Incomplete scene with OpenGL + direct rendering + mga

From: Jan Gukelberger (g.u.g.i_at_gmx.de)
Date: 11/24/03

  • Next message: Adam K Kirchhoff: "Re: Incomplete scene with OpenGL + direct rendering + mga" 
    Date: 24 Nov 2003 07:05:38 -0800

    I'm not completely sure this is the right place for this question but
    as I can't figure out on my own if this is a bug in DRI, libgl, the
    mga driver or somewhere else, this list seemed to fit best.

    I have  tried to compile and run some simple OpenGL programs. But lots
    of them don't display anything or only part of the scene if direct
    rendering is enabled.
    However, with LIBGL_ALWAYS_INDIRECT=y the scene looks like it should
    do - but animation is extremely slow.

    My system is a standard SuSE 8.2 installation with XFree86 4.3.0 and
    the standard 2.4.20 kernel.
    Graphics adapter: Matrox Millenium G550 (only first head configured)
    I would have already tried to upgrade some packages if i had known
    where the problem is.

    A program demonstrating this is the following.
    As this is extracted from example source code of the NeHe tutorial
    (nehe.gamedev.net) there shouldn't be any coding mistakes in.
    --- test.c -------------------------------
    #include <GL/glut.h>
    #include <GL/gl.h>
    #include <GL/glu.h>

    void InitGL(int Width, int Height)
    {
      glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
      glClearDepth(1.0);
      glDepthFunc(GL_LESS);
      glEnable(GL_DEPTH_TEST);
      glShadeModel(GL_SMOOTH);
      glViewport(0, 0, Width, Height);
      glMatrixMode(GL_PROJECTION);
      glLoadIdentity();
      gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);
      glMatrixMode(GL_MODELVIEW);
    }

    void DrawGLScene()
    {
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
      glLoadIdentity();

      // Move Left 1.5 Units And Into The Screen 6.0
      glTranslatef(-1.5f,0.0f,-6.0f);

      // draw a triangle
      glColor3f( 1.0f, 1.0f, 1.0f );
      glBegin(GL_POLYGON);
      glVertex3f( 0.0f, 1.0f, 0.0f);
      glVertex3f( 1.0f,-1.0f, 0.0f);
      glVertex3f(-1.0f,-1.0f, 0.0f);
      glEnd();

      // Move Right 3 Units
      glTranslatef(3.0f,0.0f,0.0f);

      // draw another triangle
      glColor3f( 1.0f, 0.0f, 0.0f );
      glBegin(GL_POLYGON);
      glVertex3f( 0.0f, 1.0f, 0.0f);
      glVertex3f( 1.0f,-1.0f, 0.0f);
      glVertex3f(-1.0f,-1.0f, 0.0f);
      glEnd();

      glutSwapBuffers();
    }

    int main(int argc, char **argv)
    {
      glutInit(&argc, argv);
      glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
      glutInitWindowSize(640, 480);
      glutInitWindowPosition(0, 0);
      glutCreateWindow("Window Title");
      glutDisplayFunc(&DrawGLScene);
      glutFullScreen();
      glutIdleFunc(&DrawGLScene);
      InitGL(640, 480);

      glutMainLoop();

      return 0;
    }
    -----------------------------------------

    I compile with
    $ gcc -o test test.c -lglut -lGLU -lGL

    If I run it with
    $ ./test
    I see one white triangle on the left side of the screen.
    If I run with
    $ LIBGL_ALWAYS_INDIRECT=y ./test
    I see a white triangle on the left side and a red triangle on the
    right side.
    There aren't any error messages neither in XFree86.0.log nor on the
    xterm when running the program - even with MESA_DEBUG=y.

    Same result if the OpenGL window is created with GLX or SDL.

    'Real', i.e. more complex OpenGL programs like bzflag run without
    problems.
    Another example demonstrating the problem is the "cube" example
    program that comes with the glut library: With direct rendering
    enabled it does only display a black window.

    --- Output of glxinfo -----------------
    name of display: :0.0
    display: :0 screen: 0
    direct rendering: Yes
    server glx vendor string: SGI
    server glx version string: 1.2
    server glx extensions:
        GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_EXT_import_context
    client glx vendor string: SGI
    client glx version string: 1.2
    client glx extensions:
        GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_EXT_import_context
    GLX extensions:
        GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_EXT_import_context
    OpenGL vendor string: VA Linux Systems Inc.
    OpenGL renderer string: Mesa DRI G400 20020221 AGP 1x x86/MMX/SSE
    OpenGL version string: 1.2 Mesa 4.0.4
    OpenGL extensions:
        GL_ARB_multisample, GL_ARB_multitexture,
    GL_ARB_texture_compression,
        GL_ARB_texture_env_add, GL_ARB_transpose_matrix, GL_EXT_abgr,
        GL_EXT_bgra, GL_EXT_clip_volume_hint,
    GL_EXT_compiled_vertex_array,
        GL_EXT_packed_pixels, GL_EXT_polygon_offset,
    GL_EXT_rescale_normal,
        GL_EXT_texture3D, GL_EXT_texture_env_add, GL_EXT_texture_object,
        GL_EXT_vertex_array, GL_IBM_rasterpos_clip, GL_MESA_window_pos,
        GL_NV_texgen_reflection, GL_SGIS_generate_mipmap
    glu version: 1.3
    glu extensions:
        GLU_EXT_nurbs_tessellator, GLU_EXT_object_space_tess

       visual x bf lv rg d st colorbuffer ax dp st accumbuffer ms cav
     id dep cl sp sz l ci b ro r g b a bf th cl r g b a ns b eat
    ----------------------------------------------------------------------
    0x23 24 tc 1 24 0 r y . 8 8 8 0 0 0 0 0 0 0 0 0 0 None
    0x24 24 tc 1 24 0 r . . 8 8 8 0 0 0 0 0 0 0 0 0 0 None
    0x25 24 tc 1 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None
    0x26 24 tc 1 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None
    0x27 24 tc 1 24 0 r y . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow
    0x28 24 tc 1 24 0 r . . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow
    0x29 24 tc 1 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow
    0x2a 24 tc 1 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow
    0x2b 24 dc 1 24 0 r y . 8 8 8 0 0 0 0 0 0 0 0 0 0 None
    0x2c 24 dc 1 24 0 r . . 8 8 8 0 0 0 0 0 0 0 0 0 0 None
    0x2d 24 dc 1 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None
    0x2e 24 dc 1 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None
    0x2f 24 dc 1 24 0 r y . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow
    0x30 24 dc 1 24 0 r . . 8 8 8 0 0 0 0 16 16 16 0 0 0 Slow
    0x31 24 dc 1 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow
    0x32 24 dc 1 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow
    --------------------------------------------

    Changing color depth or resolution doesn't change anything.

    I'm really sorry I have to bother you with my problems but I'm
    completely stuck and this thing appears to be really weird.
    If you need any additional information ask me.
    If this is the wrong place for this question, please point me to a
    better one.

    Thanks in advance for any hints
    Jan

  • Next message: Adam K Kirchhoff: "Re: Incomplete scene with OpenGL + direct rendering + mga"

    Relevant Pages

    • [opensuse] Xorg/beryl => compiz-fusion update
      ... When i run compiz: ... server glx vendor string: NVIDIA Corporation ... server glx extensions: ...
      (SuSE)
    • ATI Radeon 9700
      ... server glx vendor string: SGI ... server glx extensions: ... OpenGL renderer string: Mesa GLX Indirect ...
      (Debian-User)
    • Re: Linux in a binary world... a doomsday scenario
      ... > obviously not supposed to be like this - either card or driver is ... server glx vendor string: SGI ... server glx extensions: ...
      (Linux-Kernel)
    • Radeon 9200 & AGP 8x
      ... ii xlibmesa-dri 4.3.0.dfsg.1-1 Mesa 3D graphics library modules ... server glx vendor string: SGI ... server glx extensions: ...
      (Debian-User)
    • Re: DRI, working somewhat? But ...
      ... Here follows the glxinfo output, apparently fairly typical for a mach64 ... server glx vendor string: SGI ... server glx extensions: ...
      (Debian-User)