e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 Sam Lantinga |
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 |
20 | slouken@libsdl.org |
21 | */ |
22 | #include "SDL_config.h" |
23 | |
24 | /* |
25 | Audio interrupt variables and callback function |
26 | |
27 | Patrice Mandin |
28 | */ |
29 | |
30 | #include <unistd.h> |
31 | |
32 | #include <mint/osbind.h> |
33 | #include <mint/falcon.h> |
34 | #include <mint/mintbind.h> |
35 | #include <mint/cookie.h> |
36 | |
37 | #include "SDL_audio.h" |
38 | #include "SDL_mintaudio.h" |
39 | #include "SDL_mintaudio_stfa.h" |
40 | |
41 | /* The audio device */ |
42 | |
43 | SDL_AudioDevice *SDL_MintAudio_device; |
44 | Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */ |
45 | unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */ |
46 | volatile unsigned short SDL_MintAudio_numbuf; /* Buffer to play */ |
47 | volatile unsigned short SDL_MintAudio_mutex; |
48 | volatile unsigned long SDL_MintAudio_clocktics; |
49 | cookie_stfa_t *SDL_MintAudio_stfa; |
50 | unsigned short SDL_MintAudio_hasfpu; |
51 | |
52 | /* MiNT thread variables */ |
53 | SDL_bool SDL_MintAudio_mint_present; |
54 | SDL_bool SDL_MintAudio_quit_thread; |
55 | SDL_bool SDL_MintAudio_thread_finished; |
56 | long SDL_MintAudio_thread_pid; |
57 | |
58 | /* The callback function, called by each driver whenever needed */ |
59 | |
60 | void SDL_MintAudio_Callback(void) |
61 | { |
62 | Uint8 *buffer; |
63 | SDL_AudioDevice *audio = SDL_MintAudio_device; |
64 | |
65 | buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf]; |
66 | SDL_memset(buffer, audio->spec.silence, audio->spec.size); |
67 | |
68 | if (audio->paused) |
69 | return; |
70 | |
71 | if (audio->convert.needed) { |
72 | int silence; |
73 | |
74 | if ( audio->convert.src_format == AUDIO_U8 ) { |
75 | silence = 0x80; |
76 | } else { |
77 | silence = 0; |
78 | } |
79 | SDL_memset(audio->convert.buf, silence, audio->convert.len); |
80 | audio->spec.callback(audio->spec.userdata, |
81 | (Uint8 *)audio->convert.buf,audio->convert.len); |
82 | SDL_ConvertAudio(&audio->convert); |
83 | SDL_memcpy(buffer, audio->convert.buf, audio->convert.len_cvt); |
84 | } else { |
85 | audio->spec.callback(audio->spec.userdata, buffer, audio->spec.size); |
86 | } |
87 | } |
88 | |
89 | /* Add a new frequency/clock/predivisor to the current list */ |
90 | void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock, |
91 | Uint32 prediv, int gpio_bits) |
92 | { |
93 | int i, p; |
94 | |
95 | if (MINTAUDIO_freqcount==MINTAUDIO_maxfreqs) { |
96 | return; |
97 | } |
98 | |
99 | /* Search where to insert the frequency (highest first) */ |
100 | for (p=0; p<MINTAUDIO_freqcount; p++) { |
101 | if (frequency > MINTAUDIO_frequencies[p].frequency) { |
102 | break; |
103 | } |
104 | } |
105 | |
106 | /* Put all following ones farer */ |
107 | if (MINTAUDIO_freqcount>0) { |
108 | for (i=MINTAUDIO_freqcount; i>p; i--) { |
109 | SDL_memcpy(&MINTAUDIO_frequencies[i], &MINTAUDIO_frequencies[i-1], sizeof(mint_frequency_t)); |
110 | } |
111 | } |
112 | |
113 | /* And insert new one */ |
114 | MINTAUDIO_frequencies[p].frequency = frequency; |
115 | MINTAUDIO_frequencies[p].masterclock = clock; |
116 | MINTAUDIO_frequencies[p].predivisor = prediv; |
117 | MINTAUDIO_frequencies[p].gpio_bits = gpio_bits; |
118 | |
119 | MINTAUDIO_freqcount++; |
120 | } |
121 | |
122 | /* Search for the nearest frequency */ |
123 | int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq) |
124 | { |
125 | int i; |
126 | |
127 | /* Only 1 freq ? */ |
128 | if (MINTAUDIO_freqcount==1) { |
129 | return 0; |
130 | } |
131 | |
132 | /* Check the array */ |
133 | for (i=0; i<MINTAUDIO_freqcount; i++) { |
134 | if (desired_freq >= ((MINTAUDIO_frequencies[i].frequency+ |
135 | MINTAUDIO_frequencies[i+1].frequency)>>1)) { |
136 | return i; |
137 | } |
138 | } |
139 | |
140 | /* Not in the array, give the latest */ |
141 | return MINTAUDIO_freqcount-1; |
142 | } |
143 | |
144 | /* Check if FPU is present */ |
145 | void SDL_MintAudio_CheckFpu(void) |
146 | { |
147 | unsigned long cookie_fpu; |
148 | |
149 | SDL_MintAudio_hasfpu = 0; |
150 | if (Getcookie(C__FPU, &cookie_fpu) != C_FOUND) { |
151 | return; |
152 | } |
153 | switch ((cookie_fpu>>16)&0xfffe) { |
154 | case 2: |
155 | case 4: |
156 | case 6: |
157 | case 8: |
158 | case 16: |
159 | SDL_MintAudio_hasfpu = 1; |
160 | break; |
161 | } |
162 | } |
163 | |
164 | /* The thread function, used under MiNT with xbios */ |
165 | int SDL_MintAudio_Thread(long param) |
166 | { |
167 | SndBufPtr pointers; |
168 | SDL_bool buffers_filled[2] = {SDL_FALSE, SDL_FALSE}; |
169 | |
170 | SDL_MintAudio_thread_finished = SDL_FALSE; |
171 | while (!SDL_MintAudio_quit_thread) { |
172 | if (Buffptr(&pointers)!=0) |
173 | continue; |
174 | |
175 | if (( (unsigned long)pointers.play>=(unsigned long)SDL_MintAudio_audiobuf[0]) |
176 | && ( (unsigned long)pointers.play<=(unsigned long)SDL_MintAudio_audiobuf[1])) |
177 | { |
178 | /* DMA is reading buffer #0, setup buffer #1 if not already done */ |
179 | if (!buffers_filled[1]) { |
180 | SDL_MintAudio_numbuf = 1; |
181 | SDL_MintAudio_Callback(); |
182 | Setbuffer(0, SDL_MintAudio_audiobuf[1], SDL_MintAudio_audiobuf[1] + SDL_MintAudio_audiosize); |
183 | buffers_filled[1]=SDL_TRUE; |
184 | buffers_filled[0]=SDL_FALSE; |
185 | } |
186 | } else { |
187 | /* DMA is reading buffer #1, setup buffer #0 if not already done */ |
188 | if (!buffers_filled[0]) { |
189 | SDL_MintAudio_numbuf = 0; |
190 | SDL_MintAudio_Callback(); |
191 | Setbuffer(0, SDL_MintAudio_audiobuf[0], SDL_MintAudio_audiobuf[0] + SDL_MintAudio_audiosize); |
192 | buffers_filled[0]=SDL_TRUE; |
193 | buffers_filled[1]=SDL_FALSE; |
194 | } |
195 | } |
196 | |
197 | usleep(100); |
198 | } |
199 | SDL_MintAudio_thread_finished = SDL_TRUE; |
200 | return 0; |
201 | } |
202 | |
203 | void SDL_MintAudio_WaitThread(void) |
204 | { |
205 | if (!SDL_MintAudio_mint_present) |
206 | return; |
207 | |
208 | if (SDL_MintAudio_thread_finished) |
209 | return; |
210 | |
211 | SDL_MintAudio_quit_thread = SDL_TRUE; |
212 | while (!SDL_MintAudio_thread_finished) { |
213 | Syield(); |
214 | } |
215 | } |