Segfault on Ubuntu about sdl-ball

[danielesegato]

I've compiled the current master version (6fedb29).

It crashes the same for me on Ubuntu 21.04.

I've compiled with debugging symbols and this is the backtrace:

#0  0x00007f8574b76885 in compile_vertex_list (ctx=ctx@entry=0x55cb88b7a940) at ../src/mesa/vbo/vbo_save_api.c:746
#1  0x00007f8574b76e2b in wrap_buffers (ctx=0x55cb88b7a940) at ../src/mesa/vbo/vbo_save_api.c:868
#2  0x00007f8574b7742c in upgrade_vertex (ctx=ctx@entry=0x55cb88b7a940, attr=attr@entry=7, newsz=newsz@entry=2) at ../src/mesa/vbo/vbo_save_api.c:975
#3  0x00007f8574b776b9 in fixup_vertex (newType=5126, sz=2, attr=7, ctx=0x55cb88b7a940) at ../src/mesa/vbo/vbo_save_api.c:1079
#4  _save_TexCoord2f (x=0, y=0) at ../src/mesa/vbo/vbo_attrib_tmp.h:268
#5  0x000055cb87963f7e in mkDLscene(unsigned int*, textureClass) (dl=0x7ffe5f66ff90, tex=...) at main.cpp:2934
#6  0x000055cb8796c959 in main(int, char**) (argc=1, argv=0x7ffe5f6a7828) at main.cpp:4056

the main.c portion is this one

void mkDLscene(GLuint *dl,textureClass tex)
{
  //Scenen
  *dl = glGenLists(1);
  glNewList(*dl,GL_COMPILE);
    glLoadIdentity();
    glTranslatef( 0.0f, 0.0f, -3.0 );
    glColor4f(1.0, 1.0, 1.0, 1.0);
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, tex.prop.texture);
    glBegin( GL_POINTS );
      glVertex3f( -1.60, 1.25, 0.0 );
    glEnd( );
    glBegin( GL_QUADS );
      //venstre kant
      glTexCoord2f(0.0f,0.0f);glVertex3f( -1.66, 1.25, 0.0 ); // <------ HERE specifically
      glTexCoord2f(1.0f,0.0f);glVertex3f( -1.60, 1.25, 0.0 );
      glTexCoord2f(1.0f,-1.0f);glVertex3f( -1.60,-1.25, 0.0 );
      glTexCoord2f(0.0f,-1.0f);glVertex3f( -1.66,-1.25, 0.0 );
      //højre kant
      glTexCoord2f(0.0f,0.0f);glVertex3f( 1.66, 1.25, 0.0 );
      glTexCoord2f(1.0f,0.0f);glVertex3f( 1.60, 1.25, 0.0 );
      glTexCoord2f(1.0f,-1.0f);glVertex3f( 1.60,-1.25, 0.0 );
      glTexCoord2f(0.0f,-1.0f);glVertex3f( 1.66,-1.25, 0.0 );
    glEnd( );
  glEndList();
}

Ubuntu version for libgl1-mesa-dri is 21.0.3-0ubuntu0.3 amd64

which means the code of the crashing file happens here https://github.com/grate-driver/mesa/blob/21.0.3/src/mesa/vbo/vbo_save_api.c#L746

I really don't get the No such file or directory in the backtrace.

I don't see anything wrong with the code and my experience with C++ and Open-GL is too limited to know what's causing this.

[danielesegato]

If I comment out all this part:

    glBegin( GL_QUADS );
      //venstre kant
      glTexCoord2f(0.0f,0.0f);glVertex3f( -1.66, 1.25, 0.0 ); // <------ HERE specifically
      glTexCoord2f(1.0f,0.0f);glVertex3f( -1.60, 1.25, 0.0 );
      glTexCoord2f(1.0f,-1.0f);glVertex3f( -1.60,-1.25, 0.0 );
      glTexCoord2f(0.0f,-1.0f);glVertex3f( -1.66,-1.25, 0.0 );
      //højre kant
      glTexCoord2f(0.0f,0.0f);glVertex3f( 1.66, 1.25, 0.0 );
      glTexCoord2f(1.0f,0.0f);glVertex3f( 1.60, 1.25, 0.0 );
      glTexCoord2f(1.0f,-1.0f);glVertex3f( 1.60,-1.25, 0.0 );
      glTexCoord2f(0.0f,-1.0f);glVertex3f( 1.66,-1.25, 0.0 );
    glEnd( );

the game works, and I've seen no issue with it (maybe it does not draw some border?

[DusteDdk]

Wow, I wonder what I did that was so horrible that it made mesa crash xD well, to be honest, sdl-ball was my second-ever opengl program, I had no idea what I was doing xD I vaguely recall just sitting and adjusting floats until stuff "looked right" on the screen :D