Mercurial > sdl-ios-xcode
view src/cdrom/os2/SDL_syscdrom.c @ 4139:568c9b3c0167 SDL-1.2
* Added configure option --enable-screensaver, to allow enabling the screensaver by default.
* Use XResetScreenSaver() instead of disabling screensaver entirely.
Full discussion summary from Erik on the SDL mailing list:
Current behaviour
=================
SDL changes the user's display power management settings without
permission from the user and without telling the user.
The interface that it uses to do so is DPMSDisable/DPMSEnable, which
should only ever be used by configuration utilities like KControl, never
by normal application programs, let alone by the libraries that they
use. Using an interface that is not at all intended for what SDL tries
to achieve means that it will not work as it should. Firstly, the power
management is completely disabled during the whole lifetime of the SDL
program, not only when it should be. Secondly, it makes SDL
non-reentrant, meaning that things will break when multiple SDL programs
are clients of the same X server simultaneously. Thirdly, no cleanup
mechanism ensures that the setting is restored if the client does not do
that (for example if it crashes).
In addition to that, this interface is broken on xorg,
[http://bugs.freedesktop.org/show_bug.cgi?id=13962], so what SDL tries
to do does not work at all on that implementation of the X Window
System. (The reason that the DPMSEnable works in KControl is that it
calls DPMSSetTimeout immediately after,
[http://websvn.kde.org/tags/KDE/3.5.9/kdebase/kcontrol/energy/energy.cpp?annotate=774532#l343]).
The problems that the current behaviour causes
==============================================
1. Information leak. When the user is away, someone might see what the
user has on the display when the user counts on the screensaver
preventing this. This does not even require physical access to the
workstation, it is enough to see it from a distance.
2. Draining battery. An SDL program that runs on a laptop will quickly
drain the battery while the user is away. The system will soon shut down
and require recharging before being usable again, while it should in
fact have consumed very little energy if the user's settings would have
been obeyed.
3. Wasting energy. Even if battery issues are not considered, energy as
such is wasted.
4. Display wear. The display may be worn out.
The problems that the current behaviour tries to solve
======================================================
1. Preventing screensaver while playing movies.
Many SDL applications are media players. They have reasons to prevent
screensavers from being activated while a movie is being played. When a
user clicks on the play button it can be interpreted as saying "play
this movie, but do not turn off the display while playing it, because I
will watch it even though I do not interact with the system".
2. Preventing screensaver when some input bypasses X.
Sometimes SDL uses input from another source than the X server, so
that the X server is bypassed. This obviously breaks the screensaver
handling. SDL tries to work around that.
3. Preventing screensaver when all input bypasses X.
There is something called Direct Graphics Access mode, where a
program takes control of both the display and the input devices from the
X server. This obviously means that the X server can not handle the
screensaver alone, since screensaver handling depends on input handling.
SDL does not do what it should to help the X server to handle the
screensaver. Nor does SDL take care of screeensaver handling itself. SDL
simply disables the screensaver completely.
How the problems should be solved
=================================
The correct way for an application program to prevent the screensaver
under X is to call XResetScreenSaver. This was recently discovered and
implemented by the mplayer developers,
[http://svn.mplayerhq.hu/mplayer?view=rev&revision=25637]. SDL needs to
wrap this in an API call (SDL_ResetScreenSaver) and implement it for the
other video targets (if they do not have a corresponding call, SDL
should do what it takes on that particular target, for example sending
fake key events).
1. When a movie is played, the player should reset the screensaver when
the animation is advanced to a new frame. The same applies to anything
similar, like slideshows.
2. When the X server is handling input, it must handle all input
(keyboards, mice, gamepads, ...). This is necessary, not only to be able
to handle the screensaver, but also so that it can send the events to
the correct (the currently active) client. If there is an input device
that the X server can not handle for some reason (such as lack of Plug
and Play capability), the program that handles the device as a
workaround must simulate what would happen if the X server would have
handled the device, by calling XResetScreenSaver when input is received
from the device.
3. When the X server is not handling the input, it depends on the
program that does to call XResetScreenSaver whenever an input event
occurs. Alternatively the program must handle the screensaver countdown
internally and call XActivateScreenSaver.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 29 Feb 2008 13:55:44 +0000 |
parents | 92947e3a18db |
children | 782fd950bd46 c121d94672cb a1b03ba2fcd0 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #ifdef SDL_CDROM_OS2 /* Functions for system-level CD-ROM audio control */ #define INCL_MCIOS2 #include <os2.h> #include <os2me.h> #include "SDL_cdrom.h" #include "../SDL_syscdrom.h" /* Size of MCI result buffer (in bytes) */ #define MCI_CMDRETBUFSIZE 128 /* The maximum number of CD-ROM drives we'll detect */ #define MAX_DRIVES 16 /* A list of available CD-ROM drives */ static char *SDL_cdlist[MAX_DRIVES]; //static dev_t SDL_cdmode[MAX_DRIVES]; /* The system-dependent CD control functions */ static const char *SDL_SYS_CDName(int drive); static int SDL_SYS_CDOpen(int drive); static int SDL_SYS_CDGetTOC(SDL_CD *cdrom); static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position); static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length); static int SDL_SYS_CDPause(SDL_CD *cdrom); static int SDL_SYS_CDResume(SDL_CD *cdrom); static int SDL_SYS_CDStop(SDL_CD *cdrom); static int SDL_SYS_CDEject(SDL_CD *cdrom); static void SDL_SYS_CDClose(SDL_CD *cdrom); /* MCI Timing Functions */ #define MCI_MMTIMEPERSECOND 3000 #define FRAMESFROMMM(mmtime) (((mmtime)*CD_FPS)/MCI_MMTIMEPERSECOND) /* Ready for MCI CDAudio Devices */ int SDL_SYS_CDInit(void) { int i; /* generig counter */ MCI_SYSINFO_PARMS msp; /* Structure to MCI SysInfo parameters */ CHAR SysInfoRet[MCI_CMDRETBUFSIZE]; /* Buffer for MCI Command result */ /* Fill in our driver capabilities */ SDL_CDcaps.Name = SDL_SYS_CDName; SDL_CDcaps.Open = SDL_SYS_CDOpen; SDL_CDcaps.GetTOC = SDL_SYS_CDGetTOC; SDL_CDcaps.Status = SDL_SYS_CDStatus; SDL_CDcaps.Play = SDL_SYS_CDPlay; SDL_CDcaps.Pause = SDL_SYS_CDPause; SDL_CDcaps.Resume = SDL_SYS_CDResume; SDL_CDcaps.Stop = SDL_SYS_CDStop; SDL_CDcaps.Eject = SDL_SYS_CDEject; SDL_CDcaps.Close = SDL_SYS_CDClose; /* Get the number of CD ROMs in the System */ /* Clean SysInfo structure */ SDL_memset(&msp, 0x00, sizeof(MCI_SYSINFO_PARMS)); /* Prepare structure to Ask Numer of Audio CDs */ msp.usDeviceType = MCI_DEVTYPE_CD_AUDIO; /* CD Audio Type */ msp.pszReturn = (PSZ)&SysInfoRet; /* Return Structure */ msp.ulRetSize = MCI_CMDRETBUFSIZE; /* Size of ret struct */ if (LOUSHORT(mciSendCommand(0,MCI_SYSINFO, MCI_SYSINFO_QUANTITY | MCI_WAIT, (PVOID)&msp, 0)) != MCIERR_SUCCESS) return(CD_ERROR); SDL_numcds = atoi(SysInfoRet); if (SDL_numcds > MAX_DRIVES) SDL_numcds = MAX_DRIVES; /* Limit maximum CD number */ /* Get and Add their system name to the SDL_cdlist */ msp.pszReturn = (PSZ)&SysInfoRet; /* Return Structure */ msp.ulRetSize = MCI_CMDRETBUFSIZE; /* Size of ret struct */ msp.usDeviceType = MCI_DEVTYPE_CD_AUDIO; /* CD Audio Type */ for (i=0; i<SDL_numcds; i++) { msp.ulNumber = i+1; mciSendCommand(0,MCI_SYSINFO, MCI_SYSINFO_NAME | MCI_WAIT,&msp, 0); SDL_cdlist[i] = SDL_strdup(SysInfoRet); if ( SDL_cdlist[i] == NULL ) { SDL_OutOfMemory(); return(-1); } } return(0); } /* Return CDAudio System Dependent Device Name - Ready for MCI*/ static const char *SDL_SYS_CDName(int drive) { return(SDL_cdlist[drive]); } /* Open CDAudio Device - Ready for MCI */ static int SDL_SYS_CDOpen(int drive) { MCI_OPEN_PARMS mop; MCI_SET_PARMS msp; MCI_GENERIC_PARMS mgp; /* Open the device */ mop.hwndCallback = (HWND)NULL; // None mop.usDeviceID = (USHORT)NULL; // Will be returned. mop.pszDeviceType = (PSZ)SDL_cdlist[drive]; // CDAudio Device if (LOUSHORT(mciSendCommand(0,MCI_OPEN,MCI_WAIT,&mop, 0)) != MCIERR_SUCCESS) return(CD_ERROR); /* Set time format */ msp.hwndCallback = (HWND)NULL; // None msp.ulTimeFormat = MCI_FORMAT_MSF; // Minute : Second : Frame structure msp.ulSpeedFormat = (ULONG)NULL; // No change msp.ulAudio = (ULONG)NULL; // No Channel msp.ulLevel = (ULONG)NULL; // No Volume msp.ulOver = (ULONG)NULL; // No Delay msp.ulItem = (ULONG)NULL; // No item msp.ulValue = (ULONG)NULL; // No value for item flag if (LOUSHORT(mciSendCommand(mop.usDeviceID,MCI_SET,MCI_WAIT | MCI_SET_TIME_FORMAT,&msp, 0)) == MCIERR_SUCCESS) return (mop.usDeviceID); /* Error setting time format? - Close opened device */ mgp.hwndCallback = (HWND)NULL; // None mciSendCommand(mop.usDeviceID,MCI_CLOSE,MCI_WAIT,&mgp, 0); return(CD_ERROR); } /* Get CD Table Of Contents - Ready for MCI */ static int SDL_SYS_CDGetTOC(SDL_CD *cdrom) { MCI_TOC_PARMS mtp; MCI_STATUS_PARMS msp; MCI_TOC_REC * mtr; INT i; /* Correction because MCI cannot read TOC while CD is playing (it'll stop!) */ if (cdrom->status == CD_PLAYING || cdrom->status == CD_PAUSED) return 0; /* Get Number of Tracks */ msp.hwndCallback = (HWND)NULL; /* None */ msp.ulReturn = (ULONG)NULL; /* We want this information */ msp.ulItem = MCI_STATUS_NUMBER_OF_TRACKS; msp.ulValue = (ULONG)NULL; /* No additional information */ if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) return(CD_ERROR); cdrom->numtracks = msp.ulReturn; if ( cdrom->numtracks > SDL_MAX_TRACKS ) { cdrom->numtracks = SDL_MAX_TRACKS; } /* Alocate space for TOC data */ mtr = (MCI_TOC_REC *)SDL_malloc(cdrom->numtracks*sizeof(MCI_TOC_REC)); if ( mtr == NULL ) { SDL_OutOfMemory(); return(-1); } /* Get TOC from CD */ mtp.pBuf = mtr; mtp.ulBufSize = cdrom->numtracks*sizeof(MCI_TOC_REC); if (LOUSHORT(mciSendCommand(cdrom->id,MCI_GETTOC,MCI_WAIT,&mtp, 0)) != MCIERR_SUCCESS) { SDL_OutOfMemory(); SDL_free(mtr); return(CD_ERROR); } /* Fill SDL Tracks Structure */ for (i=0; i<cdrom->numtracks; i++) { /* Set Track ID */ cdrom->track[i].id = (mtr+i)->TrackNum; /* Set Track Type */ msp.hwndCallback = (HWND)NULL; /* None */ msp.ulReturn = (ULONG)NULL; /* We want this information */ msp.ulItem = MCI_CD_STATUS_TRACK_TYPE; msp.ulValue = (ULONG)((mtr+i)->TrackNum); /* Track Number? */ if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_TRACK | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) { SDL_free(mtr); return (CD_ERROR); } if (msp.ulReturn==MCI_CD_TRACK_AUDIO) cdrom->track[i].type = SDL_AUDIO_TRACK; else cdrom->track[i].type = SDL_DATA_TRACK; /* Set Track Length - values from MCI are in MMTIMEs - 3000 MMTIME = 1 second */ cdrom->track[i].length = FRAMESFROMMM((mtr+i)->ulEndAddr - (mtr+i)->ulStartAddr); /* Set Track Offset */ cdrom->track[i].offset = FRAMESFROMMM((mtr+i)->ulStartAddr); } SDL_free(mtr); return(0); } /* Get CD-ROM status - Ready for MCI */ static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position) { CDstatus status; MCI_STATUS_PARMS msp; /* Get Status from MCI */ msp.hwndCallback = (HWND)NULL; /* None */ msp.ulReturn = (ULONG)NULL; /* We want this information */ msp.ulItem = MCI_STATUS_MODE; msp.ulValue = (ULONG)NULL; /* No additional information */ if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) status = CD_ERROR; else { switch(msp.ulReturn) { case MCI_MODE_NOT_READY: status = CD_TRAYEMPTY; break; case MCI_MODE_PAUSE: status = CD_PAUSED; break; case MCI_MODE_PLAY: status = CD_PLAYING; break; case MCI_MODE_STOP: status = CD_STOPPED; break; /* These cases should not occour */ case MCI_MODE_RECORD: case MCI_MODE_SEEK: default: status = CD_ERROR; break; } } /* Determine position */ if (position != NULL) /* The SDL $&$&%# CDROM call sends NULL pointer here! */ { if ((status == CD_PLAYING) || (status == CD_PAUSED)) { /* Get Position */ msp.hwndCallback = (HWND)NULL; /* None */ msp.ulReturn = (ULONG)NULL; /* We want this information */ msp.ulItem = MCI_STATUS_POSITION; msp.ulValue = (ULONG)NULL; /* No additiona info */ if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) != MCIERR_SUCCESS) return (CD_ERROR); /* Convert from MSF (format selected in the Open process) to Frames (format that will be returned) */ *position = MSF_TO_FRAMES(MSF_MINUTE(msp.ulReturn),MSF_SECOND(msp.ulReturn),MSF_FRAME(msp.ulReturn)); } else *position = 0; } return(status); } /* Start play - Ready for MCI */ static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length) { MCI_GENERIC_PARMS mgp; MCI_STATUS_PARMS msp; MCI_PLAY_PARMS mpp; ULONG min,sec,frm; /* Start MSF */ FRAMES_TO_MSF(start, &min, &sec, &frm); MSF_MINUTE(mpp.ulFrom) = min; MSF_SECOND(mpp.ulFrom) = sec; MSF_FRAME(mpp.ulFrom) = frm; /* End MSF */ FRAMES_TO_MSF(start+length, &min, &sec, &frm); MSF_MINUTE(mpp.ulTo) = min; MSF_SECOND(mpp.ulTo) = sec; MSF_FRAME(mpp.ulTo) = frm; #ifdef DEBUG_CDROM fprintf(stderr, "Trying to play from %d:%d:%d to %d:%d:%d\n", playtime.cdmsf_min0, playtime.cdmsf_sec0, playtime.cdmsf_frame0, playtime.cdmsf_min1, playtime.cdmsf_sec1, playtime.cdmsf_frame1); #endif /* Verifies if it is paused first... and if it is, unpause before stopping it. */ msp.hwndCallback = (HWND)NULL; /* None */ msp.ulReturn = (ULONG)NULL; /* We want this information */ msp.ulItem = MCI_STATUS_MODE; msp.ulValue = (ULONG)NULL; /* No additional information */ if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) == MCIERR_SUCCESS) { if (msp.ulReturn == MCI_MODE_PAUSE) { mgp.hwndCallback = (HWND)NULL; // None mciSendCommand(cdrom->id,MCI_RESUME,0,&mgp, 0); } } /* Now play it. */ mpp.hwndCallback = (HWND)NULL; // We do not want the info. temp if (LOUSHORT(mciSendCommand(cdrom->id,MCI_PLAY,MCI_FROM | MCI_TO,&mpp, 0)) == MCIERR_SUCCESS) return 0; return (CD_ERROR); } /* Pause play - Ready for MCI */ static int SDL_SYS_CDPause(SDL_CD *cdrom) { MCI_GENERIC_PARMS mgp; mgp.hwndCallback = (HWND)NULL; // None if (LOUSHORT(mciSendCommand(cdrom->id,MCI_PAUSE,MCI_WAIT,&mgp, 0)) == MCIERR_SUCCESS) return 0; return(CD_ERROR); } /* Resume play - Ready for MCI */ static int SDL_SYS_CDResume(SDL_CD *cdrom) { MCI_GENERIC_PARMS mgp; mgp.hwndCallback = (HWND)NULL; // None if (LOUSHORT(mciSendCommand(cdrom->id,MCI_RESUME,MCI_WAIT,&mgp, 0)) == MCIERR_SUCCESS) return 0; return(CD_ERROR); } /* Stop play - Ready for MCI */ static int SDL_SYS_CDStop(SDL_CD *cdrom) { MCI_GENERIC_PARMS mgp; MCI_STATUS_PARMS msp; /* Verifies if it is paused first... and if it is, unpause before stopping it. */ msp.hwndCallback = (HWND)NULL; /* None */ msp.ulReturn = (ULONG)NULL; /* We want this information */ msp.ulItem = MCI_STATUS_MODE; msp.ulValue = (ULONG)NULL; /* No additional information */ if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,&msp, 0)) == MCIERR_SUCCESS) { if (msp.ulReturn == MCI_MODE_PAUSE) { mgp.hwndCallback = (HWND)NULL; // None mciSendCommand(cdrom->id,MCI_RESUME,0,&mgp, 0); } } /* Now stops the media */ mgp.hwndCallback = (HWND)NULL; // None if (LOUSHORT(mciSendCommand(cdrom->id,MCI_STOP,MCI_WAIT,&mgp, 0)) == MCIERR_SUCCESS) return 0; return(CD_ERROR); } /* Eject the CD-ROM - Ready for MCI */ static int SDL_SYS_CDEject(SDL_CD *cdrom) { MCI_SET_PARMS msp; msp.hwndCallback = (HWND)NULL; // None msp.ulTimeFormat = (ULONG)NULL; // No change msp.ulSpeedFormat = (ULONG)NULL; // No change msp.ulAudio = (ULONG)NULL; // No Channel msp.ulLevel = (ULONG)NULL; // No Volume msp.ulOver = (ULONG)NULL; // No Delay msp.ulItem = (ULONG)NULL; // No item msp.ulValue = (ULONG)NULL; // No value for item flag if (LOUSHORT(mciSendCommand(cdrom->id,MCI_SET,MCI_WAIT | MCI_SET_DOOR_OPEN,&msp, 0)) == MCIERR_SUCCESS) return 0; return(CD_ERROR); } /* Close the CD-ROM handle - Ready for MCI */ static void SDL_SYS_CDClose(SDL_CD *cdrom) { MCI_GENERIC_PARMS mgp; mgp.hwndCallback = (HWND)NULL; // None mciSendCommand(cdrom->id,MCI_CLOSE,MCI_WAIT,&mgp, 0); } /* Finalize CDROM Subsystem - Ready for MCI */ void SDL_SYS_CDQuit(void) { int i; if ( SDL_numcds > 0 ) { for ( i=0; i<SDL_numcds; ++i ) { SDL_free(SDL_cdlist[i]); } SDL_numcds = 0; } } #endif /* SDL_CDROM_OS2 */