Menu

FSAA (multisample) on Apple OS X with GLX

Using GLFW
2012-02-28
2012-11-08
  • Steven Queen

    Steven Queen - 2012-02-28

    Hi,

    I am hoping someone here might be able to help me with an issue I have been
    struggling with using GLX/X11 on Apple's OS X (Snow Leopard). I have an
    application that we use on both Linux and Mac that tries to open a glxFBConfig
    with multi-sample support (Full Scene Anti-Aliasing). The code works great
    on Linux, and even seems to work fine on OS X--both report a context with the
    correct number of multi-samples--but on OS X, the scene is still not anti-
    aliased.

    Would one of the GLFW developers mind telling me is they are able to get FSAA
    working (via GLX) on OS X or is it a lost cause?

    The other slightly odd OS X wrinkle can be seen directly from a dump of
    glxinfo. The first set of configs it lists are label "GLX Visuals" and
    none show number multisamples greater than zero. But, in the bottom half of
    outputs labeled "GLXFBConfigs" (i.e. the GLX 1.3+ method?) there are a
    multiplicity of multisample configs. Programmatically, the result of
    glXChooseFBConfig yields configs that each have an associated visual
    (GLX_VISUAL_ID). I would expect the two to match like they do under Linux.

    The web is oddly silent on this topic. Since GLFW is a cross-platform project
    I thought perhaps you folks may have bumped into (and hopefully) solved this
    puzzle.

    Thanks in advance for any help you may be able to provide.

    -squeen

     
  • Steven Queen

    Steven Queen - 2012-02-29

    I received some good news. Apparently OS X 10.7 (Lion) has upgraded the GLX
    server version from 1.2 to 1.4 and now supports visuals with multi-sample. The
    odd mismatch between glxFBConfigs and visuals was some sort of partial
    implementation kludge and FSAA appears to have been straightened out in the
    new X11 for OS X.

     
  • elmindreda

    elmindreda - 2012-02-29

    Thank you for posting the follow-up. It's good to know that the GLX
    implementation of X11.app has been fixed.