Fix engine not starting on Windows if linked against SDL > 2.0.5
[xonotic/darkplaces.git] / snd_sdl.c
1 /*
2 Copyright (C) 2004 Andreas Kirsch
3
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License
6 as published by the Free Software Foundation; either version 2
7 of the License, or (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12
13 See the GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
18 */
19 #include <math.h>
20 #include <SDL.h>
21
22 #include "quakedef.h"
23
24 #include "snd_main.h"
25
26
27 static unsigned int sdlaudiotime = 0;
28 static int audio_device = 0;
29
30
31 // Note: SDL calls SDL_LockAudio() right before this function, so no need to lock the audio data here
32 static void Buffer_Callback (void *userdata, Uint8 *stream, int len)
33 {
34         unsigned int factor, RequestedFrames, MaxFrames, FrameCount;
35         unsigned int StartOffset, EndOffset;
36
37         factor = snd_renderbuffer->format.channels * snd_renderbuffer->format.width;
38         if ((unsigned int)len % factor != 0)
39                 Sys_Error("SDL sound: invalid buffer length passed to Buffer_Callback (%d bytes)\n", len);
40
41         RequestedFrames = (unsigned int)len / factor;
42
43         if (SndSys_LockRenderBuffer())
44         {
45                 if (snd_usethreadedmixing)
46                 {
47                         S_MixToBuffer(stream, RequestedFrames);
48                         if (snd_blocked)
49                                 memset(stream, snd_renderbuffer->format.width == 1 ? 0x80 : 0, len);
50                         SndSys_UnlockRenderBuffer();
51                         return;
52                 }
53
54                 // Transfert up to a chunk of samples from snd_renderbuffer to stream
55                 MaxFrames = snd_renderbuffer->endframe - snd_renderbuffer->startframe;
56                 if (MaxFrames > RequestedFrames)
57                         FrameCount = RequestedFrames;
58                 else
59                         FrameCount = MaxFrames;
60                 StartOffset = snd_renderbuffer->startframe % snd_renderbuffer->maxframes;
61                 EndOffset = (snd_renderbuffer->startframe + FrameCount) % snd_renderbuffer->maxframes;
62                 if (StartOffset > EndOffset)  // if the buffer wraps
63                 {
64                         unsigned int PartialLength1, PartialLength2;
65
66                         PartialLength1 = (snd_renderbuffer->maxframes - StartOffset) * factor;
67                         memcpy(stream, &snd_renderbuffer->ring[StartOffset * factor], PartialLength1);
68
69                         PartialLength2 = FrameCount * factor - PartialLength1;
70                         memcpy(&stream[PartialLength1], &snd_renderbuffer->ring[0], PartialLength2);
71                 }
72                 else
73                         memcpy(stream, &snd_renderbuffer->ring[StartOffset * factor], FrameCount * factor);
74
75                 snd_renderbuffer->startframe += FrameCount;
76
77                 if (FrameCount < RequestedFrames && developer_insane.integer && vid_activewindow)
78                         Con_DPrintf("SDL sound: %u sample frames missing\n", RequestedFrames - FrameCount);
79
80                 sdlaudiotime += RequestedFrames;
81
82                 SndSys_UnlockRenderBuffer();
83         }
84 }
85
86
87 /*
88 ====================
89 SndSys_Init
90
91 Create "snd_renderbuffer" with the proper sound format if the call is successful
92 May return a suggested format if the requested format isn't available
93 ====================
94 */
95 qboolean SndSys_Init (const snd_format_t* requested, snd_format_t* suggested)
96 {
97         unsigned int buffersize;
98         SDL_AudioSpec wantspec;
99         SDL_AudioSpec obtainspec;
100
101         snd_threaded = false;
102
103         Con_DPrint ("SndSys_Init: using the SDL module\n");
104
105         // Init the SDL Audio subsystem
106         if( SDL_InitSubSystem( SDL_INIT_AUDIO ) ) {
107                 Con_Print( "Initializing the SDL Audio subsystem failed!\n" );
108                 return false;
109         }
110
111         buffersize = (unsigned int)ceil((double)requested->speed / 25.0); // 2048 bytes on 24kHz to 48kHz
112
113         // Init the SDL Audio subsystem
114         wantspec.callback = Buffer_Callback;
115         wantspec.userdata = NULL;
116         wantspec.freq = requested->speed;
117         wantspec.format = ((requested->width == 1) ? AUDIO_U8 : AUDIO_S16SYS);
118         wantspec.channels = requested->channels;
119         wantspec.samples = CeilPowerOf2(buffersize);  // needs to be a power of 2 on some platforms.
120
121         Con_Printf("Wanted audio Specification:\n"
122                                 "\tChannels  : %i\n"
123                                 "\tFormat    : 0x%X\n"
124                                 "\tFrequency : %i\n"
125                                 "\tSamples   : %i\n",
126                                 wantspec.channels, wantspec.format, wantspec.freq, wantspec.samples);
127
128         if ((audio_device = SDL_OpenAudioDevice(NULL, 0, &wantspec, &obtainspec, 0)) == 0)
129         {
130                 Con_Printf( "Failed to open the audio device! (%s)\n", SDL_GetError() );
131                 return false;
132         }
133
134         Con_Printf("Obtained audio specification:\n"
135                                 "\tChannels  : %i\n"
136                                 "\tFormat    : 0x%X\n"
137                                 "\tFrequency : %i\n"
138                                 "\tSamples   : %i\n",
139                                 obtainspec.channels, obtainspec.format, obtainspec.freq, obtainspec.samples);
140
141         // If we haven't obtained what we wanted
142         if (wantspec.freq != obtainspec.freq ||
143                 wantspec.format != obtainspec.format ||
144                 wantspec.channels != obtainspec.channels)
145         {
146                 SDL_CloseAudioDevice(audio_device);
147
148                 // Pass the obtained format as a suggested format
149                 if (suggested != NULL)
150                 {
151                         suggested->speed = obtainspec.freq;
152                         // FIXME: check the format more carefully. There are plenty of unsupported cases
153                         suggested->width = ((obtainspec.format == AUDIO_U8) ? 1 : 2);
154                         suggested->channels = obtainspec.channels;
155                 }
156
157                 return false;
158         }
159
160         snd_threaded = true;
161
162         snd_renderbuffer = Snd_CreateRingBuffer(requested, 0, NULL);
163         if (snd_channellayout.integer == SND_CHANNELLAYOUT_AUTO)
164                 Cvar_SetValueQuick (&snd_channellayout, SND_CHANNELLAYOUT_STANDARD);
165
166         sdlaudiotime = 0;
167         SDL_PauseAudioDevice(audio_device, 0);
168
169         return true;
170 }
171
172
173 /*
174 ====================
175 SndSys_Shutdown
176
177 Stop the sound card, delete "snd_renderbuffer" and free its other resources
178 ====================
179 */
180 void SndSys_Shutdown(void)
181 {
182         if (audio_device > 0) {
183                 SDL_CloseAudioDevice(audio_device);
184                 audio_device = 0;
185         }
186         if (snd_renderbuffer != NULL)
187         {
188                 Mem_Free(snd_renderbuffer->ring);
189                 Mem_Free(snd_renderbuffer);
190                 snd_renderbuffer = NULL;
191         }
192 }
193
194
195 /*
196 ====================
197 SndSys_Submit
198
199 Submit the contents of "snd_renderbuffer" to the sound card
200 ====================
201 */
202 void SndSys_Submit (void)
203 {
204         // Nothing to do here (this sound module is callback-based)
205 }
206
207
208 /*
209 ====================
210 SndSys_GetSoundTime
211
212 Returns the number of sample frames consumed since the sound started
213 ====================
214 */
215 unsigned int SndSys_GetSoundTime (void)
216 {
217         return sdlaudiotime;
218 }
219
220
221 /*
222 ====================
223 SndSys_LockRenderBuffer
224
225 Get the exclusive lock on "snd_renderbuffer"
226 ====================
227 */
228 qboolean SndSys_LockRenderBuffer (void)
229 {
230         SDL_LockAudioDevice(audio_device);
231         return true;
232 }
233
234
235 /*
236 ====================
237 SndSys_UnlockRenderBuffer
238
239 Release the exclusive lock on "snd_renderbuffer"
240 ====================
241 */
242 void SndSys_UnlockRenderBuffer (void)
243 {
244         SDL_UnlockAudioDevice(audio_device);
245 }
246
247 /*
248 ====================
249 SndSys_SendKeyEvents
250
251 Send keyboard events originating from the sound system (e.g. MIDI)
252 ====================
253 */
254 void SndSys_SendKeyEvents(void)
255 {
256         // not supported
257 }