SetBuffer for AOS and SOA Data Array Templates

vtkAOSDataArrayTemplate and vtkSOADataArrayTemplate now provide a SetBuffer() method that accepts a vtkBuffer (or vtkAbstractBuffer in Python) to replace the array’s internal storage. This enables zero-copy buffer transfers between arrays without going through raw pointers.

AOS Arrays

vtkNew<vtkBuffer<double>> buffer;
buffer->Allocate(100);
// ... fill buffer ...

vtkNew<vtkDoubleArray> arr;
arr->SetNumberOfComponents(3);
arr->SetBuffer(buffer, true); // true = update MaxId from buffer size

SOA Arrays

For SOA arrays, SetBuffer() takes a component index since each component is stored separately:

vtkNew<vtkBuffer<double>> buf0;
buf0->Allocate(100);

vtkNew<vtkSOADataArrayTemplate<double>> arr;
arr->SetNumberOfComponents(2);
arr->SetBuffer(0, buf0, true);  // set buffer for component 0
arr->SetBuffer(1, buf1, false); // set buffer for component 1

Python

SetBuffer() is fully wrapped for Python using vtkAbstractBuffer:

src = vtkFloatArray()
src.SetNumberOfTuples(100)

dst = vtkFloatArray()
dst.SetNumberOfComponents(1)
dst.SetBuffer(src.GetBuffer(), True)

BufferChangedEvent

SetBuffer(), SetArray(), and ShallowCopy() now fire BufferChangedEvent on both AOS and SOA array templates, matching the existing behavior of Resize() and InsertNextTuple(). This ensures that external consumers (such as NumPy views) are notified whenever the underlying buffer changes.