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1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2004 Sam Lantinga |
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4 |
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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 Library General Public |
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7 License as published by the Free Software Foundation; either |
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8 version 2 of the License, or (at your option) any later version. |
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9 |
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10 This library is distributed in the hope that it will be useful, |
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 Library General Public License for more details. |
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14 |
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15 You should have received a copy of the GNU Library General Public |
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16 License along with this library; if not, write to the Free |
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17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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18 |
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19 Sam Lantinga |
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20 slouken@libsdl.org |
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21 */ |
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22 #include "SDL_config.h" |
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23 |
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24 /* |
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25 Audio interrupt variables and callback function |
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26 |
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27 Patrice Mandin |
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28 */ |
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29 |
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30 #include <unistd.h> |
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31 |
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32 #include <mint/osbind.h> |
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33 #include <mint/falcon.h> |
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34 #include <mint/mintbind.h> |
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35 #include <mint/cookie.h> |
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36 |
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37 #include "SDL_audio.h" |
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38 #include "SDL_mintaudio.h" |
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39 #include "SDL_mintaudio_stfa.h" |
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40 |
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41 /* The audio device */ |
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42 |
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43 SDL_AudioDevice *SDL_MintAudio_device; |
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44 Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */ |
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45 unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */ |
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46 volatile unsigned short SDL_MintAudio_numbuf; /* Buffer to play */ |
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47 volatile unsigned short SDL_MintAudio_mutex; |
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48 volatile unsigned long SDL_MintAudio_clocktics; |
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49 cookie_stfa_t *SDL_MintAudio_stfa; |
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50 unsigned short SDL_MintAudio_hasfpu; |
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51 |
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52 /* MiNT thread variables */ |
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53 SDL_bool SDL_MintAudio_mint_present; |
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54 SDL_bool SDL_MintAudio_quit_thread; |
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55 SDL_bool SDL_MintAudio_thread_finished; |
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56 long SDL_MintAudio_thread_pid; |
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57 |
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58 /* The callback function, called by each driver whenever needed */ |
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59 |
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60 void SDL_MintAudio_Callback(void) |
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61 { |
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62 Uint8 *buffer; |
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63 SDL_AudioDevice *audio = SDL_MintAudio_device; |
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64 |
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65 buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf]; |
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66 SDL_memset(buffer, audio->spec.silence, audio->spec.size); |
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67 |
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68 if (audio->paused) |
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69 return; |
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70 |
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71 if (audio->convert.needed) { |
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72 int silence; |
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73 |
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74 if ( audio->convert.src_format == AUDIO_U8 ) { |
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75 silence = 0x80; |
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76 } else { |
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77 silence = 0; |
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78 } |
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79 SDL_memset(audio->convert.buf, silence, audio->convert.len); |
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80 audio->spec.callback(audio->spec.userdata, |
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81 (Uint8 *)audio->convert.buf,audio->convert.len); |
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82 SDL_ConvertAudio(&audio->convert); |
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83 SDL_memcpy(buffer, audio->convert.buf, audio->convert.len_cvt); |
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84 } else { |
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85 audio->spec.callback(audio->spec.userdata, buffer, audio->spec.size); |
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86 } |
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87 } |
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88 |
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89 /* Add a new frequency/clock/predivisor to the current list */ |
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90 void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock, |
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91 Uint32 prediv, int gpio_bits) |
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92 { |
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93 int i, p; |
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94 |
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95 if (MINTAUDIO_freqcount==MINTAUDIO_maxfreqs) { |
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96 return; |
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97 } |
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98 |
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99 /* Search where to insert the frequency (highest first) */ |
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100 for (p=0; p<MINTAUDIO_freqcount; p++) { |
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101 if (frequency > MINTAUDIO_frequencies[p].frequency) { |
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102 break; |
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103 } |
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104 } |
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105 |
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106 /* Put all following ones farer */ |
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107 if (MINTAUDIO_freqcount>0) { |
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108 for (i=MINTAUDIO_freqcount; i>p; i--) { |
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109 SDL_memcpy(&MINTAUDIO_frequencies[i], &MINTAUDIO_frequencies[i-1], sizeof(mint_frequency_t)); |
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110 } |
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111 } |
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112 |
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113 /* And insert new one */ |
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114 MINTAUDIO_frequencies[p].frequency = frequency; |
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115 MINTAUDIO_frequencies[p].masterclock = clock; |
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116 MINTAUDIO_frequencies[p].predivisor = prediv; |
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117 MINTAUDIO_frequencies[p].gpio_bits = gpio_bits; |
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118 |
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119 MINTAUDIO_freqcount++; |
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120 } |
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121 |
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122 /* Search for the nearest frequency */ |
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123 int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq) |
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124 { |
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125 int i; |
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126 |
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127 /* Only 1 freq ? */ |
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128 if (MINTAUDIO_freqcount==1) { |
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129 return 0; |
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130 } |
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131 |
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132 /* Check the array */ |
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133 for (i=0; i<MINTAUDIO_freqcount; i++) { |
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134 if (desired_freq >= ((MINTAUDIO_frequencies[i].frequency+ |
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135 MINTAUDIO_frequencies[i+1].frequency)>>1)) { |
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136 return i; |
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137 } |
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138 } |
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139 |
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140 /* Not in the array, give the latest */ |
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141 return MINTAUDIO_freqcount-1; |
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142 } |
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143 |
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144 /* Check if FPU is present */ |
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145 void SDL_MintAudio_CheckFpu(void) |
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146 { |
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147 unsigned long cookie_fpu; |
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148 |
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149 SDL_MintAudio_hasfpu = 0; |
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150 if (Getcookie(C__FPU, &cookie_fpu) != C_FOUND) { |
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151 return; |
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152 } |
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153 switch ((cookie_fpu>>16)&0xfffe) { |
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154 case 2: |
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155 case 4: |
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156 case 6: |
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157 case 8: |
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158 case 16: |
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159 SDL_MintAudio_hasfpu = 1; |
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160 break; |
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161 } |
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162 } |
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163 |
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164 /* The thread function, used under MiNT with xbios */ |
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165 int SDL_MintAudio_Thread(long param) |
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166 { |
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167 SndBufPtr pointers; |
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168 SDL_bool buffers_filled[2] = {SDL_FALSE, SDL_FALSE}; |
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169 |
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170 SDL_MintAudio_thread_finished = SDL_FALSE; |
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171 while (!SDL_MintAudio_quit_thread) { |
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172 if (Buffptr(&pointers)!=0) |
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173 continue; |
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174 |
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175 if (( (unsigned long)pointers.play>=(unsigned long)SDL_MintAudio_audiobuf[0]) |
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176 && ( (unsigned long)pointers.play<=(unsigned long)SDL_MintAudio_audiobuf[1])) |
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177 { |
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178 /* DMA is reading buffer #0, setup buffer #1 if not already done */ |
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179 if (!buffers_filled[1]) { |
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180 SDL_MintAudio_numbuf = 1; |
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181 SDL_MintAudio_Callback(); |
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182 Setbuffer(0, SDL_MintAudio_audiobuf[1], SDL_MintAudio_audiobuf[1] + SDL_MintAudio_audiosize); |
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183 buffers_filled[1]=SDL_TRUE; |
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184 buffers_filled[0]=SDL_FALSE; |
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185 } |
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186 } else { |
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187 /* DMA is reading buffer #1, setup buffer #0 if not already done */ |
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188 if (!buffers_filled[0]) { |
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189 SDL_MintAudio_numbuf = 0; |
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190 SDL_MintAudio_Callback(); |
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191 Setbuffer(0, SDL_MintAudio_audiobuf[0], SDL_MintAudio_audiobuf[0] + SDL_MintAudio_audiosize); |
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192 buffers_filled[0]=SDL_TRUE; |
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193 buffers_filled[1]=SDL_FALSE; |
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194 } |
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195 } |
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196 |
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197 usleep(100); |
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198 } |
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199 SDL_MintAudio_thread_finished = SDL_TRUE; |
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200 return 0; |
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201 } |
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202 |
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203 void SDL_MintAudio_WaitThread(void) |
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204 { |
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205 if (!SDL_MintAudio_mint_present) |
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206 return; |
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207 |
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208 if (SDL_MintAudio_thread_finished) |
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209 return; |
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210 |
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211 SDL_MintAudio_quit_thread = SDL_TRUE; |
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212 while (!SDL_MintAudio_thread_finished) { |
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213 Syield(); |
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214 } |
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215 } |