I proposed this idea to Campbell via email and he said it sounded reasonable enough to add here...
The idea: In the image editor, when the Rendered Result is displayed, pressing F will flip the render horizontally. This is a common action that many digital painters use in Photoshop to refresh their eyes and see new flaws in their work.
- It will should only work in the Rendered Result, not on regular images
- All tools that normally work in Rendered Result, should work here as well. (rendered border, sampling image color, painting)
- Only Flip X. I've tried Flipping Y before, but I haven't found it to be that helpful in the artistic process. Could be added later though if people want it?
- Should apply the Flip state to all Slots. Eg. If flipped in Slot 1, when you change to slot 2 it will also be flipped. If you turn Flip off in Slot 2, it will also be off in Slot 1 and all slots.
- To remove the potential confusion for users who flipped it by accidentally pressing F but don't know the hotkey, a new button should display in the toolbar. Here: