issue with "DrawBitmapString" for WSL2 in glkit.c

[BAmercury]

Hey @ericstoneking , hope all is well. Wanted to share something I found

WSL2 supports native X-11 forwarding and has support for discrete GPUs
https://learn.microsoft.com/en-us/windows/wsl/tutorials/gui-apps

On my machine, I followed the setup steps as normal for the WSL:

& bash
& sudo apt update
& sudo apt-get install vim-gtk
& sudo apt install gcc
& sudo apt install g++ [[if needed.  LWS]]
& DISPLAY=:1 gvim #check that opens a xming display window
& sudo apt-cache search glut
& sudo apt-get install freeglut3-dev
& sudo apt-get install libglfw3-dev

I did not need to export the display, with WSL2 it should be set such that DISPLAY=:0

What I did have to do for things to work and use my GPU on my laptop:

export MESA_D3D12_DEFAULT_ADAPTER_NAME=NVIDIA
export LIBGL_ALWAYS_SOFTWARE=false

Can check with this: glxinfo | grep renderer

    GLX_MESA_copy_sub_buffer, GLX_MESA_gl_interop, GLX_MESA_query_renderer,
    GLX_MESA_copy_sub_buffer, GLX_MESA_gl_interop, GLX_MESA_query_renderer,
Extended renderer info (GLX_MESA_query_renderer):
OpenGL renderer string: D3D12 (NVIDIA RTX A3000 Laptop GPU)

Tried to run ./42, the windows would come up but they were black. Then the could would seg fault.

So ran ./42 with gdb and saw this issue:

#0  0x00000000000000e0 in ?? ()
#1  0x00007ffff1cbfd80 in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#2  0x00007ffff1cf31cd in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#3  0x00007ffff1cf3af5 in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#4  0x00007ffff1cf491d in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#5  0x00007ffff16f4fc8 in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#6  0x00007ffff16f522a in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#7  0x00007ffff1cf418d in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#8  0x00007ffff16b7f40 in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#9  0x00007ffff16b897b in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#10 0x00007ffff16bae16 in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#11 0x00007ffff134323d in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#12 0x00007ffff1257965 in ?? () from /lib/x86_64-linux-gnu/libgallium-25.2.8-0ubuntu0.24.04.1.so
#13 0x00007ffff7f253fd in glutBitmapCharacter (fontID=0x7ffff7f4e6f8 <glutBitmap8By13>, character=<optimized out>)
    at /usr/src/freeglut-3.4.0-1build1/src/fg_font.c:136
#14 0x000055555563a10c in DrawBitmapString (font=0x7ffff7f4e6f8 <glutBitmap8By13>,
    string=0x7fffffffda00 "UTC 099-00:00:00.00") at ./Kit/Source/glkit.c:37
#15 0x0000555555616477 in DrawCamHUD () at ./Source/42gl.c:714
#16 0x000055555561bbe7 in DrawNearAuxObjects () at ./Source/42gl.c:1662
#17 0x000055555562298f in CamRenderExec () at ./Source/42gl.c:2573
#18 0x00007ffff7f16fb3 in fghRedrawWindow (window=window@entry=0x5555570a8b20)
    at /usr/src/freeglut-3.4.0-1build1/src/fg_main.c:133
#19 0x00007ffff7f208ad in fgProcessWork (window=window@entry=0x5555570a8b20)
    at /usr/src/freeglut-3.4.0-1build1/src/fg_main.c:435
#20 0x00007ffff7f22099 in fghcbProcessWork (window=0x5555570a8b20, enumerator=0x7fffffffdc40)
    at /usr/src/freeglut-3.4.0-1build1/src/fg_main.c:157
#21 0x00007ffff7f215c9 in fgEnumWindows (enumCallback=enumCallback@entry=0x7ffff7f22060 <fghcbProcessWork>,
    enumerator=enumerator@entry=0x7fffffffdc40) at /usr/src/freeglut-3.4.0-1build1/src/fg_structure.c:406
#22 0x00007ffff7f21888 in fghProcessWork () at /usr/src/freeglut-3.4.0-1build1/src/fg_main.c:172
--Type <RET> for more, q to quit, c to continue without paging--
#23 glutMainLoopEvent () at /usr/src/freeglut-3.4.0-1build1/src/fg_main.c:457
#24 0x00007ffff7f21924 in glutMainLoop () at /usr/src/freeglut-3.4.0-1build1/src/fg_main.c:489
#25 0x000055555563a0cf in HandoffToGui (argc=1, argv=0x7fffffffde68) at ./Source/42glut.c:1399
#26 0x000055555555b74e in exec (argc=1, argv=0x7fffffffde68) at ./Source/42exec.c:415
#27 0x0000555555559cad in main (argc=1, argv=0x7fffffffde68) at ./Source/42main.c:41

I saw it had something to do with the DrawBitmapString function. Now as any good GNC engineer I just added this bit to glkit.c

From this:

void DrawBitmapString(void *font, const char *string)
{
      const char *c;
      for(c=string; *c != '\0'; c++) {
         glutBitmapCharacter(font, *c);
      }
}

To this:

void DrawBitmapString(void *font, const char *string)
{
#ifndef ENABLE_GL_TEXT
    (void)font;
    (void)string;
    // WSL/GLUT bitmap text disabled: crashes inside glutBitmapCharacter
    return;
#else
    const char *c;
    for (c = string; *c != '\0'; c++)
        glutBitmapCharacter(font, *c);
#endif
}

Essentially just turned it off.

And now everything works, minus lacking the text:

GLFW also had this issue, and then I turned that text off and it works as well now. Let me know your thoughts.