overwriteGeometry method

  1. @override
void overwriteGeometry(
  1. GeometryBuffer target,
  2. int offsetInBytes,
  3. ByteData bytes
)

Writes bytes into target starting offsetInBytes into it, in place.

Visible starting the next pass, never the one already encoded. None of the four backends here promise anything about a draw already recorded against the old bytes — WebGL2's bufferSubData, WebGPU's queue.writeBuffer and flutter_gpu's DeviceBuffer.overwrite are all queued relative to submission, not to the moment this call returns, so a pass encoded and submitted before this call still draws what it was given. A caller that needs the new bytes in the frame being built has to call this before recording the draw, not after.

offsetInBytes and bytes.lengthInBytes must together fit inside target — offsetInBytes + bytes.lengthInBytes <= target.lengthInBytes — checked here rather than left to a backend, because a backend that caught it would report three different exceptions for one mistake.

target must be a buffer this device itself returned from uploadGeometry, not a slice of unrelated bytes — the same requirement releaseGeometry already carries.

Implementation

@override
void overwriteGeometry(
  GeometryBuffer target,
  int offsetInBytes,
  ByteData bytes,
) => guard(
  'a ${bytes.lengthInBytes}-byte overwrite at $offsetInBytes',
  () => webgpuOverwriteGeometry(gpuDevice, target, offsetInBytes, bytes),
);