(Said Max Horn on the SDL mailing list...) Hi folks, based on Eric Wing's patch, I created the attached patch which fixes the OpenGL coordinate inversion bug in SDL. It works fine over here on 10.3 with Ryan's test program (which I also attached). There is another change in it: I removed the "- 1" in the two lines using CGDisplayPixelsHigh()... while I understand from a logical point of view why they *should* be correct, I checked the actual values computed that way, and they were off-by-one. After removing the " - 1", the returned mouse coordinates are correct. I checked this by moving the mouse to the screen top/bottom in fullscreen mode, BTW. With the change, the proper values 0 and 479 are returned (in 640x480 mode). Sam, you may still want to test on 10.1, it's very simple using Ryan's minimal test code :-) Cheers, Max (Here is the reproduction case for revision history's sake...) /* * To compile: * gcc -o test test.c `sdl-config --cflags` `sdl-config --libs` -framework OpenGL * * --ryan. */ #include <stdio.h> #include "SDL.h" #include "SDL_opengl.h" int main(int argc, char **argv) { Uint32 flags = SDL_OPENGL /* | SDL_FULLSCREEN */; SDL_Surface *screen; SDL_Event event; int done = 0; GLfloat ratio; SDL_Init(SDL_INIT_VIDEO); SDL_ShowCursor(0); if ((argv[1]) && (strcmp(argv[1], "--grab") == 0)) SDL_WM_GrabInput(SDL_GRAB_ON); screen = SDL_SetVideoMode(640, 480, 0, flags); if (!screen) return(42); ratio = ((GLfloat) screen->w) / ((GLfloat) screen->h); glClearColor( 0.0f, 0.0f, 0.0f, 0.0f ); glClearDepth( 1.0f ); glEnable( GL_DEPTH_TEST ); glDepthFunc( GL_LEQUAL ); glViewport( 0, 0, screen->w, screen->h); glMatrixMode( GL_PROJECTION ); glLoadIdentity(); gluPerspective( 45.0f, ratio, 0.1f, 100.0f ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); SDL_GL_SwapBuffers(); // eh, close enough. #define MAX_X 6.12 #define MAX_Y 4.50 while (!done) { int x, y; GLfloat glx, gly; if (!SDL_WaitEvent(&event)) break; switch (event.type) { case SDL_KEYUP: if (event.key.keysym.sym == SDLK_ESCAPE) done = 1; break; } SDL_GetMouseState(&x, &y); glx = ((((GLfloat) x) / ((GLfloat) screen->w)) - 0.5f) * MAX_X; gly = ((((GLfloat) y) / ((GLfloat) screen->h)) - 0.5f) * MAX_Y; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glTranslatef(glx,-gly,-6.0f); glBegin(GL_TRIANGLES); glColor3f(1,0,0); glVertex3f( 0.00f, 0.25f, 0.00f); glColor3f(0,1,0); glVertex3f(-0.25f, -0.25f, 0.00f); glColor3f(0,0,1); glVertex3f( 0.25f, -0.25f, 0.00f); glEnd(); SDL_GL_SwapBuffers(); } SDL_Quit(); return(0); } /* end of test.c ... */

/* Test the thread and mutex locking functions 
   Also exercises the system's signal/thread interaction
*/

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>

#include "SDL.h"
#include "SDL_mutex.h"
#include "SDL_thread.h"

static SDL_mutex *mutex = NULL;
static Uint32 mainthread;
static SDL_Thread *threads[6];

void printid(void)
{
	printf("Process %u:  exiting\n", SDL_ThreadID());
}
	
void terminate(int sig)
{
	printf("Process %u:  raising SIGTERM\n", SDL_ThreadID());
	raise(SIGTERM);
}
void closemutex(int sig)
{
	Uint32 id = SDL_ThreadID();
	int i;
	printf("Process %u:  Cleaning up...\n", id == mainthread ? 0 : id);
	for ( i=0; i<6; ++i )
		SDL_KillThread(threads[i]);
	SDL_DestroyMutex(mutex);
	exit(sig);
}
int Run(void *data)
{
	if ( SDL_ThreadID() == mainthread )
		signal(SIGTERM, closemutex);
	while ( 1 ) {
		printf("Process %u ready to work\n", SDL_ThreadID());
		if ( SDL_mutexP(mutex) < 0 ) {
			fprintf(stderr, "Couldn't lock mutex: %s", SDL_GetError());
			exit(1);
		}
		printf("Process %u, working!\n", SDL_ThreadID());
		SDL_Delay(1*1000);
		printf("Process %u, done!\n", SDL_ThreadID());
		if ( SDL_mutexV(mutex) < 0 ) {
			fprintf(stderr, "Couldn't unlock mutex: %s", SDL_GetError());
			exit(1);
		}
		/* If this sleep isn't done, then threads may starve */
		SDL_Delay(10);
	}
	return(0);
}

int main(int argc, char *argv[])
{
	int i;
	int maxproc = 6;

	/* Load the SDL library */
	if ( SDL_Init(0) < 0 ) {
		fprintf(stderr, "%s\n", SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit);

	if ( (mutex=SDL_CreateMutex()) == NULL ) {
		fprintf(stderr, "Couldn't create mutex: %s\n", SDL_GetError());
		exit(1);
	}

	mainthread = SDL_ThreadID();
	printf("Main thread: %u\n", mainthread);
	atexit(printid);
	for ( i=0; i<maxproc; ++i ) {
		if ( (threads[i]=SDL_CreateThread(Run, NULL)) == NULL )
			fprintf(stderr, "Couldn't create thread!\n");
	}
	signal(SIGINT, terminate);
	Run(NULL);

	return(0);	/* Never reached */
}