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BufferTransform

BufferTransform is the engine wrapper for WebGL transform-feedback workflows. It internally builds a Model plus a TransformFeedback object and uses them to run buffer-to-buffer transforms.

BufferTransform is only supported on WebGL devices.

Usage​

import {BufferTransform} from '@luma.gl/engine';

const transform = new BufferTransform(device, {
  vs: VERTEX_SHADER,
  outputs: ['outValue'],
  attributes: {
    inValue: sourceBuffer
  }
});

transform.run({
  outputBuffers: {
    outValue: targetBuffer
  }
});

Types​

BufferTransformProps​

export type BufferTransformProps = Omit<ModelProps, 'fs'> & {
  fs?: ModelProps['fs'];
  outputs?: string[];
  feedbackBuffers?: Record<string, Buffer | BufferRange>;
};

feedbackBuffers is deprecated in favor of run({outputBuffers}).

Properties​

device​

Owning device.

model​

Internal model used to run the transform-feedback draw.

transformFeedback​

Internal transform-feedback object.

Methods​

BufferTransform.isSupported(device: Device): boolean​

Returns true when the device is WebGL-backed.

constructor(device: Device, props?: BufferTransformProps)​

Creates the internal model and transform-feedback objects. Throws on unsupported devices.

destroy(): void​

Destroys the internal model.

delete(): void​

Deprecated alias for destroy().

run(options?): void​

Runs one transform-feedback pass.

run(options?: RenderPassProps & {
  inputBuffers?: Record<string, Buffer>;
  outputBuffers?: Record<string, Buffer>;
}): void

getBuffer(varyingName: string): Buffer | BufferRange | null​

Deprecated accessor for one named transform-feedback output.

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

Deprecated helper for reading back one named output.

Remarks​

  • BufferTransform defaults the fragment shader to a passthrough implementation because transform feedback typically only needs vertex output.
  • Prefer run({inputBuffers, outputBuffers}) for explicit buffer management.