Mercurial > sdl-ios-xcode
view README @ 876:9e84d106ec19
(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 ... */
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Mon, 22 Mar 2004 09:38:20 +0000 |
parents | 61b7f5eed0e8 |
children | ca3718c215af |
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Simple DirectMedia Layer (SDL) Version 1.2 --- http://www.libsdl.org/ This is the Simple DirectMedia Layer, a general API that provides low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D framebuffer across multiple platforms. SDL is written in C, but works with C++ natively, and has bindings to several other languages, including Ada, C#, Eiffel, Java, Lua, ML, Objective C, Perl, PHP, Pike, Python, and Ruby. The current version supports Linux, Windows, BeOS, MacOS, MacOS X, FreeBSD, OpenBSD, BSD/OS, Solaris, IRIX, and QNX. The code contains support for Windows CE, AmigaOS, Dreamcast, Atari, NetBSD, AIX, OSF/Tru64, RISC OS, and SymbianOS, but these are not officially supported. This library is distributed under GNU LGPL version 2, which can be found in the file "COPYING". This license allows you to use SDL freely in commercial programs as long as you link with the dynamic library. The best way to learn how to use SDL is to check out the header files in the "include" subdirectory and the programs in the "test" subdirectory. The header files and test programs are well commented and always up to date. More documentation is available in HTML format in "./docs/index.html" The test programs in the "test" subdirectory are in the public domain. Frequently asked questions are answered online: http://www.libsdl.org/faq.php If you need help with the library, or just want to discuss SDL related issues, you can join the developers mailing list: http://www.libsdl.org/mailing-list.php Enjoy! Sam Lantinga (slouken@libsdl.org)