Mercurial > sdl-ios-xcode
annotate src/joystick/dummy/SDL_sysjoystick.c @ 4216:5b99971a27b4 SDL-1.2
Fixed bug #698
Hans de Goede 2009-02-13 01:10:52 PST
Since the new "glitch free" version of pulseaudio (used in Fedora 10 amongst
others), the sound of SDL using apps (like a simple playmus call) has been
crackling.
While looking in to fixing this I noticed that the current pulseaudio code in
SDL uses pa_simple. However pa_simple uses a thread to pump pulseaudio events
and ipc, given that SDL already has its own thread for audio handling this is
clearly suboptimal, leading to unnecessary context switching IPC, etc. Also
pa_simple does not allow one to implement the WaitAudio() callback for SDL
audiodrivers properly.
Given that my work is mostly a rewrite (although some original pieces remain)
I'm attaching the new .c and .h file, as that is easier to review then the huge
diff.
Let me know if you also want the diff.
This new version has the following features:
-no longer use an additional thread next to the SDL sound thread
-do not crackle with glitch free audio
-when used with a newer pulse, which does glitch free audio, the total latency
is
the same as with the alsa driver
-proper WaitAudio() implementation, saving another mixlen worth of latency
-adds a WaitDone() implementation
This patch has been written in consultancy with Lennart Poetering (the
pulseaudio author) and has been reviewed by him for correct use of the pa API.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 21 Sep 2009 09:27:08 +0000 |
| parents | a1b03ba2fcd0 |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 4159 | 3 Copyright (C) 1997-2009 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
|
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6 modify it under the terms of the GNU Lesser General Public |
| 0 | 7 License as published by the Free Software Foundation; either |
|
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8 version 2.1 of the License, or (at your option) any later version. |
| 0 | 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 | |
|
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13 Lesser General Public License for more details. |
| 0 | 14 |
|
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parents:
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15 You should have received a copy of the GNU Lesser General Public |
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Sam Lantinga <slouken@libsdl.org>
parents:
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16 License along with this library; if not, write to the Free Software |
|
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Sam Lantinga <slouken@libsdl.org>
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 0 | 18 |
| 19 Sam Lantinga | |
|
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20 slouken@libsdl.org |
| 0 | 21 */ |
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22 #include "SDL_config.h" |
| 0 | 23 |
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24 #if defined(SDL_JOYSTICK_DUMMY) || defined(SDL_JOYSTICK_DISABLED) |
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25 |
| 0 | 26 /* This is the system specific header for the SDL joystick API */ |
| 27 | |
| 28 #include "SDL_joystick.h" | |
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29 #include "../SDL_sysjoystick.h" |
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30 #include "../SDL_joystick_c.h" |
| 0 | 31 |
| 32 /* Function to scan the system for joysticks. | |
| 33 * This function should set SDL_numjoysticks to the number of available | |
| 34 * joysticks. Joystick 0 should be the system default joystick. | |
| 35 * It should return 0, or -1 on an unrecoverable fatal error. | |
| 36 */ | |
| 37 int SDL_SYS_JoystickInit(void) | |
| 38 { | |
| 39 SDL_numjoysticks = 0; | |
| 40 return(0); | |
| 41 } | |
| 42 | |
| 43 /* Function to get the device-dependent name of a joystick */ | |
| 44 const char *SDL_SYS_JoystickName(int index) | |
| 45 { | |
| 46 SDL_SetError("Logic error: No joysticks available"); | |
| 47 return(NULL); | |
| 48 } | |
| 49 | |
| 50 /* Function to open a joystick for use. | |
| 51 The joystick to open is specified by the index field of the joystick. | |
| 52 This should fill the nbuttons and naxes fields of the joystick structure. | |
| 53 It returns 0, or -1 if there is an error. | |
| 54 */ | |
| 55 int SDL_SYS_JoystickOpen(SDL_Joystick *joystick) | |
| 56 { | |
| 57 SDL_SetError("Logic error: No joysticks available"); | |
| 58 return(-1); | |
| 59 } | |
| 60 | |
| 61 /* Function to update the state of a joystick - called as a device poll. | |
| 62 * This function shouldn't update the joystick structure directly, | |
| 63 * but instead should call SDL_PrivateJoystick*() to deliver events | |
| 64 * and update joystick device state. | |
| 65 */ | |
| 66 void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick) | |
| 67 { | |
| 68 return; | |
| 69 } | |
| 70 | |
| 71 /* Function to close a joystick after use */ | |
| 72 void SDL_SYS_JoystickClose(SDL_Joystick *joystick) | |
| 73 { | |
| 74 return; | |
| 75 } | |
| 76 | |
| 77 /* Function to perform any system-specific joystick related cleanup */ | |
| 78 void SDL_SYS_JoystickQuit(void) | |
| 79 { | |
| 80 return; | |
| 81 } | |
| 82 | |
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83 #endif /* SDL_JOYSTICK_DUMMY || SDL_JOYSTICK_DISABLED */ |