glut help?

[ninja9578]

I don't understand why this code is failing. It doesn't display the menu, but the cursor changes as if it was there. Then it crashes and prints out that it encountered a segmentation fault and did a core dump. static unsigned short daynight = 0; void DayorNight(int choice){ daynight = (choice - 1) * 50; //either 0 or 50 } int main (int argc, char** argv){ glutInit (&argc, argv); glutInitDisplayMode (GLUT_DOUBLE|GLUT_RGB); glutInitWindowSize (800, 600); glutInitWindowPosition (0, 0); glutCreateWindow (argv[0]); init (); glutReshapeFunc (reshape); glutDisplayFunc (display); glutIdleFunc(animate); glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glutMouseFunc(checkmouse); InitializeCars(); //problematic code? glutCreateMenu(DayorNight); glutAddMenuEntry("Night", 1); glutAddMenuEntry("Day", 2); glutAttachMenu(GLUT_RIGHT_BUTTON); // //set up the timers seekchange = clock() + 150000; ResetTime = clock() + 33; //should be 30FPS glutMainLoop (); return 0; } It's C if that's not obvious and everything else works until I right click on the screen.

[Ynot]

never used glut but just looking at it, try changing "static unsigned short daynight" to "static int daynight" and making your DayorNight function static

[Replicon]

Run a debugger on the core dump and binary and show us what your stack trace looks like.

[ninja9578]

Umm... How do I go about doing that? I'm not using an IDE, I'm compiling from the command line.

[Replicon]

GDB is a command line debugger. Google GDB tutorial. Here's a sample run: ~/sandbox/foo/$ cat > test.cpp int main(void) { int x = 5, y = 0; int z = x/y; return 0; } ~/sandbox/foo/$ g++ -g -o test test.cpp ~/sandbox/foo/$ gdb test GNU gdb Red Hat Linux (6.3.0.0-1.132.EL3rh) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"...Using host libthread_db library "/lib/tls/libthread_db.so.1". (gdb) run Starting program: /home/xxxxx/sandbox/foo/test Program received signal SIGFPE, Arithmetic exception. 0x08048384 in main () at test.cpp:3 3 int z = x/y; (gdb) quit The program is running. Exit anyway? (y or n) y ~/sandbox/foo/$ You can also specify a core file with the binary, and it will just tell you where it failed. From the GDB man page: You can also start with both an executable program and a core file specified: gdb program core Hope this helps. If you're going to be using OpenGL or doing anything beyond some silly single-file exercise, you really need to learn to use a debugger anyway (and while gdb isn't really the easiest to use, it's a good learning tool).