This is a bug of the Mac OS X port of Clutter. CGBitmapContextCreate uses premultiplied alpha, while Clutter's COGL expects non-premultiplied alpha. I think there's no bug report for this yet, so feel free to open one.
Thomas On Fri, Dec 26, 2008 at 11:43 PM, Kristjan Vaga <[email protected]> wrote: > Hi, i am making some basic drawing tests with Clutter 0.8.4 to gather > some idea of the capabilities of it. So far everything seems very > good, except one annoying detail that i have not really understood how > to work around: > > I am trying to compose a graphical button with several PNG images laid > on top of each other, having a 8bit alpha channel for transparency. > Problem seems to be that every time the PNG is loaded, it is rendered > on the black canvas, so the semitransparent areas get a darker shade. > Although the transparency itself works as intended. Just the > transparent areas are darker. > > For example, i have an icon with a smooth white glow around it. The > glow is rendered as grey, not white as it looks in photoshop. > > Any ideas, is it something specific to Clutter, or can be worked > around somehow? Or is it just some quirk of my platform - OSX Leopard? > > Kris > -- > To unsubscribe send a mail to [email protected] > > -- To unsubscribe send a mail to [email protected]
