https://bugs.winehq.org/show_bug.cgi?id=33610
--- Comment #12 from JKAbrams j@jkabrams.se --- Ok, so I had some time to retest this.
My experience: Start Photoshop CS6 with graphics acceleration enabled. Open a photo (20Mp). I see the accelerated gradual zooming effect (but it is very sluggish).
(1) Create new layer, Select all (ctrl + a), Cut photo image (ctrl + x), switch to new layer, paste image (ctrl + v). Result: Photoshop shows a white area where the photo is supposed to have been pasted in main drawing window. Preview shows the photo correct.
Disable effects in Preference > Performance > [ ] Use graphics processor. Quite Photoshop, restart.
Retry (1). Result: Photoshop shows the image with no delay.
Enable effects in Preference > Performance > [X] Use graphics processor.
Retry (1) again. Result: Photoshop shows the image with no delay (scrolling test, see below). No acceleration is done when zooming.
After repeating a few times I found that the redrawing is not always "all or nothing", sometimes the areas that does not get drawn properly does not represent one "rendering-step", but parts of the photo are drawn while others are left white. Also triggering a redraw in other ways than painting something (like switching windows with alt + tab) makes the image paint itself properly. While scrolling the image is alway one step behind, it is quite easily spotted when switching direction in the scrolling, the image will continue one step to the left when the scrollbar is being switched to start pulling right. Preview is always drawn correctly.
I found a related but different problem while using the brush tool in unaccelerated mode. I set the tool size to about 125 with half hardness, and single-click on different locations on the image to create distinct single half-transparent dots. After doing a few of these I notice odd things happening, Photoshop seems to loose the mouse-position. Sometimes nothing gets painted on the new position, the dot is instead created on the location of a previous click. And sometimes it doesn't register that the mouse button has been released and instead paints a straight line onto the place where the next dot is supposed to be painted. In summary: The brush tool is quite unusable, but I think this is unrelated to the redraw issue.
Hope this clears up the confusion.