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authorChris Robinson <[email protected]>2008-12-07 01:05:39 -0800
committerChris Robinson <[email protected]>2008-12-07 01:05:39 -0800
commit8b54d59b8c201c90da4ec45bf81d7a945b143d10 (patch)
tree2220615745b345427f96274a91fd56c31527653f /Alc
parentf6a4dbabdda352385073bf5cf404a0c8e29da918 (diff)
Add an SDL backend
Diffstat (limited to 'Alc')
-rw-r--r--Alc/ALc.c3
-rw-r--r--Alc/sdl.c306
2 files changed, 309 insertions, 0 deletions
diff --git a/Alc/ALc.c b/Alc/ALc.c
index 13e2662c..925e4867 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -67,6 +67,9 @@ static struct {
#ifdef HAVE_WINMM
{ "winmm", alcWinMMInit, EmptyFuncs },
#endif
+#ifdef HAVE_SDL
+ { "sdl", alc_sdl_init, EmptyFuncs },
+#endif
{ "wave", alc_wave_init, EmptyFuncs },
diff --git a/Alc/sdl.c b/Alc/sdl.c
new file mode 100644
index 00000000..791763ba
--- /dev/null
+++ b/Alc/sdl.c
@@ -0,0 +1,306 @@
+/**
+ * OpenAL cross platform audio library
+ * Copyright (C) 1999-2007 by authors.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ * Or go to http://www.gnu.org/copyleft/lgpl.html
+ */
+
+#include "config.h"
+
+#include "alMain.h"
+#include "AL/al.h"
+#include "AL/alc.h"
+
+#include <string.h>
+#include <stdlib.h>
+#ifdef HAVE_DLFCN_H
+#include <dlfcn.h>
+#endif
+
+#include <SDL/SDL.h>
+
+static void *sdl_handle;
+#define MAKE_FUNC(x) static typeof(x) * p##x
+MAKE_FUNC(SDL_PauseAudio);
+MAKE_FUNC(SDL_CloseAudio);
+MAKE_FUNC(SDL_OpenAudio);
+MAKE_FUNC(SDL_InitSubSystem);
+MAKE_FUNC(SDL_GetError);
+MAKE_FUNC(SDL_LockAudio);
+MAKE_FUNC(SDL_UnlockAudio);
+#undef MAKE_FUNC
+
+static char *sdl_device;
+/* SDL audio can only be initialized once per process */
+static int initialized;
+
+typedef struct {
+ SDL_AudioSpec audioSpec;
+ volatile int killNow;
+ ALvoid *thread;
+
+ ALubyte *mix_data;
+ int data_size;
+ int data_read;
+ int data_write;
+} sdl_data;
+
+
+static void SDLCALL fillAudio(void *userdata, Uint8 *stream, int len)
+{
+ sdl_data *data = (sdl_data*)userdata;
+ int rem = data->data_size-data->data_read;
+ if(len >= rem)
+ {
+ memcpy(stream, data->mix_data + data->data_read, rem);
+ stream += rem;
+ len -= rem;
+ data->data_read = 0;
+ }
+ if(len > 0)
+ {
+ memcpy(stream, data->mix_data + data->data_read, len);
+ data->data_read += len;
+ }
+}
+
+static ALuint SDLProc(ALvoid *ptr)
+{
+ ALCdevice *pDevice = (ALCdevice*)ptr;
+ sdl_data *data = (sdl_data*)pDevice->ExtraData;
+ int len, rem;
+
+ pSDL_PauseAudio(0);
+ while(!data->killNow)
+ {
+ pSDL_LockAudio();
+
+ len = (data->data_read-data->data_write+data->data_size)%data->data_size;
+ if(len == 0)
+ {
+ pSDL_UnlockAudio();
+
+ Sleep(1);
+ continue;
+ }
+
+ rem = data->data_size - data->data_write;
+
+ SuspendContext(NULL);
+ if(len > rem)
+ {
+ aluMixData(pDevice->Context, data->mix_data+data->data_write, rem, pDevice->Format);
+ aluMixData(pDevice->Context, data->mix_data, len-rem, pDevice->Format);
+ }
+ else
+ aluMixData(pDevice->Context, data->mix_data+data->data_write, len, pDevice->Format);
+ ProcessContext(NULL);
+
+ data->data_write = data->data_read;
+
+ pSDL_UnlockAudio();
+ }
+ pSDL_PauseAudio(1);
+
+ return 0;
+}
+
+static ALCboolean sdl_open_playback(ALCdevice *device, const ALCchar *deviceName)
+{
+ SDL_AudioSpec sdlSpec;
+ ALuint frameSize;
+ sdl_data *data;
+
+ if(initialized || !sdl_device)
+ return ALC_FALSE;
+
+ if(deviceName)
+ {
+ if(strcmp(deviceName, sdl_device))
+ return ALC_FALSE;
+ device->szDeviceName = sdl_device;
+ }
+ else
+ device->szDeviceName = sdl_device;
+
+ data = (sdl_data*)calloc(1, sizeof(sdl_data));
+ data->killNow = 0;
+
+ frameSize = aluBytesFromFormat(device->Format) *
+ aluChannelsFromFormat(device->Format);
+
+ sdlSpec.freq = device->Frequency;
+ sdlSpec.channels = aluChannelsFromFormat(device->Format);
+ switch(aluBytesFromFormat(device->Format))
+ {
+ case 1:
+ sdlSpec.format = AUDIO_U8;
+ break;
+ case 2:
+ sdlSpec.format = AUDIO_S16SYS;
+ break;
+ default:
+ AL_PRINT("Unknown format?! %x\n", device->Format);
+ free(data);
+ return ALC_FALSE;
+ }
+ sdlSpec.samples = 1;
+ while(sdlSpec.samples < device->UpdateSize)
+ sdlSpec.samples <<= 1;
+ sdlSpec.samples >>= 1;
+
+ sdlSpec.callback = fillAudio;
+ sdlSpec.userdata = data;
+
+ if(pSDL_OpenAudio(&sdlSpec, &data->audioSpec) < 0)
+ {
+ AL_PRINT("Audio init failed: %s\n", pSDL_GetError());
+ free(data);
+ return ALC_FALSE;
+ }
+
+ if(!((data->audioSpec.format == AUDIO_U8 && aluBytesFromFormat(device->Format) == 1) ||
+ (data->audioSpec.format == AUDIO_S16SYS && aluBytesFromFormat(device->Format) == 2)))
+ {
+ AL_PRINT("Could not set %d-bit, got format %#x instead\n", aluBytesFromFormat(device->Format), data->audioSpec.format);
+ pSDL_CloseAudio();
+ free(data);
+ return ALC_FALSE;
+ }
+ if(aluChannelsFromFormat(device->Format) != data->audioSpec.channels)
+ {
+ AL_PRINT("Could not set %d channels, got %d instead\n", aluChannelsFromFormat(device->Format), data->audioSpec.channels);
+ pSDL_CloseAudio();
+ free(data);
+ return ALC_FALSE;
+ }
+
+ device->Frequency = data->audioSpec.freq;
+ device->UpdateSize = data->audioSpec.size / frameSize;
+
+ data->data_size = device->UpdateSize * frameSize * 2;
+ data->mix_data = malloc(data->data_size);
+ if(data->mix_data == NULL)
+ {
+ AL_PRINT("Could not allocate %d bytes\n", data->data_size);
+ pSDL_CloseAudio();
+ free(data);
+ return ALC_FALSE;
+ }
+ memset(data->mix_data, data->audioSpec.silence, data->data_size);
+
+ device->ExtraData = data;
+ data->thread = StartThread(SDLProc, device);
+ if(data->thread == NULL)
+ {
+ pSDL_CloseAudio();
+ device->ExtraData = NULL;
+ free(data->mix_data);
+ free(data);
+ return ALC_FALSE;
+ }
+
+ initialized = 1;
+
+ return ALC_TRUE;
+}
+
+static void sdl_close_playback(ALCdevice *device)
+{
+ sdl_data *data = (sdl_data*)device->ExtraData;
+ data->killNow = 1;
+ StopThread(data->thread);
+
+ pSDL_CloseAudio();
+ initialized = 0;
+
+ free(data->mix_data);
+ free(data);
+ device->ExtraData = NULL;
+}
+
+
+static ALCboolean sdl_open_capture(ALCdevice *device, const ALCchar *deviceName, ALCuint frequency, ALCenum format, ALCsizei SampleSize)
+{
+ return ALC_FALSE;
+ (void)device;
+ (void)deviceName;
+ (void)frequency;
+ (void)format;
+ (void)SampleSize;
+}
+
+
+BackendFuncs sdl_funcs = {
+ sdl_open_playback,
+ sdl_close_playback,
+ sdl_open_capture,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ NULL
+};
+
+void alc_sdl_init(BackendFuncs *func_list)
+{
+ const char *str;
+
+ *func_list = sdl_funcs;
+
+#ifdef HAVE_DLFCN_H
+#if defined(__APPLE__) && defined(__MACH__)
+# define SDLLIB "SDL.framework/SDL"
+#else
+# define SDLLIB "libSDL.so"
+#endif
+ sdl_handle = dlopen(SDLLIB, RTLD_NOW);
+ if(!sdl_handle)
+ return;
+ dlerror();
+
+#define LOAD_FUNC(f) do { \
+ p##f = (typeof(f)*)dlsym(sdl_handle, #f); \
+ if((str=dlerror()) != NULL) \
+ { \
+ dlclose(sdl_handle); \
+ sdl_handle = NULL; \
+ AL_PRINT("Could not load %s from "SDLLIB": %s\n", #f, str); \
+ return; \
+ } \
+} while(0)
+#else
+ str = NULL;
+ sdl_handle = 0xDEADBEEF;
+#define LOAD_FUNC(f) p##f = f
+#endif
+
+ LOAD_FUNC(SDL_PauseAudio);
+ LOAD_FUNC(SDL_CloseAudio);
+ LOAD_FUNC(SDL_OpenAudio);
+ LOAD_FUNC(SDL_InitSubSystem);
+ LOAD_FUNC(SDL_GetError);
+ LOAD_FUNC(SDL_LockAudio);
+ LOAD_FUNC(SDL_UnlockAudio);
+
+#undef LOAD_FUNC
+
+ if(pSDL_InitSubSystem(SDL_INIT_AUDIO) < 0)
+ return;
+
+ sdl_device = AppendDeviceList("SDL Software");
+ AppendAllDeviceList(sdl_device);
+}