I'd do: color = (color & (0x00FFFFFF)) | (alpha << 24);
removes that shift and is a little easier to tell what's happening (I always mix up which right shift does what). Though it probably doesn't matter. :) -Andy On 4/5/07, Oliver Müller <[EMAIL PROTECTED]> wrote:
thanks - thats 10 ms faster each operation. Olli 2007/4/5, Mark Winterhalder <[EMAIL PROTECTED]>: > On 4/5/07, Oliver Müller <[EMAIL PROTECTED]> wrote: > > Hi, > > I want to change the alpha channel of an 32bit integer. > > At the moment I extract every color channel, change the alpha and then > > put them together at the end. > > > > (alpha << 24) | (red << 16) | (green << 8) | blue ) > > > > How can I change the alpha channel directly ? > > You could...: > > color = (color & (-1 >>> 8)) | (alpha << 24); > > ...but I'm not sure if that would be better. > > Mark > _______________________________________________ > [email protected] > To change your subscription options or search the archive: > http://chattyfig.figleaf.com/mailman/listinfo/flashcoders > > Brought to you by Fig Leaf Software > Premier Authorized Adobe Consulting and Training > http://www.figleaf.com > http://training.figleaf.com > _______________________________________________ [email protected] To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
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