Part of the Khronos Group
OpenGL.org

The Industry's Foundation for High Performance Graphics

from games to virtual reality, mobile phones to supercomputers

Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: ATI: no hardware support for gl_FragCoord ??

  1. #1
    Junior Member Regular Contributor
    Join Date
    Jan 2002
    Location
    France
    Posts
    129

    ATI: no hardware support for gl_FragCoord ??

    When I use gl_FragCoord (.x, .z or whatever) in a fragment program, it automatically switch to software renderer... Does it means there's no support currently for this basic built-in variable ?? That's very annoying when you need depth to compute your pixel...

    (I'm using Radeon 9800SE with catalyst 4.3)

  2. #2
    Junior Member Regular Contributor
    Join Date
    Jan 2002
    Location
    France
    Posts
    129

    Re: ATI: no hardware support for gl_FragCoord ??

    ok I found a nice workaround. If you have this problem too and want to deal with it mail me.

  3. #3
    Advanced Member Frequent Contributor
    Join Date
    Oct 2001
    Posts
    596

    Re: ATI: no hardware support for gl_FragCoord ??

    gl_FragCoords works for me.. so maybe its in conjunction with some other part of your programs?

  4. #4
    Junior Member Regular Contributor
    Join Date
    Jan 2002
    Location
    France
    Posts
    129

    Re: ATI: no hardware support for gl_FragCoord ??

    what's your hardware/driver release ?

  5. #5
    Junior Member Regular Contributor
    Join Date
    May 2003
    Location
    Germany
    Posts
    229

    Re: ATI: no hardware support for gl_FragCoord ??

    I also have no problem with that constant, and I'm using ATI's GLSL-implementation since the CoD-Hotfix-Catalyst (I think it was Cat3.9+) on a Radeon9700.
    So I'm quite sure that your problem emerges from somewhere else. Maybe you assigned something to glFragCoord.* that caused the driver to switch to SW-mode. (Like glFragCoord.x = Noise(), where the noise-command will force the whole shader into SW-mode).

  6. #6
    Advanced Member Frequent Contributor
    Join Date
    Oct 2001
    Posts
    596

    Re: ATI: no hardware support for gl_FragCoord ??

    Originally posted by divide:
    what's your hardware/driver release ?
    9800Pro catalyst 3.4

  7. #7

    Re: ATI: no hardware support for gl_FragCoord ??

    There is something wrong with gl_FragCoord and there are some strange side effects. The returned value is correct and the shader runs in hw, but the interpolation of varyings seems to be corrupted even in other shader objects. I've got a similar problem http://www.opengl.org/discussion_boards/cgi_directory/ultimatebb.cgi?ubb=get_t opic;f=11;t=000037 with the Radeon 9800 pro and Catalyst 4.3 .

  8. #8
    Junior Member Regular Contributor
    Join Date
    Jan 2003
    Posts
    113

    Re: ATI: no hardware support for gl_FragCoord ??

    @divide:
    could you post your workaround here? Perhaps this is for more people interesting. With catalyst 4.4 there still seem something broken with gl_FragCoord support.

    When I use gl_FragCoord, the programm compiles and link fine, the drivers says it should run in hardware but rendering is awful slow (as if it run in sw) and the object get rendered with white color.
    This happen in my own program and with the typhoonlabs shader designer.
    Modifying the 3dlabs glsl SDK example it works correct

    Always with the same primitive shader:
    vertex main:
    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;

    fragment main:
    gl_FragColor = gl_FragCoord;

    tested on Radeon 9800 with catalyst 4.4

  9. #9
    Advanced Member Frequent Contributor yooyo's Avatar
    Join Date
    Apr 2003
    Location
    Belgrade, Serbia
    Posts
    872

    Re: ATI: no hardware support for gl_FragCoord ??

    Originally posted by valoh:
    @divide:
    could you post your workaround here? Perhaps this is for more people interesting. With catalyst 4.4 there still seem something broken with gl_FragCoord support.

    When I use gl_FragCoord, the programm compiles and link fine, the drivers says it should run in hardware but rendering is awful slow (as if it run in sw) and the object get rendered with white color.
    This happen in my own program and with the typhoonlabs shader designer.
    Modifying the 3dlabs glsl SDK example it works correct

    Always with the same primitive shader:
    vertex main:
    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;

    fragment main:
    gl_FragColor = gl_FragCoord;

    tested on Radeon 9800 with catalyst 4.4
    I have test it on FX5900 with 60.72 dets and it works in hw. I have to change your FS to gl_FragColor = gl_FragCoord/100.0; and I got nice color gradient. gl_FragCoord contains window coordinates of fragment.

    yooyo

  10. #10
    Junior Member Regular Contributor
    Join Date
    Jan 2003
    Posts
    113

    Re: ATI: no hardware support for gl_FragCoord ??

    Originally posted by yooyo:
    I have test it on FX5900 with 60.72 dets and it works in hw. I have to change your FS to gl_FragColor = gl_FragCoord/100.0; and I got nice color gradient. gl_FragCoord contains window coordinates of fragment.

    yooyo
    yeah, I know. This shader shouldn't do anything usefull, it was only for driver testing.
    And unfortunately there is still a driver bug in catalyst 4.4 regarding gl_FragCoord

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •