PDA

View Full Version : Opacity animation for VGImage



jrabbani
12-01-2010, 08:54 AM
Hi All,

I am trying to animate the opacity of VGImage using VG_COLOR_TRANSFORM. However, I have read on a Qt/Trolltech blog that opacity animation for a VGImage can be achieved via vgColorMatrix(). But that approach has severe performance implications. The blog is:

http://swik.net/Trolltech/Trolltech+Lab ... enVG/df9sz (http://swik.net/Trolltech/Trolltech+Labs+Blogs/Qt+Graphics+and+Performance+OpenVG/df9sz)

My question is: out of the following two approaches, which one is the recommended one to get the desired result?

1 - using vgColorMatrix
2 - using VG_COLOR_TRANSFORM

Thanks.

Regards,
Javed

AlexW
12-23-2010, 10:51 AM
VG_COLOR_TRANSFORM is probably the quickest, vgColorMatrix is a richer operation in terms of its capabilities, but involves an implicit image copy operation.

vgColourMatrix might still be worth considering if you are applying the colour transformation once to an image at the start of your application, but I wouldn't recommend it for runtime use.

Regards,

Alex