Shamusworld >> Repos - thunder/blob - src/sound.cpp

   1 //
   2 // Sound Handler
   3 //
   4 // by James Hammons
   5 // (C) 2014 Underground Software
   6 //
   7 // JLH = James Hammons <jlhamm@acm.org>
   8 //
   9 // Who  When        What
  10 // ---  ----------  -----------------------------------------------------------
  11 // JLH  04/18/2014  Created this file
  12 //
  13
  14 #include "sound.h"
  15 #include <SDL2/SDL.h>
  16 #include "resource.h"
  17
  18 // Function prototypes
  19 void SoundFunc(void *, Uint8 *, int);
  20
  21 // Vars
  22 extern uint8_t voice_rom[];                     // PCM data pointer
  23
  24 static bool soundInitialized = false;
  25 const float sampleBase = 22050.0/6000.0;  // Btwn 5512.5 and 6000
  26 bool snd_go = false;
  27 bool chan1_go = false, chan2_go = false, chan3_go = false;
  28 bool chan4_go = false, chan5_go = false, chan6_go = false;
  29 uint8_t * sndp1, * sndp2, * sndp3, * sndp4, * sndp5, * sndp6;
  30 uint32_t rom_pos, end_pos;
  31 uint32_t spos1, end_pos1;
  32 uint32_t spos2, end_pos2;
  33 uint32_t spos3, end_pos3;
  34 uint32_t spos4, end_pos4;
  35 uint32_t spos5, end_pos5;
  36 uint32_t spos6, end_pos6;
  37 float sample1;
  38 uint8_t prevSamp1;
  39 int8_t delta_x1;
  40 float sample2;
  41 uint8_t prevSamp2;
  42 int8_t delta_x2;
  43 uint16_t snd_num;
  44 uint8_t * snd_array[3] = { sunknown, scya, scamera }; // From RESOURCE.H
  45 uint32_t snd_lens[3]   = { sunknownlen, scyalen, scameralen };
  46
  47
  48 void InitSound(void)
  49 {
  50         SDL_AudioSpec desired, obtained;
  51         desired.freq = 22050;
  52         desired.format = AUDIO_U8;
  53         desired.channels = 1;
  54         desired.samples = 1024;
  55         desired.callback = SoundFunc;
  56         desired.userdata = NULL;
  57         // Also, should check to see if it got the hardware it needed, correct sample size, etc.
  58         if (SDL_OpenAudio(&desired, &obtained) < 0)
  59         {
  60                 soundInitialized = false;
  61                 printf("Couldn't open audio: %s\n", SDL_GetError());
  62                 return;
  63         }
  64
  65         // Get that audio going!
  66         SDL_PauseAudio(0);
  67         soundInitialized = true;
  68 }
  69
  70
  71 void SpawnSound(int type, int snd, int channel/* = 0*/)
  72 {
  73         extern uint32_t psg_lens[16];
  74         extern uint8_t * psg_adrs[16];
  75         extern uint32_t voc_lens[32];
  76         extern uint8_t * voc_adrs[32];
  77         extern uint32_t fm_lens[14];
  78         extern uint8_t * fm_adrs[14];
  79
  80         if (!soundInitialized)
  81                 return;
  82
  83         snd_num = snd;
  84 //      SpawnMsg(MSHOWNUMS);
  85
  86         if (type == GAMESOUND)
  87         {
  88                 // Will that do it???  Yes!!!
  89                 snd--;
  90
  91                 if (channel == 0)
  92                 {
  93                         // 00 nn ss (nn # of repeats of sample ss)
  94                         uint32_t st = 0;
  95
  96                         if (snd & 0x40)
  97                         {
  98                                 st = 0x10000;
  99                                 snd &= 0x0F;
 100                         }
 101
 102                         spos1 = (voice_rom[st + (snd << 1)] << 8) | voice_rom[st + (snd << 1) + 1];
 103                         spos1 += st;                                                            // Need to add start somewhere...
 104                         prevSamp1 = 128;
 105                         sample1 = 0;
 106                         chan1_go = true;
 107                 }
 108                 else
 109                 {
 110                         uint32_t st = 0;
 111
 112                         if (snd & 0x40)
 113                         {
 114                                 st = 0x10000;
 115                                 snd &= 0x0F;
 116                         }
 117
 118                         spos2 = (voice_rom[st + (snd << 1)] << 8) | voice_rom[st + (snd << 1) + 1];
 119                         spos2 += st;                                                            // Need to add start somewhere...
 120                         prevSamp2 = 128;
 121                         sample2 = 0;
 122                         chan2_go = true;
 123                 }
 124         }
 125         else if (type == PSGSOUND)
 126         {
 127                 if (snd_num & 0x10)                                                             // Second channel?
 128                 {
 129                         spos3 = 0;
 130                         end_pos3 = psg_lens[snd_num & 0x0F];
 131                         sndp3 = psg_adrs[snd_num & 0x0F];
 132                         chan3_go = true;
 133
 134                         if (spos3 == end_pos3)
 135                                 chan3_go = false;                                               // No sound loaded, so don't do it!
 136                 }
 137                 else                                                                                    // First channel
 138                 {
 139                         spos4 = 0;
 140                         end_pos4 = psg_lens[snd_num & 0x0F];
 141                         sndp4 = psg_adrs[snd_num & 0x0F];
 142                         chan4_go = true;
 143
 144                         if (spos4 == end_pos4)
 145                                 chan4_go = false;                                               // No sound loaded, so don't do it!
 146                 }
 147         }
 148         else if (type == FMSOUND)
 149         {
 150                 spos5 = 0;
 151                 end_pos5 = fm_lens[snd_num];
 152                 sndp5 = fm_adrs[snd_num];
 153                 chan5_go = true;
 154
 155                 if (spos5 == end_pos5)
 156                         chan5_go = false;                                                       // No sound loaded, so don't do it!
 157         }
 158         else if (type == USERSOUND)
 159         {
 160                 spos6 = 0;
 161                 end_pos6 = snd_lens[snd_num];                                   // User sound
 162                 sndp6 = snd_array[snd_num];                                             // Load pointer
 163                 chan6_go = true;
 164         }
 165 }
 166
 167
 168 void SoundFunc(void * userdata, Uint8 * buff, int num)
 169 {
 170         // 0-22 different sounds...
 171         uint16_t cnt = 0, sample;
 172         uint8_t start_samp1, end_samp1, start_samp2, end_samp2;
 173         uint8_t samp1 = 128, samp2 = 128, samp3 = 128,
 174                 samp4 = 128, samp5 = 128, samp6 = 128;                  // Zero samples...
 175
 176         // Kill sound...
 177         memset(buff, 128, num);
 178
 179         if (chan1_go || chan2_go || chan3_go || chan4_go || chan5_go || chan6_go)
 180         {
 181                 while (cnt != num)
 182                 {
 183                         if (chan1_go)
 184                         {
 185                                 if (sample1 < 1)
 186                                 {
 187                                         samp1 = voice_rom[spos1++];
 188
 189                                         // Kill channel 1 if done...
 190                                         if (samp1 == 0xFF)
 191                                         {
 192                                                 chan1_go = false;
 193                                                 samp1 = 128;
 194                                         }
 195                                         // RLE compression...
 196                                         else if (samp1 == 0x00)
 197                                         {
 198                                                 // # of repeats
 199                                                 sample1 += (float)voice_rom[spos1++] * sampleBase;
 200                                                 // Get last good sample
 201                                                 samp1   = prevSamp1;
 202                                         }
 203                                         else
 204                                                 // Keep fractional part intact
 205                                                 sample1 += sampleBase;
 206                                 }
 207
 208                                 prevSamp1 = samp1;              // Save last sample value
 209                                 sample1 -= 1.0;                 // Decrement repeat counter
 210                         }
 211
 212 // Stretching 5KHz samples to 22KHz:
 213 //   numRepeats = 4;
 214 //            6KHz -> 22KHz:  22/6 repeats...
 215                         if (chan2_go)
 216                         {
 217                                 if (sample2 < 1)
 218                                 {
 219                                         samp2 = voice_rom[spos2++];
 220
 221                                         if (samp2 == 0xFF)
 222                                         {
 223                                                 chan2_go = false;
 224                                                 samp2 = 128;                                    // Kill channel 2 if done...
 225                                         }
 226                                         else if (samp2 == 0x00)                         // RLE compression...
 227                                         {
 228                                                 sample2 += (float)voice_rom[spos2++] * sampleBase;      // # of repeats
 229                                                 samp2   = prevSamp2;
 230                                         }
 231                                         else
 232                                                 sample2 += sampleBase;
 233                                 }
 234
 235 // Delta-X values were making the samples sound like crap...
 236 //                              start_samp2 += delta_x2;
 237                                 prevSamp2 = samp2;
 238                                 sample2 -= 1.0;
 239                         }
 240
 241                         if (chan3_go)
 242                         {
 243                                 samp3 = sndp3[spos3++];
 244
 245                                 if (spos3 == end_pos3)
 246                                 {
 247                                         chan3_go = false;
 248                                         samp3 = 128; // Kill channel 3 if done...
 249                                 }
 250                         }
 251
 252                         if (chan4_go)
 253                         {
 254                                 samp4 = sndp4[spos4++];
 255
 256                                 if (spos4 == end_pos4)
 257                                 {
 258                                         chan4_go = false;
 259                                         samp4 = 128; // Kill channel 4 if done...
 260                                 }
 261                         }
 262
 263                         if (chan5_go)
 264                         {
 265                                 samp5 = sndp5[spos5++];
 266
 267                                 if (spos5 == end_pos5)
 268                                 {
 269                                         chan5_go = false;
 270                                         samp5 = 128; // Kill channel 5 if done...
 271                                 }
 272                         }
 273
 274                         if (chan6_go)
 275                         {
 276                                 samp6 = sndp6[spos6++];
 277
 278                                 if (spos6 == end_pos6)
 279                                 {
 280                                         chan6_go = false;
 281                                         samp6 = 128;            // Kill channel 6...
 282                                 }
 283                         }
 284
 285                         // Mix 'em...
 286                         sample = samp1 + samp2 + samp3 + samp4 + samp5 + samp6 - 640;
 287
 288                         // If it overflowed, clip it
 289                         if (sample & 0xFF00)
 290                                 sample = (sample & 0x8000 ? 0x00 : 0xFF);
 291
 292                         buff[cnt++] = sample;
 293                 }
 294         }
 295 }
 296