Cancellation of booleans

[pca006132]

Discussed in https://github.com/elalish/manifold/discussions/957

^{Originally posted by wtholliday September 26, 2024} I would like to add cancellation of boolean operations to the library. Am I correct that no facility currently exists? Progress reporting would be nice as well, though my primary concern is that I'm throwing big enough meshes at Manifold that iOS tends to kill my app for using too much memory. With a cancellation callback I could (hopefully) react to the OS memory warning in time and cancel the operation.

@elalish @pca006132 can you provide guidance? Is the boolean operation done lazily so an optional callback could be passed to Manifold::GetMeshGL()?

thanks!