Switching draw modes mid-shape, without the crash

You start a rectangle. Halfway through, you realize it should be a polygon. You switch tools and click. The app crashes.

That sequence, three clicks with no warning, has been crashing LabelMe since v6.0. v6.3.1 fixes it.

How it works#

Mid-shape mode switches stop crashing. Beyond that, they actually start doing something useful.

If you switch between rectangle, polygon, oriented rectangle, circle, line, or linestrip while drawing, your first click stays put. The half-drawn shape changes type under you. Rectangle-then-polygon becomes a fluid swap; you don't have to start over.

If you switch to point, AI Points, or AI Box, the partial gets dropped and you start fresh. Those tools need different inputs, so there's nothing to carry over.

Two other cleanups#

Empty shapes stay out of your annotation files. You can accidentally produce an empty shape by double-clicking too fast. v6.3.1 catches the common cases (zero-area rectangles, zero-length lines, single-point polygons) and drops them before they reach disk.

Edit mode waits for the shape to finish. If you're mid-shape, LabelMe blocks the switch into edit mode until you finish or press Escape. Keeps your half-drawn work from getting accidentally clobbered.

The shape of this change#

The fix is small. You'll mostly notice it as the absence of a crash.

The deeper shift is that LabelMe stopped treating "change your mind mid-drawing" as an error. Annotators change their mind. Rectangle becomes polygon becomes oriented rectangle. The canvas follows.

Where to find it#

Update to LabelMe v6.3.1 from the download page. Both fixes are automatic; nothing to enable.

If you want the engineering story, the v6.3.1 release notes on GitHub link to the pull requests with the full technical detail.

If you hit a draw-mode situation that still misbehaves, open a GitHub issue or ask on Discord.