Class Expression

Expression class manages the rendering pipeline by defining the order and sequence of render passes. It acts as a container that orchestrates multiple render passes to create complex rendering effects.

Example

const expression = new Expression();
expression.addRenderPasses([shadowPass, mainPass, postProcessPass]);

Hierarchy (view full)

Constructors

constructor

Properties

_tags InvalidObjectUID currentMaxObjectCount

Accessors

objectUID renderPasses uniqueName

Methods

_copyFrom addRenderPasses clearRenderPasses clone getTag getTagValue hasTag matchTag matchTags matchTagsAsFreeStrings removeTag setViewport tryToSetTag tryToSetUniqueName unregister validateTagString _reset getRnObject getRnObjectByName searchByTag

Constructors

constructor

Properties

_tags

_tags: RnTags = {}

Collection of tags associated with this object

Static ReadonlyInvalidObjectUID

InvalidObjectUID: -1 = -1

Invalid object UID constant

StaticcurrentMaxObjectCount

currentMaxObjectCount: number = 0

Current maximum object count for UID generation

Accessors

objectUID

  • get objectUID(): number

  • Gets the unique object identifier

    Returns number

    The object's UID

renderPasses

  • get renderPasses(): RenderPass[]

  • Gets a read-only reference to the array of render passes in this expression. The render passes are returned in the order they will be executed.

    Returns RenderPass[]

    Array of RenderPass instances in execution order

uniqueName

  • get uniqueName(): string

  • Gets the unique name of this object

    Returns string

    The unique name string

Methods

_copyFrom

addRenderPasses

  • addRenderPasses(renderPasses): void

  • Appends multiple render passes to the end of the current render pass sequence. The order of render passes determines the rendering pipeline execution order.

    Parameters

    • renderPasses: RenderPass[]

      Array of RenderPass instances to be added

    Returns void

clearRenderPasses

  • clearRenderPasses(): void

  • Removes all render passes from this expression. This effectively resets the expression to an empty state.

    Returns void

clone

getTag

  • getTag(tagName): Tag

  • Retrieves a complete tag object (name and value) for the specified tag name

    Parameters

    • tagName: string

      The name of the tag to retrieve

    Returns Tag

    A Tag object containing the name and value

getTagValue

  • getTagValue(tagName): any

  • Retrieves the value associated with a specific tag name

    Parameters

    • tagName: string

      The name of the tag whose value to retrieve

    Returns any

    The tag value, or undefined if the tag doesn't exist

hasTag

  • hasTag(tagName): boolean

  • Checks whether this object has a tag with the specified name

    Parameters

    • tagName: string

      The name of the tag to check for

    Returns boolean

    True if the tag exists (value is not null/undefined), false otherwise

matchTag

  • matchTag(tagName, tagValue): boolean

  • Checks if this object has a tag with the specified name and value

    Parameters

    • tagName: string

      The tag name to match

    • tagValue: string

      The tag value to match

    Returns boolean

    True if the object has a matching tag, false otherwise

matchTags

  • matchTags(tags): boolean

  • Checks if this object has all the specified tags with exactly matching values

    Parameters

    • tags: RnTags

      Object containing tag names as keys and expected values

    Returns boolean

    True if all specified tags exist with matching values, false otherwise

matchTagsAsFreeStrings

  • matchTagsAsFreeStrings(stringArray): boolean

  • Checks if the object's combined tag string contains all the provided search strings. This allows for flexible searching within tag names and values.

    Parameters

    • stringArray: string[]

      Array of strings that must all be present in the combined tag string

    Returns boolean

    True if all strings are found in the combined tag string, false otherwise

removeTag

setViewport

  • setViewport(viewport): void

  • Sets the viewport dimensions for all render passes in this expression. This is a convenience method to apply the same viewport to all passes at once.

    Parameters

    • viewport: IVector4

      Vector4 containing viewport coordinates (x, y, width, height)

    Returns void

tryToSetTag

  • tryToSetTag(tag): boolean

  • Attempts to set a tag on this object. If the tag already exists, it will be replaced.

    Parameters

    • tag: Tag

      The tag object containing the name and value to set

    Returns boolean

    True if the tag was successfully set, false if the tag name contains invalid characters

tryToSetUniqueName

  • tryToSetUniqueName(name, toAddNameIfConflict): boolean

  • Attempts to set a unique name for this object

    Parameters

    • name: string

      The desired unique name

    • toAddNameIfConflict: boolean

      If true, appends UID to make name unique when conflicts occur; if false, fails on conflict

    Returns boolean

    True if the name was successfully set, false if there was a conflict and toAddNameIfConflict was false

unregister

validateTagString

  • validateTagString(val): boolean

  • Validates that a tag string contains only allowed characters (alphanumeric and underscore)

    Parameters

    • val: string

      The string to validate

    Returns boolean

    True if the string contains only valid characters, false if it contains invalid characters

Static_reset

StaticgetRnObject

  • getRnObject(objectUid): undefined | RnObject

  • Retrieves an RnObject instance by its unique identifier

    Parameters

    • objectUid: number

      The unique identifier of the object to retrieve

    Returns undefined | RnObject

    The RnObject instance or undefined if not found or garbage collected

StaticgetRnObjectByName

StaticsearchByTag

  • searchByTag(tag, value): undefined | WeakRef<RnObject>

  • Searches for the first object that has a specific tag with the given value

    Parameters

    • tag: string

      The tag name to search for

    • value: string

      The tag value to match

    Returns undefined | WeakRef<RnObject>

    WeakRef to the first matching object, or undefined if not found

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