glutMainLoop in mac osx Lion freezes application - macos

Question

I'm trying to run an example GLUT program, but it only creates a white window and then freezes the application. I found it freezes when calling glutMainLoop (same if I call glutCheckLoop in a loop). Something I may be missing?
Here's the the sample code I found:
#include <stdlib.h>
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
// Question 1: In a GLUT program, how is control passed
// back to the programmer? How is this set up during
// initialization?
int win_width = 512;
int win_height = 512;
void display( void )
{
glClear( GL_COLOR_BUFFER_BIT );
glutSwapBuffers();
}
void reshape( int w, int h )
{
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
// Question 3: What do the calls to glOrtho()
// and glViewport() accomplish?
glOrtho( 0., 1., 0., 1., -1., 1. );
glViewport( 0, 0, w, h );
win_width = w;
win_height = h;
glutPostRedisplay();
}
void keyboard( unsigned char key, int x, int y ) {
switch(key) {
case 27: // Escape key
exit(0);
break;
}
}
int main (int argc, char *argv[]) {
glutInit( &argc, argv );
// Question 2: What does the parameter to glutInitDisplayMode()
// specify?
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( win_width, win_height );
glutCreateWindow( "Intro Graphics Assignment 1" );
glutDisplayFunc( display );
glutReshapeFunc( reshape );
glutKeyboardFunc( keyboard );
glutMainLoop();
return 0;
}

Answer 1

int main is not where you want glutMainLoop(), mate.
You should have that in your init method ie initGlutDisplay().
#include <stdlib.h>
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
// Question 1: In a GLUT program, how is control passed
// back to the programmer? How is this set up during
// initialization?
int win_width = 512;
int win_height = 512;
void display( void )
{
glClear( GL_COLOR_BUFFER_BIT );
glutSwapBuffers();
}
void reshape( int w, int h )
{
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
// Question 3: What do the calls to glOrtho()
// and glViewport() accomplish?
glOrtho( 0., 1., 0., 1., -1., 1. );
glViewport( 0, 0, w, h );
win_width = w;
win_height = h;
glutPostRedisplay();
}
void keyboard( unsigned char key, int x, int y ) {
switch(key) {
case 27: // Escape key
exit(0);
break;
}
}
int initGlutDisplay(int argc, char* argv[]){
glutInit( &argc, argv );
// Question 2: What does the parameter to glutInitDisplayMode()
// specify?
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( win_width, win_height );
glutCreateWindow( "Intro Graphics Assignment 1" );
glutDisplayFunc( display );
glutReshapeFunc( reshape );
glutKeyboardFunc( keyboard );
glutMainLoop();
return 0;
}
int main (int argc, char *argv[]) {
int win_width = 512;
int win_height = 512;
initGlutDisplay(argc, argv);
}
The above code should work perfectly.
EDIT
According to opengl
AGL is the old Carbon-based API with C bindings. The Carbon part
needed for windowing and event handling are not thread-safe. There is
no 64 bit version of this API.
I wonder if this is your issue. I would review the opengl Programming guide by apple to see if you missed any steps that might solve your problem.

Answer 2

It was a bug in the compiler (works now with gcc)