glXChooseVisual does not handle GLX_RGBA correctly

[Geoff Levner]

I have an OpenGL-based application executing on a Sun, but displaying on 
a PC running Windows XP and an X server. The app requires a TrueColor 
visual, so when it calls glXChooseVisual, it passes GLX_RGBA in the 
attribute list. This works fine with another X server (Exceed), but when 
using Cygwin/X, glXChooseVisual fails to return a visual.

Running xdpyinfo would seem to indicate that the server has *only* 
TrueColor visuals (see the output below). And in fact if I remove 
GLX_RGBA from the attribute list, glXChooseVisual does return one of 
those visuals. If I ask for information about the visual with 
glXGetConfig, it responds that color buffers store color indices 
(GLX_RGBA is false), yet the application works correctly.

Anybody have a clue what is going on here?

Thanks,
Geoff

Output from xdpyinfo:

  number of visuals:    4
  default visual id:  0x22
  visual:
    visual id:    0x22
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits
  visual:
    visual id:    0x23
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits
  visual:
    visual id:    0x24
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits
  visual:
    visual id:    0x25
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://x.cygwin.com/docs/
FAQ:                   http://x.cygwin.com/docs/faq/