Paintstormstudio.com

For now only way to quickly mirror brush - for example to paint non symmetrical brush from different angle - is by using "Angle 2" and setting it up to 180.
First problem with this is that you have to carefully setup 180 degrees so it's not rapid fast.
Second problem is that brush preview outline is updated to correct angle only when you make a stroke and shows incorrect angle when hovering over canvas.

It would be nice to have horizontal and vertical mirrors and maybe even 90 degrees rotations as hotkeys.

This kind of feature will be especially useful with flat brushes that use gradated edge for building forms of a painted objects.

but you can swap horizontal and vertical brush form at the brush form center editor

Yes I know. Maybe I didn't explained well enough what i want to achieve.

When I use knife like brush with falloff (sharp on one edge gradually going to full alpha on the other) I want center of the brush on the sharp edge all the time.
When I paint I want to, with hotkey, rotate my brush 180 deegrees (currently I use rotation) so I will have falloff side of the brush in direction that I need for the moment.

Opening this dialog and changing constantly form mirror and center point is not fast enough.

Brush angle hotkey (something like for size) would also help.
I also have problem with brush preview if you set Angle2 to 180 brush preview when you hover is in wrong angle but it updates when stroke is made.