HI!
So I do not have time to complete the update in full volume until March 10, I decided to publish something that has already been completed.

This update adds:

Accelerated generator of seamless textures with additional settings.
Square brush (works with color, dodge, burn, stamp)
STAMP brush.
CLONE brush.
Round selection.
Fill the selection.
Choosing shading mode.

To work with the STAMP brush, you need to select (doubleclick) a stamp and choose which channels and layers the stamp will be used on.
Recommended:
Create new layers in each channel and clean up the alpha in each (so only the stamp is used on these layers and channels) like on screenshot below.

At the moment 4 STAMP brushes are available, in the future STAMP library will be replenished. So you can add your own brushes, the main thing is to follow some rules to avoid mistakes.
You will need to create a folder with the name of the brush (example "NEWSTAMP")

In this folder must be located files given the name of this folder:
Example for folder - "NEWSTAMP"
NEWSTAMP.png - This is the icon that will be displayed in the STAMP toolbar.
NEWSTAMP_D.dds
NEWSTAMP_N.dds
NEWSTAMP_S.dds
NEWSTAMP_I.dds
NEWSTAMP_H.dds
NEWSTAMP_G.dds
NEWSTAMP_M.dds
NEWSTAMP_AO.dds

To work with the CLONE brush - on the selected layer, while holding the left ALT key, click the mouse to determine the location from which cloning will occur, then by releasing the ALT key you can clone anywhere in the current layer. The CLONE brush currently only works on the current layer (it is impossible to clone from one layer to another layer), in the future, interlayer cloning will be available. The CLONE brush currently only works with a round brush shape, in the future a square brush will be available.

Fixed unpredictable movement of the viewport camera.

That's all for now.
Feedback is welcome!

Several screenshots from the update.