Scrolling a very big image list is laggy

[ngyikp]

I optimised an assets folder with about ~3600 images, and scrolling the list is very laggy even after the optimisation is done.

Video: https://dl.dropboxusercontent.com/u/1286251/images/imageoptim%20lag.mp4

ImageOptim version 1.6.1
Mac OS 10.11.4

[kornelski]

Yes, I can confirm this. There's some awful performance regression in OS X that makes drawing of images in the list incredibly slow. System spends 99% of time in the argb32_image_mark_argb32 function, burning cycles.

I'm not sure what to do about it from ImageOptim's perspective, because I'm only using very high-level concepts like imageNamed and image table cell.

[MiroHofo]

Could something be done about this?
UI is very very laggy, it is pain to use it, sort it, scroll. There has to be a way how to optimize it, please :)

[MiroHofo]

Hey guys!
I have found what is causing issue and got a fix. It was all caused by opacity at loupe button, so whan I removed it, scrolling, sorting, selecting items is fast as lightning. Modified code in RevealButtonCell.m (if switch can be removed completely):
float opacity = iMouseHoveredInInfoButton ? 1.0f : ([self isHighlighted] ? 1.0f : 1.0f); [image drawInRect:infoButtonRect fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:opacity respectFlipped:YES hints:nil]; }
First time using Xcode and git and don't know how to submit this. @pornel could you please submit this fix and build new version?

RevealButtonCell.m.zip

[kornelski]

Oh, brilliant! I wrongly assumed that image rendering was from the status image column, and didn't think of the loupe.

Hopefully fixed in 6ee2893