Mercurial > sdl-ios-xcode
annotate src/thread/generic/SDL_syscond.c @ 1192:54aa9aa32327
To: sdl@libsdl.org
From: Christian Walther <cwalther@gmx.ch>
Date: Fri, 18 Nov 2005 23:39:02 +0100
Subject: [SDL] Mouse position bugs on Mac OS X
The attached patch fixes a few bugs in SDL related to the mouse position
in windowed mode on Mac OS X, reproduced using the attached minimal test
program - at least here on 10.3.9, with SDL CVS from today. Could anyone
test whether the bugs exist and are fixed by the patch on 10.2 and 10.4?
1. When using OpenGL, the vertical mouse positions obtained through
events or SDL_GetMouseState() are off by one.
2. When using OpenGL, SDL_WarpMouse() inverts the y coordinate.
3. Clicks on the topmost pixel row of the window are not recognized.
1 and 2 do not occur in non-OpenGL mode, while 3 does. All three only
occur in windowed mode, not in fullscreen.
The cause for 1 and 3 is that in Cocoa, "the location of the mouse"
seems to be defined as "the location of the top left corner of the mouse
pointer's hot pixel" (this is not documented, it's just what I found out
here), which together with the fact that Cocoa's usual y coordinates
start at the bottom and increase upwards means that the y coordinate of
the mouse runs from 1 to h, not from 0 to h-1, in a window of height h.
If it does work on 10.2 and 10.4 (I'll try to test it as soon as I can,
but at the moment all I have at hand is 10.3.9), can this be applied to
the CVS?
-Christian
To: sdl@libsdl.org
From: Christian Walther <cwalther@gmx.ch>
Date: Mon, 28 Nov 2005 10:41:51 +0100
Subject: [SDL] Re: Mouse position bugs on Mac OS X
I wrote:
> I'll try to test it as soon as I can, but at the moment all I have at hand is 10.3.9
So, here are the results of my tests (with patched and unpatched
frameworks compiled with Xcode 1.5 (gcc 3.3) on 10.3.9):
On 10.1.5, my test program doesn't run because of "Undefined symbols:
SDL undefined reference to _CGMainDisplayID expected to be defined in
Carbon". I guess not supporting 10.1 was a deliberate decision then and
that's OK with me.
On 10.2.8, 10.3.9, and 10.4.0, the bugs exist as described in my
original post and are fixed by my patch. That is, there is no difference
between pre/post 10.3 and the patched version works correctly in all
combinations of GL/non-GL and windowed/fullscreen.
I therefore recommend the patch for inclusion.
-Christian
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Mon, 28 Nov 2005 13:58:26 +0000 |
| parents | b8d311d90021 |
| children | c9b51268668f |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
769
b8d311d90021
Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents:
297
diff
changeset
|
3 Copyright (C) 1997-2004 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 of the License, or (at your option) any later version. | |
| 9 | |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
|
252
e8157fcb3114
Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* An implementation of condition variables using semaphores and mutexes */ | |
| 29 /* | |
| 30 This implementation borrows heavily from the BeOS condition variable | |
| 31 implementation, written by Christopher Tate and Owen Smith. Thanks! | |
| 32 */ | |
| 33 | |
| 34 #include <stdio.h> | |
| 35 #include <stdlib.h> | |
| 36 | |
| 37 #include "SDL_error.h" | |
| 38 #include "SDL_thread.h" | |
| 39 | |
| 40 struct SDL_cond | |
| 41 { | |
| 42 SDL_mutex *lock; | |
| 43 int waiting; | |
| 44 int signals; | |
| 45 SDL_sem *wait_sem; | |
| 46 SDL_sem *wait_done; | |
| 47 }; | |
| 48 | |
| 49 /* Create a condition variable */ | |
| 50 SDL_cond * SDL_CreateCond(void) | |
| 51 { | |
| 52 SDL_cond *cond; | |
| 53 | |
| 54 cond = (SDL_cond *) malloc(sizeof(SDL_cond)); | |
| 55 if ( cond ) { | |
| 56 cond->lock = SDL_CreateMutex(); | |
| 57 cond->wait_sem = SDL_CreateSemaphore(0); | |
| 58 cond->wait_done = SDL_CreateSemaphore(0); | |
| 59 cond->waiting = cond->signals = 0; | |
| 60 if ( ! cond->lock || ! cond->wait_sem || ! cond->wait_done ) { | |
| 61 SDL_DestroyCond(cond); | |
| 62 cond = NULL; | |
| 63 } | |
| 64 } else { | |
| 65 SDL_OutOfMemory(); | |
| 66 } | |
| 67 return(cond); | |
| 68 } | |
| 69 | |
| 70 /* Destroy a condition variable */ | |
| 71 void SDL_DestroyCond(SDL_cond *cond) | |
| 72 { | |
| 73 if ( cond ) { | |
| 74 if ( cond->wait_sem ) { | |
| 75 SDL_DestroySemaphore(cond->wait_sem); | |
| 76 } | |
| 77 if ( cond->wait_done ) { | |
| 78 SDL_DestroySemaphore(cond->wait_done); | |
| 79 } | |
| 80 if ( cond->lock ) { | |
| 81 SDL_DestroyMutex(cond->lock); | |
| 82 } | |
| 83 free(cond); | |
| 84 } | |
| 85 } | |
| 86 | |
| 87 /* Restart one of the threads that are waiting on the condition variable */ | |
| 88 int SDL_CondSignal(SDL_cond *cond) | |
| 89 { | |
| 90 if ( ! cond ) { | |
| 91 SDL_SetError("Passed a NULL condition variable"); | |
| 92 return -1; | |
| 93 } | |
| 94 | |
| 95 /* If there are waiting threads not already signalled, then | |
| 96 signal the condition and wait for the thread to respond. | |
| 97 */ | |
| 98 SDL_LockMutex(cond->lock); | |
| 99 if ( cond->waiting > cond->signals ) { | |
| 100 ++cond->signals; | |
| 101 SDL_SemPost(cond->wait_sem); | |
| 102 SDL_UnlockMutex(cond->lock); | |
| 103 SDL_SemWait(cond->wait_done); | |
| 104 } else { | |
| 105 SDL_UnlockMutex(cond->lock); | |
| 106 } | |
| 107 | |
| 108 return 0; | |
| 109 } | |
| 110 | |
| 111 /* Restart all threads that are waiting on the condition variable */ | |
| 112 int SDL_CondBroadcast(SDL_cond *cond) | |
| 113 { | |
| 114 if ( ! cond ) { | |
| 115 SDL_SetError("Passed a NULL condition variable"); | |
| 116 return -1; | |
| 117 } | |
| 118 | |
| 119 /* If there are waiting threads not already signalled, then | |
| 120 signal the condition and wait for the thread to respond. | |
| 121 */ | |
| 122 SDL_LockMutex(cond->lock); | |
| 123 if ( cond->waiting > cond->signals ) { | |
| 124 int i, num_waiting; | |
| 125 | |
| 126 num_waiting = (cond->waiting - cond->signals); | |
| 127 cond->signals = cond->waiting; | |
| 128 for ( i=0; i<num_waiting; ++i ) { | |
| 129 SDL_SemPost(cond->wait_sem); | |
| 130 } | |
| 131 /* Now all released threads are blocked here, waiting for us. | |
| 132 Collect them all (and win fabulous prizes!) :-) | |
| 133 */ | |
| 134 SDL_UnlockMutex(cond->lock); | |
| 135 for ( i=0; i<num_waiting; ++i ) { | |
| 136 SDL_SemWait(cond->wait_done); | |
| 137 } | |
| 138 } else { | |
| 139 SDL_UnlockMutex(cond->lock); | |
| 140 } | |
| 141 | |
| 142 return 0; | |
| 143 } | |
| 144 | |
| 145 /* Wait on the condition variable for at most 'ms' milliseconds. | |
| 146 The mutex must be locked before entering this function! | |
| 147 The mutex is unlocked during the wait, and locked again after the wait. | |
| 148 | |
| 149 Typical use: | |
| 150 | |
| 151 Thread A: | |
| 152 SDL_LockMutex(lock); | |
| 153 while ( ! condition ) { | |
| 154 SDL_CondWait(cond); | |
| 155 } | |
| 156 SDL_UnlockMutex(lock); | |
| 157 | |
| 158 Thread B: | |
| 159 SDL_LockMutex(lock); | |
| 160 ... | |
| 161 condition = true; | |
| 162 ... | |
| 163 SDL_UnlockMutex(lock); | |
| 164 */ | |
| 165 int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms) | |
| 166 { | |
| 167 int retval; | |
| 168 | |
| 169 if ( ! cond ) { | |
| 170 SDL_SetError("Passed a NULL condition variable"); | |
| 171 return -1; | |
| 172 } | |
| 173 | |
| 174 /* Obtain the protection mutex, and increment the number of waiters. | |
| 175 This allows the signal mechanism to only perform a signal if there | |
| 176 are waiting threads. | |
| 177 */ | |
| 178 SDL_LockMutex(cond->lock); | |
| 179 ++cond->waiting; | |
| 180 SDL_UnlockMutex(cond->lock); | |
| 181 | |
| 182 /* Unlock the mutex, as is required by condition variable semantics */ | |
| 183 SDL_UnlockMutex(mutex); | |
| 184 | |
| 185 /* Wait for a signal */ | |
| 186 if ( ms == SDL_MUTEX_MAXWAIT ) { | |
| 187 retval = SDL_SemWait(cond->wait_sem); | |
| 188 } else { | |
| 189 retval = SDL_SemWaitTimeout(cond->wait_sem, ms); | |
| 190 } | |
| 191 | |
| 192 /* Let the signaler know we have completed the wait, otherwise | |
| 193 the signaler can race ahead and get the condition semaphore | |
| 194 if we are stopped between the mutex unlock and semaphore wait, | |
| 195 giving a deadlock. See the following URL for details: | |
| 196 http://www-classic.be.com/aboutbe/benewsletter/volume_III/Issue40.html | |
| 197 */ | |
| 198 SDL_LockMutex(cond->lock); | |
| 199 if ( cond->signals > 0 ) { | |
| 200 /* If we timed out, we need to eat a condition signal */ | |
| 201 if ( retval > 0 ) { | |
| 202 SDL_SemWait(cond->wait_sem); | |
| 203 } | |
| 204 /* We always notify the signal thread that we are done */ | |
| 205 SDL_SemPost(cond->wait_done); | |
| 206 | |
| 207 /* Signal handshake complete */ | |
| 208 --cond->signals; | |
| 209 } | |
| 210 --cond->waiting; | |
| 211 SDL_UnlockMutex(cond->lock); | |
| 212 | |
| 213 /* Lock the mutex, as is required by condition variable semantics */ | |
| 214 SDL_LockMutex(mutex); | |
| 215 | |
| 216 return retval; | |
| 217 } | |
| 218 | |
| 219 /* Wait on the condition variable forever */ | |
| 220 int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex) | |
| 221 { | |
| 222 return SDL_CondWaitTimeout(cond, mutex, SDL_MUTEX_MAXWAIT); | |
| 223 } |