Hello,
I have recently recompiled my application with xforms v0.89.0, previously
v0.88.1. The way OpenGL canvases are handled seems to have changed:
whereas before a window could be moved across the canvas without causing
the canvas to flicker, the same program now exhibits severe flickering,
sometimes even displaying a black screen instead of the canvas contents.
This is only the case if the top window overlaps both the glcanvas and the
bottom window of which the canvas is a part. When the top window overlaps
only the canvas (i.e., when the canvas is large enough), there is no
flickering.
This appears not to be a single/double buffer issue: querying the glcanvas
defaults with fl_get_glcanvas_defaults() yields the default canvas
attributes as specified in the manual:
GLX_RGBA,GLX_DEPTH_SIZE,1,GLX_RED_SIZE,1,GLX_GREEN_SIZE,1,GLX_BLUE_SIZE,1,
GLX_DOUBLEBUFFER (so it is a doublebuffered canvas)
The glwin.c demo program does not exhibit this behaviour.
Question: have the glcanvas class initialization or activation routines
(as set by fl_modify_canvas_prop()) been changed from v0.88.1 to v0.89.0?
Or is this possibly a colormap issue? The manual says that "it is a good
idea to fill [the canvas colormap] with xforms's default colors to reduce
flashing."
Thanks for your help, Daniel
Daniel Weiss tel: +49 551 399431
Institute for X-Ray Physics (IRP) fax: +49 551 399430
University Georgia Augusta at Goettingen email: Daniel.Weiss@
Geiststrasse 11, 37073 Goettingen, Germany phys.uni-goettingen.de
PGP public key:
http://wwwkeys.pgp.net:11371/pks/lookup?op=index&search=0x3D3E57B9&fingerprint=on
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