Nim,

I currently have both Open GL with High Quality Filtering and Instant Preview Mode activated. Here's what I've notice when testing brushes scales to 200+ pixels:

• Most brushes that scale based on pressure, seem to work perfectly fine
• Brush that rotate, jitter, etc behave much like Corel Painter brushes when they're scaled too large or are too processor intensive, they visual work in slow motion.
• Most brushes that varies in opacity based on pressure seem sluggish.

If anyone wants to look at my terminal output, please let me know. It's looks like too much to justify posting on a forum. Also I don't see an option to attach it as a text file.

Well, that sounds kind of normal, actually

Nim and Boud - here's a snapshot of what I was talking about on #krita regarding my Instant Preview brush settings.

BTW, Nim I think you're off the hook, cause I just tested with the latest master (forcing Core 2.1 of course) and the app behaves the same.
Just thought I'd give you an update here, there may be some related issues with your branch



From the look of it, there's nothing wrong cause it's a legitimate case where Instant Preview and Filter Gaussian Blur don't mix (I guess)

But the UX is a tad quirky (imho)... Here's my use case:

- Cleared all my settings in Application Support/krita
- Opened a New Document
- Freehand Brush Tool (think it comes up as default)
- Invoke the Brush Settings from the toolbar
- All brush settings start out with Instant Preview checked. Whether the Instant Preview Mode is enabled or not. Also whether your GL can handle it or not ...
- If the Filter Engine is selected the Instant Preview check box goes dark (as shown above). Turns out the default is Gaussian Blur.
- Hint reports that Gaussian Blur and Instant Preview don't mix ... so far so good...makes sense
- But the settings dialog/panel remains "stuck" in this mode no matter what brush engine is selected afterwards
- The only way to reset it, so to speak, is to select a non-Filter brush engine and tickle a setting

So a combination of UI, UX issues. Not sure if more code/logic is also implicated (haven't tested that far).
Do you guys think I have a legitimate issue? If so, I'll file a bug promptly.

Just my experience trying to test Instant Preview in all its modes (there are many). Otherwise, great work Nim! Can't wait for this to migrate to master

I'll pull your branch down and build locally - dreading the qt 5.7 rebuild and patching (ughhhh...)

Regards, Patrice

Test Environment
krita nimmy2.dmg
mac pro 3,1
NVIDIA GeForce GTX 680 2G
Sierra GM
Xcode 8 Release

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