport[]

Return all the viewports that are volume viewports

Returns

VolumeViewport[]

An array of VolumeViewport objects.

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:368

---

render()

render(): void

Renders all viewports on the next animation frame.

fires Events.IMAGE_RENDERED

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:387

---

renderFrameOfReference()

renderFrameOfReference(FrameOfReferenceUID): void

Renders any viewports viewing the given Frame Of Reference.

Parameters

• FrameOfReferenceUID: string

The unique identifier of the Frame Of Reference.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:400

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renderViewport()

renderViewport(viewportId): void

Renders only a specific Viewport on the next animation frame.

Parameters

• viewportId: string

The Id of the viewport.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:424

---

renderViewports()

renderViewports(viewportIds): void

Renders the provided Viewport IDs.

Parameters

• viewportIds: string[]

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:415

---

resize()

resize(immediate, keepCamera): void

Resizes the offscreen viewport and recalculates translations to on screen canvases. It is up to the parent app to call the resize of the on-screen canvas changes. This is left as an app level concern as one might want to debounce the changes, or the like.

Parameters

• immediate: boolean = true

Whether all of the viewports should be rendered immediately.

• keepCamera: boolean = true

Whether to keep the camera for other viewports while resizing the offscreen canvas

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:279

---

setViewports()

setViewports(publicViewportInputEntries): void

It takes an array of viewport input objects including element, viewportId, type and defaultOptions. It will add the viewport to the rendering engine and enables them.

renderingEngine.setViewports([
  {
    viewportId: axialViewportId,
    type: ViewportType.ORTHOGRAPHIC,
    element: document.getElementById('axialDiv'),
    defaultOptions: {
      orientation: Enums.OrientationAxis.AXIAL,
    },
  },
  {
    viewportId: sagittalViewportId,
    type: ViewportType.ORTHOGRAPHIC,
    element: document.getElementById('sagittalDiv'),
    defaultOptions: {
      orientation: Enums.OrientationAxis.SAGITTAL,
    },
  },
  {
    viewportId: customOrientationViewportId,
    type: ViewportType.ORTHOGRAPHIC,
    element: document.getElementById('customOrientationDiv'),
    defaultOptions: {
      orientation: { viewPlaneNormal: [0, 0, 1], viewUp: [0, 1, 0] },
    },
  },
])

fires Events.ELEMENT_ENABLED

Parameters

• publicViewportInputEntries: PublicViewportInput[]

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:236

---

setVtkjsDrivenViewports()

abstract protected setVtkjsDrivenViewports(viewportInputEntries): void

Sets multiple vtk.js driven viewports to the RenderingEngine. This method must be implemented by subclasses to define their specific approach to setting multiple VTK.js driven viewports.

Parameters

• viewportInputEntries: NormalizedViewportInput[]

An array of information objects used to construct and enable the viewports.

Returns

void

Defined in

packages/core/src/RenderingEngine/BaseRenderingEngine.ts:824