source/src/vm/pv1000/psg.cpp

   1 /*
   2         CASIO PV-1000 Emulator 'ePV-1000'
   3
   4         Author : Takeda.Toshiya
   5         Date   : 2006.11.16 -
   6
   7         [ psg ]
   8 */
   9
  10 #include <math.h>
  11 #include "psg.h"
  12
  13 #define PSG_CLOCK
  14 #define PSG_VOLUME      8192
  15
  16 void PSG::reset()
  17 {
  18         touch_sound();
  19         memset(ch, 0, sizeof(ch));
  20 }
  21
  22 void PSG::write_io8(uint32_t addr, uint32_t data)
  23 {
  24         touch_sound();
  25         ch[addr & 3].period = 0x3f - (data & 0x3f);
  26 }
  27
  28 void PSG::initialize_sound(int rate)
  29 {
  30         diff = (int)(1.3 * (double)CPU_CLOCKS / (double)rate + 0.5);
  31 }
  32
  33 void PSG::mix(int32_t* buffer, int cnt)
  34 {
  35         // create sound buffer
  36         for(int i = 0; i < cnt; i++) {
  37                 int vol = 0;
  38                 for(int j = 0; j < 3; j++) {
  39                         if(!ch[j].period) {
  40                                 continue;
  41                         }
  42                         bool prev_signal = ch[j].signal;
  43                         int prev_count = ch[j].count;
  44                         ch[j].count -= diff;
  45                         if(ch[j].count < 0) {
  46                                 ch[j].count += ch[j].period << 8;
  47                                 ch[j].signal = !ch[j].signal;
  48                         }
  49                         int vol_tmp = (prev_signal != ch[j].signal && prev_count < diff) ? (PSG_VOLUME * (2 * prev_count - diff)) / diff : PSG_VOLUME;
  50                         vol += prev_signal ? vol_tmp : -vol_tmp;
  51                 }
  52                 *buffer++ += apply_volume(vol, volume_l); // L
  53                 *buffer++ += apply_volume(vol, volume_l); // R
  54         }
  55 }
  56
  57 void PSG::set_volume(int ch, int decibel_l, int decibel_r)
  58 {
  59         volume_l = decibel_to_volume(decibel_l);
  60         volume_r = decibel_to_volume(decibel_r);
  61 }
  62
  63 #define STATE_VERSION   1
  64
  65 #include "../../statesub.h"
  66
  67 void PSG::decl_state()
  68 {
  69         enter_decl_state(STATE_VERSION);
  70
  71         DECL_STATE_ENTRY_INT32_STRIDE((ch[0].period), 3, sizeof(ch[0]));
  72
  73         leave_decl_state();
  74 }
  75
  76 void PSG::save_state(FILEIO* state_fio)
  77 {
  78         if(state_entry != NULL) {
  79                 state_entry->save_state(state_fio);
  80         }
  81 //      state_fio->FputUint32(STATE_VERSION);
  82 //      state_fio->FputInt32(this_device_id);
  83
  84 //      for(int i = 0; i < 3; i++) {
  85 //              state_fio->FputInt32(ch[i].period);
  86 //      }
  87 }
  88
  89 bool PSG::load_state(FILEIO* state_fio)
  90 {
  91         bool mb = false;
  92         if(state_entry != NULL) {
  93                 mb = state_entry->load_state(state_fio);
  94         }
  95         if(!mb) {
  96                 return false;
  97         }
  98 //      if(state_fio->FgetUint32() != STATE_VERSION) {
  99 //              return false;
 100 //      }
 101 //      if(state_fio->FgetInt32() != this_device_id) {
 102 //              return false;
 103 //      }
 104 //      for(int i = 0; i < 3; i++) {
 105 //              ch[i].period = state_fio->FgetInt32();
 106 //      }
 107         return true;
 108 }
 109
 110 bool PSG::process_state(FILEIO* state_fio, bool loading)
 111 {
 112         if(!state_fio->StateCheckUint32(STATE_VERSION)) {
 113                 return false;
 114         }
 115         if(!state_fio->StateCheckInt32(this_device_id)) {
 116                 return false;
 117         }
 118         for(int i = 0; i < 3; i++) {
 119                 state_fio->StateInt32(ch[i].period);
 120         }
 121         return true;
 122 }