Hi,

I'm having an issue with DrawGlyph in 1.2.6 when I'm blitting to a
surface which is fully transparent. Even though the destination alpha is
zero, some of the destination color seeps in during the blit of the
glyph. The blit isn't accelerated, so the code used is all from
generic.c.

For example, if on a graphics layer I draw white text onto a transparent
black surface behind which is a white background layer I would expect to
see nothing but white on the screen. Instead I see a grey outline of the
text where the 'transparent' black has been blended in during the blit.

It may be that the destination alpha isn't being taken into account
during the blit. I've tried merging some blending changes from 1.4.x but
with no change in the net result. Is this a bug in the particular blend
implementation being called, or expected behaviour based on the blitting
flags being used (DSBLIT_BLEND_ALPHACHANNEL | DSBLIT_COLORIZE setup in
fonts.c). Any suggestions about what might be the issue and how to
proceed would be gratefully received.

Hope I've been clear,

Thanks!

Dave.

........................................................................
Dave Craig
Cambridge, UK

_______________________________________________
directfb-users mailing list
[email protected]
http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-users

Reply via email to