Class PrimitiveMeshIndexTexture

GPU data texture mapping each primitive to its owning mesh for a given render pass.

PrimitiveMeshIndexTexture is a GPU-resident table used by the renderer to efficiently determine, for each primitive (triangle, line, or point), which mesh it belongs to and its offset within that mesh.

Structure

  • Each item stores two uint32 values: meshIndex and offset.
  • Items are grouped into "portions", each associated with a mesh and a render pass (e.g., OPAQUE, XRAYED).
  • The texture maintains a mapping of render pass IDs to primitive ranges, enabling fast per-pass rendering.

Hierarchy (View Summary)

Properties

buffer bufferClass bytesPerTexel debugging description elementsPerItem elementsPerTexel format gl height internalFormat itemSizeInBytes lastUploadTimeMS maxItems onUpdated passRanges texelsPerItem texture type width itemSizeInBytes

Accessors

numItems numPrimitives

Methods

allocate cancelUploads canGetPortion createPortion deletePortion destroy getAllocatedBytes getItem getPassRange getUsedBytes isVisible notifyUpdated setMeshVisible setObjectVisible setRenderPass uploadChanges webglContextRestored decodeAddress encodeAddress

Properties

buffer

buffer: any

CPU-side backing buffer used to populate this texture.

The concrete type depends on the implementation (e.g., Uint32Array, Float32Array, or a view over an ArrayBuffer). This buffer is uploaded to the GPU when updated.

bufferClass

bufferClass: any

The ArrayBufferView class used for the CPU-side buffer.

bytesPerTexel

bytesPerTexel: number

Size in bytes of a single texel in the data texture.

debugging

debugging: boolean = true

Enables internal event emission for this data texture.

description

description: string = ""

Human-readable description of the data stored in this texture.

Intended for debugging UIs and diagnostics (e.g., displayed above inspectors). Subclasses or owners should populate this with a concise explanation of the layout and semantic meaning (e.g., “mesh matrices (Mat4, row-major), indexed by meshId”).

elementsPerItem

elementsPerItem: number

Number of individual elements (e.g., floats, uint32s) stored per logical item in this data texture.

elementsPerTexel

elementsPerTexel: number

Number of individual elements (e.g., floats, uint32s) stored per texel in the data texture.

format

format: number

Texture format (e.g., gl.RGBA, gl.RGBA_INTEGER).

gl

gl: WebGL2RenderingContext

The WebGL2 rendering context.

height

height: number

Texture height in texels.

internalFormat

internalFormat: number

Texture internal format (e.g., gl.RGBA8, gl.RGBA32UI, gl.RGBA32F).

itemSizeInBytes

itemSizeInBytes: number

Size in bytes of a single logical item stored in the data texture.

lastUploadTimeMS

lastUploadTimeMS: number = 0

Duration (in milliseconds) of the last upload to GPU.

This value is 0 until the first upload occurs.

maxItems

maxItems: number

Maximum number of logical items that can be stored in this texture.

The value of numItems never exceeds this limit.

onUpdated

onUpdated: EventEmitter<DataTexture, undefined> = ...

Emitted when the CPU-side buffer for this texture has changed and been uploaded to the GPU.

This event is intended for debugging tools and monitoring UIs; it is only emitted when debugging is enabled.

ReadonlypassRanges

passRanges: Map<number, PrimRange> = ...

texelsPerItem

texelsPerItem: number

Number of texels occupied by a single logical item in the data texture.

Internaltexture

texture: WebGLTexture

The underlying WebGL texture object.

This is the GPU resource that is bound and sampled/loaded by shaders.

type

type: number

Texture data type (e.g., gl.UNSIGNED_BYTE, gl.UNSIGNED_INT, gl.FLOAT).

width

width: number

Texture width in texels.

Static ReadonlyitemSizeInBytes

itemSizeInBytes: 8

Accessors

numItems

numPrimitives

Methods

allocate

ProtectedcancelUploads

canGetPortion

createPortion

deletePortion

destroy

getAllocatedBytes

getItem

  • getItem(primIndex: number): { meshIndex: number; offset: number }

    Gets the meshIndex and offset for a primitive index.

    The offset is the index of the primitive within its mesh. For example, for a triangle mesh, the offset will be 0 for the first triangle, 1 for the second triangle, and so on. This allows the vertex shader to determine which vertices to use when rendering the primitive.

    Parameters

    • primIndex: number

      Primitive index.

    Returns { meshIndex: number; offset: number }

getPassRange

getUsedBytes

isVisible

ProtectednotifyUpdated

setMeshVisible

setObjectVisible

setRenderPass

uploadChanges

  • uploadChanges(): boolean

    Uploads current CPU buffer if dirty; rebuilds runs when necessary.

    Internal algorithm:

    • If no upload is needed, returns false.
    • If no items are allocated, clears buffer and returns false.
    • Otherwise, rebuilds runs and buffer:
      • Groups portions by renderPass, preserving insertion order.
      • Packs contiguous runs per renderPass, updating offsets.
      • Updates passRanges for each renderPass.
      • Uploads buffer to GPU.
      • Updates numDrawablePrims.
    • Notifies update and resets needUpload.

    Returns boolean

    True if any uploads occurred, false otherwise.

webglContextRestored

StaticdecodeAddress

StaticencodeAddress

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