Local undo makes the most sense here. Global undo/restore will be left to history tracking.
Each operation has an inverse pushed onto the undo stack. Undo operations push redo operation onto stack.
Draw undo: Objects.delete stroke. Store stroke in redo operation.
Erase undo: store stroke in undo operation. Redo: erase. This won't get the stacking order right until we implement stack re-ordering, but I think it's better than marked items deleted?
Local undo makes the most sense here. Global undo/restore will be left to history tracking.
Each operation has an inverse pushed onto the undo stack. Undo operations push redo operation onto stack.
Objects.deletestroke. Store stroke in redo operation.deleted?