Skip to main content

BufferTransform

WebGPU not supported

BufferTransform manages resources and state required for doing TransformFeedback based GPU computations reading from and/or writing to Buffer objects.

Types​

BufferTransformProps​

export type BufferTransformProps = Omit<ModelProps, 'fs'> & {
  fs?: ModelProps['fs']; // override as optional
  feedbackBuffers?: Record<string, Buffer | BufferRange>;
};
  • props.feedbackBuffers (Object, Optional) - Map of output buffers that the shaders will write to. Key and value pairs, where key is the name of vertex shader varying and value is the corresponding Buffer object or buffer params object. If a buffer params object is specified, it will contain following fields, these can be used to capture data into the buffer at particular offset and size.
    • buffer=(Buffer) - Buffer object to be bound.
    • byteOffset=(Number, default: 0) - Byte offset that is used to start recording the data in the buffer.
    • byteSize=(Number, default: remaining buffer size) - Size in bytes that is used for recording the data.

Methods​

constructor​

new BufferTransform(device: Device, props: BufferTransformProps)
  • device (Device) - device
  • props.feedbackBuffers - Map of output buffers that the shaders will write to. Key and value pairs, where key is the name of vertex shader varying and value is the corresponding Buffer object or buffer params object. If a buffer params object is specified, it will contain following fields, these can be used to capture data into the buffer at particular offset and size.
    • buffer=(Buffer) - Buffer object to be bound.
    • byteOffset=(Number, default: 0) - Byte offset that is used to start recording the data in the buffer.
    • byteSize=(Number, default: remaining buffer size) - Size in bytes that is used for recording the data.
  • props.sourceBuffers (Object, Optional) - key and value pairs, where key is the name of vertex shader attribute and value is the corresponding Attribute, Buffer or attribute descriptor object.
  • props.varyings (Array, Optional) - Array of vertex shader varyings names. When not provided this can be deduced from feedbackBuffers.

run(props: RenderPassProps)​

Updates buffer bindings for one or more source or feedback buffers.

  • props (Object) - contains following data.
    • sourceBuffers (Object, Optional) - key and value pairs, where key is the name of vertex shader attribute and value is the corresponding Attribute, Buffer or attribute descriptor object.
    • feedbackBuffers (Object, Optional) - key and value pairs, where key is the name of vertex shader varying and value is the corresponding Buffer object or buffer params object. If a buffer params object is specified, it will contain following fields, these can be used to capture data into the buffer at particular offset and size.
      • buffer=(Buffer) - Buffer object to be bound.
      • byteOffset=(Number, default: 0) - Byte offset that is used to start recording the data in the buffer.
      • byteSize=(Number, default: remaining buffer size) - Size in bytes that is used for recording the data.

getBuffer(varyingName : String) : Buffer​

Returns current feedback buffer corresponding to given varying name.

  • varyingName (String) - varying name.

readAsync(varyingName: string) : Promise<Uint8Array>​

Reads and returns data from current feedback buffer corresponding to the given varying name.

  • varyingName - when specified, first checks if there is a corresponding feedback buffer, if so reads data from this buffer and returns. When not specified, there must be target texture and data is read from this texture and returned.