I still wonder how kind of google earth rotate image very fast anyway, thank you for your advice~!
2010/10/10 Stephen Bloch <sbl...@adelphi.edu> > On Oct 10, 2010, at 4:17 AM, 김태윤 <kty1...@gmail.com> wrote: > > > there is little images(16x16) that cropped from other chipset > > and I gether them and make an image which size is about 320 x 320 > > > > and I rotate it, but it is very very slow and blink alot > > This is because it really does take a lot of processing to rotate a bitmap > image by an arbitrary angle. I bet it's really fast if you rotate by > exactly 90 degrees.... > > > so I test basic polygon > > it works perfectly, no delay, no blinking, even if when it grows big > > Yes, that's because a polygon is determined by just a few points, so > there's a lot less processing to be done. > > If it makes you feel better, in the old image library the polygon would > have been just as slow as the bitmap :-) > > I don't know enough about the internals of the image library to tell you > how to speed up operations on the former picture. > > Stephen Bloch
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