The Rectangle Tool allows you to select a rectangular area of an image.
Selection tools support four different modes:
- "Set" replaces the current selection with a new one.
- "Add" keeps the current select and select new areas in addition to the already selected ones.
- "Sub" deselects already selected image areas.
- "Mul" only selects image areas have already been selected, and deselects areas which are part of the new selection.