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Old 12-19-2018, 02:17 PM   #13
Justin's Avatar
Join Date: Jan 2005
Location: NYC
Posts: 12,197

Originally Posted by wwwmaze View Post
I really think the issue of the image jumping back is a bug in the video-processor code. If anybody wants to reproduce it, it's much more noticeable if you set video size to something ridiculously low in project settings, like 20x20.
But I can't figure out why it's happening. Removing the "&0xfffe" or "&-2" part (kind of the the same thing) of lines 33 and 34 solves it even though it makes zooming not exactly symmetrical.

The issue of zooming appearing to be stepped could be caused by limitations of gfx_blit (which can take only discrete values) and may be improved by filtering frames over time but it probably reduces the image sharpness.
Try changing the &0xfffe or &-2 to 0xffff or -1, and changing it to use RGB colorspace?

The reason for &-2 / &0xfffe is to make all pixel offsets even, because with YV12/YUY2 and subsampling drawing at odd offsets can do odd things. Maybe those are unnecessary and unhelpful though.
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