furnace/src/engine/engine.cpp

#include "engine.h"
#include "instrument.h"
#include "safeReader.h"
#include "../ta-log.h"
#include "../audio/sdl.h"
#ifdef HAVE_JACK
#include "../audio/jack.h"
#endif
#include "platform/genesis.h"
#include "platform/genesisext.h"
#include "platform/sms.h"
#include "platform/gb.h"
#include "platform/pce.h"
#include "platform/nes.h"
#include "platform/c64.h"
#include "platform/arcade.h"
#include "platform/ym2610.h"
#include "platform/dummy.h"
#include <math.h>
#include <zlib.h>
#include <sndfile.h>

void process(void* u, float** in, float** out, int inChans, int outChans, unsigned int size) {
  ((DivEngine*)u)->nextBuf(in,out,inChans,outChans,size);
}

#define DIV_READ_SIZE 131072
#define DIV_DMF_MAGIC ".DelekDefleMask."

struct InflateBlock {
  unsigned char* buf;
  size_t len;
  size_t blockSize;
  InflateBlock(size_t s) {
    buf=new unsigned char[s];
    len=s;
    blockSize=0;
  }
  ~InflateBlock() {
    delete[] buf;
    len=0;
  }
};

DivSystem systemFromFile(unsigned char val) {
  switch (val) {
    case 0x01:
      return DIV_SYSTEM_YMU759;
    case 0x02:
      return DIV_SYSTEM_GENESIS;
    case 0x03:
      return DIV_SYSTEM_SMS;
    case 0x04:
      return DIV_SYSTEM_GB;
    case 0x05:
      return DIV_SYSTEM_PCE;
    case 0x06:
      return DIV_SYSTEM_NES;
    case 0x07:
      return DIV_SYSTEM_C64_8580;
    case 0x08:
      return DIV_SYSTEM_ARCADE;
    case 0x09:
      return DIV_SYSTEM_YM2610;
    case 0x42:
      return DIV_SYSTEM_GENESIS_EXT;
    case 0x47:
      return DIV_SYSTEM_C64_6581;
    case 0x49:
      return DIV_SYSTEM_YM2610_EXT;
  }
  return DIV_SYSTEM_NULL;
}

unsigned char systemToFile(DivSystem val) {
  switch (val) {
    case DIV_SYSTEM_YMU759:
      return 0x01;
    case DIV_SYSTEM_GENESIS:
      return 0x02;
    case DIV_SYSTEM_SMS:
      return 0x03;
    case DIV_SYSTEM_GB:
      return 0x04;
    case DIV_SYSTEM_PCE:
      return 0x05;
    case DIV_SYSTEM_NES:
      return 0x06;
    case DIV_SYSTEM_C64_8580:
      return 0x07;
    case DIV_SYSTEM_ARCADE:
      return 0x08;
    case DIV_SYSTEM_YM2610:
      return 0x09;
    case DIV_SYSTEM_GENESIS_EXT:
      return 0x42;
    case DIV_SYSTEM_C64_6581:
      return 0x47;
    case DIV_SYSTEM_YM2610_EXT:
      return 0x49;
    case DIV_SYSTEM_NULL:
      return 0;
  }
  return 0;
}

int getChannelCount(DivSystem sys) {
  switch (sys) {
    case DIV_SYSTEM_NULL:
      return 0;
    case DIV_SYSTEM_YMU759:
      return 17;
    case DIV_SYSTEM_GENESIS:
      return 10;
    case DIV_SYSTEM_SMS:
    case DIV_SYSTEM_GB:
      return 4;
    case DIV_SYSTEM_PCE:
      return 6;
    case DIV_SYSTEM_NES:
      return 5;
    case DIV_SYSTEM_C64_6581:
    case DIV_SYSTEM_C64_8580:
      return 3;
    case DIV_SYSTEM_ARCADE:
    case DIV_SYSTEM_GENESIS_EXT:
    case DIV_SYSTEM_YM2610:
      return 13;      
    case DIV_SYSTEM_YM2610_EXT:
      return 16;
  }
  return 0;
}

bool DivEngine::load(void* f, size_t slen) {
  unsigned char* file;
  size_t len;
  if (slen<16) {
    logE("too small!");
    return false;
  }
  if (memcmp(f,DIV_DMF_MAGIC,16)!=0) {
    logD("loading as zlib...\n");
    // try zlib
    z_stream zl;
    memset(&zl,0,sizeof(z_stream));

    zl.avail_in=slen;
    zl.next_in=(Bytef*)f;
    zl.zalloc=NULL;
    zl.zfree=NULL;
    zl.opaque=NULL;

    int nextErr;
    nextErr=inflateInit(&zl);
    if (nextErr!=Z_OK) {
      if (zl.msg==NULL) {
        logE("zlib error: unknown! %d\n",nextErr);
      } else {
        logE("zlib error: %s\n",zl.msg);
      }
      return false;
    }

    std::vector<InflateBlock*> blocks;
    while (true) {
      InflateBlock* ib=new InflateBlock(DIV_READ_SIZE);
      zl.next_out=ib->buf;
      zl.avail_out=ib->len;

      nextErr=inflate(&zl,Z_SYNC_FLUSH);
      if (nextErr!=Z_OK && nextErr!=Z_STREAM_END) {
        if (zl.msg==NULL) {
          logE("zlib error: unknown error! %d\n",nextErr);
        } else {
          logE("zlib inflate: %s\n",zl.msg);
        }
        for (InflateBlock* i: blocks) delete i;
        blocks.clear();
        delete ib;
        return false;
      }
      ib->blockSize=ib->len-zl.avail_out;
      blocks.push_back(ib);
      if (nextErr==Z_STREAM_END) {
        break;
      }
    }
    nextErr=inflateEnd(&zl);
    if (nextErr!=Z_OK) {
      if (zl.msg==NULL) {
        logE("zlib end error: unknown error! %d\n",nextErr);
      } else {
        logE("zlib end: %s\n",zl.msg);
      }
      for (InflateBlock* i: blocks) delete i;
      blocks.clear();
      return false;
    }

    size_t finalSize=0;
    size_t curSeek=0;
    for (InflateBlock* i: blocks) {
      finalSize+=i->blockSize;
    }
    if (finalSize<1) {
      logE("compressed too small!\n");
      for (InflateBlock* i: blocks) delete i;
      blocks.clear();
      return false;
    }
    file=new unsigned char[finalSize];
    for (InflateBlock* i: blocks) {
      memcpy(&file[curSeek],i->buf,i->blockSize);
      curSeek+=i->blockSize;
      delete i;
    }
    blocks.clear();
    len=finalSize;
  } else {
    logD("loading as uncompressed\n");
    file=(unsigned char*)f;
    len=slen;
  }
  if (memcmp(file,DIV_DMF_MAGIC,16)!=0) {
    logE("not a valid module!\n");
    return false;
  }
  SafeReader reader=SafeReader(file,len);
  try {
    DivSong ds;

    ds.nullWave.len=32;
    for (int i=0; i<32; i++) {
      ds.nullWave.data[i]=15;
    }

    if (!reader.seek(16,SEEK_SET)) {
      logE("premature end of file!");
      return false;
    }
    ds.version=reader.readC();
    logI("module version %d (0x%.2x)\n",ds.version,ds.version);
    unsigned char sys=0;
    if (ds.version<0x09) {
      // V E R S I O N  -> 3 <-
      // AWESOME
      ds.system=DIV_SYSTEM_YMU759;
    } else {
      sys=reader.readC();
      ds.system=systemFromFile(sys);
    }
    if (ds.system==DIV_SYSTEM_NULL) {
      logE("invalid system 0x%.2x!",sys);
      return false;
    }
    
    if (ds.system==DIV_SYSTEM_YMU759 && ds.version<0x10) { // TODO
      ds.vendor=reader.readString((unsigned char)reader.readC());
      ds.carrier=reader.readString((unsigned char)reader.readC());
      ds.category=reader.readString((unsigned char)reader.readC());
      ds.name=reader.readString((unsigned char)reader.readC());
      ds.author=reader.readString((unsigned char)reader.readC());
      ds.writer=reader.readString((unsigned char)reader.readC());
      ds.composer=reader.readString((unsigned char)reader.readC());
      ds.arranger=reader.readString((unsigned char)reader.readC());
      ds.copyright=reader.readString((unsigned char)reader.readC());
      ds.manGroup=reader.readString((unsigned char)reader.readC());
      ds.manInfo=reader.readString((unsigned char)reader.readC());
      ds.createdDate=reader.readString((unsigned char)reader.readC());
      ds.revisionDate=reader.readString((unsigned char)reader.readC());
      logI("%s by %s\n",ds.name.c_str(),ds.author.c_str());
      logI("has YMU-specific data:\n");
      logI("- carrier: %s\n",ds.carrier.c_str());
      logI("- category: %s\n",ds.category.c_str());
      logI("- vendor: %s\n",ds.vendor.c_str());
      logI("- writer: %s\n",ds.writer.c_str());
      logI("- composer: %s\n",ds.composer.c_str());
      logI("- arranger: %s\n",ds.arranger.c_str());
      logI("- copyright: %s\n",ds.copyright.c_str());
      logI("- management group: %s\n",ds.manGroup.c_str());
      logI("- management info: %s\n",ds.manInfo.c_str());
      logI("- created on: %s\n",ds.createdDate.c_str());
      logI("- revision date: %s\n",ds.revisionDate.c_str());
    } else {
      ds.name=reader.readString((unsigned char)reader.readC());
      ds.author=reader.readString((unsigned char)reader.readC());
      logI("%s by %s\n",ds.name.c_str(),ds.author.c_str());
    }

    logI("reading module data...\n");
    if (ds.version>0x0c) {
      ds.hilightA=reader.readC();
      ds.hilightB=reader.readC();
    }

    ds.timeBase=reader.readC();
    ds.speed1=reader.readC();
    if (ds.version>0x03) {
      ds.speed2=reader.readC();
      ds.pal=reader.readC();
      ds.customTempo=reader.readC();
    } else {
      ds.speed2=ds.speed1;
    }
    if (ds.version>0x0a) {
      String hz=reader.readString(3);
      if (ds.customTempo) {
        ds.hz=std::stoi(hz);
      }
    }
    // TODO
    if (ds.version>0x17) {
      ds.patLen=reader.readI();
    } else {
      ds.patLen=(unsigned char)reader.readC();
    }
    ds.ordersLen=(unsigned char)reader.readC();

    if (ds.version<20 && ds.version>3) {
      ds.arpLen=reader.readC();
    } else {
      ds.arpLen=1;
    }

    logI("reading pattern matrix (%d)...\n",ds.ordersLen);
    for (int i=0; i<getChannelCount(ds.system); i++) {
      for (int j=0; j<ds.ordersLen; j++) {
        ds.orders.ord[i][j]=reader.readC();
      }
    }

    if (ds.version>0x03) {
      ds.insLen=reader.readC();
    } else {
      ds.insLen=16;
    }
    logI("reading instruments (%d)...\n",ds.insLen);
    for (int i=0; i<ds.insLen; i++) {
      DivInstrument* ins=new DivInstrument;
      if (ds.version>0x03) {
        ins->name=reader.readString((unsigned char)reader.readC());
      }
      logD("%d name: %s\n",i,ins->name.c_str());
      if (ds.version<0x0b) {
        // instruments in ancient versions were all FM or STD.
        ins->mode=1;
      } else {
        ins->mode=reader.readC();
      }

      if (ins->mode) { // FM
        if (ds.system!=DIV_SYSTEM_GENESIS &&
            ds.system!=DIV_SYSTEM_GENESIS_EXT &&
            ds.system!=DIV_SYSTEM_ARCADE &&
            ds.system!=DIV_SYSTEM_YM2610 &&
            ds.system!=DIV_SYSTEM_YM2610_EXT &&
            ds.system!=DIV_SYSTEM_YMU759) {
          logE("FM instrument in non-FM system. oopsie?\n");
          return false;
        }
        ins->fm.alg=reader.readC();
        if (ds.version<0x13) {
          reader.readC();
        }
        ins->fm.fb=reader.readC();
        if (ds.version<0x13) {
          reader.readC();
        }
        ins->fm.fms=reader.readC();
        if (ds.version<0x13) {
          reader.readC();
          ins->fm.ops=2+reader.readC()*2;
          if (ds.system!=DIV_SYSTEM_YMU759) ins->fm.ops=4;
        } else {
          ins->fm.ops=4;
        }
        if (ins->fm.ops!=2 && ins->fm.ops!=4) {
          logE("invalid op count %d. did we read it wrong?\n",ins->fm.ops);
          return false;
        }
        ins->fm.ams=reader.readC();

        for (int j=0; j<ins->fm.ops; j++) {
          ins->fm.op[j].am=reader.readC();
          ins->fm.op[j].ar=reader.readC();
          if (ds.version<0x13) {
            ins->fm.op[j].dam=reader.readC();
          }
          ins->fm.op[j].dr=reader.readC();
          if (ds.version<0x13) {
            ins->fm.op[j].dvb=reader.readC();
            ins->fm.op[j].egt=reader.readC();
            ins->fm.op[j].ksl=reader.readC();
            if (ds.version<0x11) { // TODO: don't know when did this change
              ins->fm.op[j].ksr=reader.readC();
            }
          }
          ins->fm.op[j].mult=reader.readC();
          ins->fm.op[j].rr=reader.readC();
          ins->fm.op[j].sl=reader.readC();
          if (ds.version<0x13) {
            ins->fm.op[j].sus=reader.readC();
          }
          ins->fm.op[j].tl=reader.readC();
          if (ds.version<0x13) {
            ins->fm.op[j].vib=reader.readC();
            ins->fm.op[j].ws=reader.readC();
          } else {
            ins->fm.op[j].dt2=reader.readC();
          }
          if (ds.version>0x03) {
            ins->fm.op[j].rs=reader.readC();
            ins->fm.op[j].dt=reader.readC();
            ins->fm.op[j].d2r=reader.readC();
            ins->fm.op[j].ssgEnv=reader.readC();
          }

          logD("OP%d: AM %d AR %d DAM %d DR %d DVB %d EGT %d KSL %d MULT %d RR %d SL %d SUS %d TL %d VIB %d WS %d RS %d DT %d D2R %d SSG-EG %d\n",j,
               ins->fm.op[j].am,
               ins->fm.op[j].ar,
               ins->fm.op[j].dam,
               ins->fm.op[j].dr,
               ins->fm.op[j].dvb,
               ins->fm.op[j].egt,
               ins->fm.op[j].ksl,
               ins->fm.op[j].mult,
               ins->fm.op[j].rr,
               ins->fm.op[j].sl,
               ins->fm.op[j].sus,
               ins->fm.op[j].tl,
               ins->fm.op[j].vib,
               ins->fm.op[j].ws,
               ins->fm.op[j].rs,
               ins->fm.op[j].dt,
               ins->fm.op[j].d2r,
               ins->fm.op[j].ssgEnv
               );
        }
      } else { // STD
        if (ds.system!=DIV_SYSTEM_GB || ds.version<0x12) {
          ins->std.volMacroLen=reader.readC();
          for (int j=0; j<ins->std.volMacroLen; j++) {
            if (ds.version<0x0e) {
              ins->std.volMacro[j]=reader.readC();
            } else {
              ins->std.volMacro[j]=reader.readI();
            }
          }
          if (ins->std.volMacroLen>0) {
            ins->std.volMacroLoop=reader.readC();
          }
        }

        ins->std.arpMacroLen=reader.readC();
        for (int j=0; j<ins->std.arpMacroLen; j++) {
          if (ds.version<0x0e) {
            ins->std.arpMacro[j]=reader.readC();
          } else {
            ins->std.arpMacro[j]=reader.readI();
          }
        }
        if (ins->std.arpMacroLen>0) {
          ins->std.arpMacroLoop=reader.readC();
        }
        if (ds.version>0x0f) { // TODO
          ins->std.arpMacroMode=reader.readC();
        }

        ins->std.dutyMacroLen=reader.readC();
        for (int j=0; j<ins->std.dutyMacroLen; j++) {
          if (ds.version<0x0e) {
            ins->std.dutyMacro[j]=reader.readC();
          } else {
            ins->std.dutyMacro[j]=reader.readI();
          }
        }
        if (ins->std.dutyMacroLen>0) {
          ins->std.dutyMacroLoop=reader.readC();
        }

        ins->std.waveMacroLen=reader.readC();
        for (int j=0; j<ins->std.waveMacroLen; j++) {
          if (ds.version<0x0e) {
            ins->std.waveMacro[j]=reader.readC();
          } else {
            ins->std.waveMacro[j]=reader.readI();
          }
        }
        if (ins->std.waveMacroLen>0) {
          ins->std.waveMacroLoop=reader.readC();
        }

        if (ds.system==DIV_SYSTEM_C64_6581 || ds.system==DIV_SYSTEM_C64_8580) {
          ins->c64.triOn=reader.readC();
          ins->c64.sawOn=reader.readC();
          ins->c64.pulseOn=reader.readC();
          ins->c64.noiseOn=reader.readC();

          ins->c64.a=reader.readC();
          ins->c64.d=reader.readC();
          ins->c64.s=reader.readC();
          ins->c64.r=reader.readC();

          ins->c64.duty=reader.readC();

          ins->c64.ringMod=reader.readC();
          ins->c64.oscSync=reader.readC();
          ins->c64.toFilter=reader.readC();
          if (ds.version<0x11) {
            ins->c64.volIsCutoff=reader.readI();
          } else {
            ins->c64.volIsCutoff=reader.readC();
          }
          ins->c64.initFilter=reader.readC();

          ins->c64.res=reader.readC();
          ins->c64.cut=reader.readC();
          ins->c64.hp=reader.readC();
          ins->c64.bp=reader.readC();
          ins->c64.lp=reader.readC();
          ins->c64.ch3off=reader.readC();
        }

        if (ds.system==DIV_SYSTEM_GB && ds.version>0x11) {
          ins->gb.envVol=reader.readC();
          ins->gb.envDir=reader.readC();
          ins->gb.envLen=reader.readC();
          ins->gb.soundLen=reader.readC();

          logD("GB data: vol %d dir %d len %d sl %d\n",ins->gb.envVol,ins->gb.envDir,ins->gb.envLen,ins->gb.soundLen);
        }
      }

      ds.ins.push_back(ins);
    }

    if (ds.version>0x0b) {
      ds.waveLen=(unsigned char)reader.readC();
      logI("reading wavetables (%d)...\n",ds.waveLen);
      for (int i=0; i<ds.waveLen; i++) {
        DivWavetable* wave=new DivWavetable;
        wave->len=(unsigned char)reader.readI();
        if (wave->len>32) {
          logE("invalid wave length %d. are we doing something wrong?\n",wave->len);
          return false;
        }
        logD("%d length %d\n",i,wave->len);
        for (int j=0; j<wave->len; j++) {
          if (ds.version<0x0e) {
            wave->data[j]=reader.readC();
          } else {
            wave->data[j]=reader.readI();
          }
        }
        ds.wave.push_back(wave);
      }
    }

    logI("reading patterns (%d channels, %d orders)...\n",getChannelCount(ds.system),ds.ordersLen);
    for (int i=0; i<getChannelCount(ds.system); i++) {
      DivChannelData* chan=new DivChannelData;
      if (ds.version<0x0a) {
        chan->effectRows=1;
      } else {
        chan->effectRows=reader.readC();
      }
      logD("%d fx rows: %d\n",i,chan->effectRows);
      if (chan->effectRows>4 || chan->effectRows<1) {
        logE("invalid effect row count %d. are you sure everything is ok?\n",chan->effectRows);
        return false;
      }
      for (int j=0; j<ds.ordersLen; j++) {
        DivPattern* pat=chan->getPattern(ds.orders.ord[i][j],true);
        for (int k=0; k<ds.patLen; k++) {
          // note
          pat->data[k][0]=reader.readS();
          // octave
          pat->data[k][1]=reader.readS();
          if (ds.system==DIV_SYSTEM_SMS && ds.version<0x0e && pat->data[k][1]>0) {
            // apparently it was up one octave before
            pat->data[k][1]--;
          } else if (ds.system==DIV_SYSTEM_GENESIS && ds.version<0x0e && pat->data[k][1]>0 && i>5) {
            // ditto
            pat->data[k][1]--;
          }
          // volume
          pat->data[k][3]=reader.readS();
          if (ds.version<0x0a) {
            // back then volume was stored as 00-ff instead of 00-7f/0-f
            if (i>5) {
              pat->data[k][3]>>=4;
            } else {
              pat->data[k][3]>>=1;
            }
          }
          for (int l=0; l<chan->effectRows; l++) {
            // effect
            pat->data[k][4+(l<<1)]=reader.readS();
            pat->data[k][5+(l<<1)]=reader.readS();
          }
          // instrument
          pat->data[k][2]=reader.readS();
        }
      }
      ds.pat.push_back(chan);
    }

    ds.sampleLen=reader.readC();
    logI("reading samples (%d)...\n",ds.sampleLen);
    if (ds.version<0x0b && ds.sampleLen>0) { // TODO what is this for?
      reader.readC();
    }
    for (int i=0; i<ds.sampleLen; i++) {
      DivSample* sample=new DivSample;
      sample->length=reader.readI();
      if (sample->length<0) {
        logE("invalid sample length %d. are we doing something wrong?\n",sample->length);
        return false;
      }
      if (ds.version>0x16) {
        sample->name=reader.readString((unsigned char)reader.readC());
      } else {
        sample->name="";
      }
      logD("%d name %s (%d)\n",i,sample->name.c_str(),sample->length);
      if (ds.version<0x0b) {
        sample->rate=4;
        sample->pitch=0;
        sample->vol=0;
      } else {
        sample->rate=reader.readC();
        sample->pitch=reader.readC();
        sample->vol=reader.readC();
      }
      if (ds.version>0x15) {
        sample->depth=reader.readC();
      } else {
        sample->depth=16;
      }
      if (sample->length>0) {
        if (ds.version<0x0b) {
          sample->data=new short[1+(sample->length/2)];
          reader.read(sample->data,sample->length);
          sample->length/=2;
        } else {
          sample->data=new short[sample->length];
          reader.read(sample->data,sample->length*2);
        }
      }
      ds.sample.push_back(sample);
    }

    if (reader.tell()<reader.size()) {
      if ((reader.tell()+1)!=reader.size()) {
        logW("premature end of song (we are at %x, but size is %x)\n",reader.tell(),reader.size());
      }
    }

    song=ds;
    chans=getChannelCount(song.system);
    renderSamples();
  } catch (EndOfFileException e) {
    logE("premature end of file!\n");
    return false;
  }
  return true;
}

#define ERR_CHECK(x) x; if (ferror(f)) return false;

bool DivEngine::save(FILE* f) {
  // write magic
  ERR_CHECK(fwrite(DIV_DMF_MAGIC,1,16,f));
  // version
  ERR_CHECK(fputc(24,f));
  ERR_CHECK(fputc(systemToFile(song.system),f));

  // song info
  ERR_CHECK(fputc(song.name.size(),f));
  ERR_CHECK(fwrite(song.name.c_str(),1,song.name.size(),f));
  ERR_CHECK(fputc(song.author.size(),f));
  ERR_CHECK(fwrite(song.author.c_str(),1,song.author.size(),f));
  ERR_CHECK(fputc(song.hilightA,f));
  ERR_CHECK(fputc(song.hilightB,f));
  
  ERR_CHECK(fputc(song.timeBase,f));
  ERR_CHECK(fputc(song.speed1,f));
  ERR_CHECK(fputc(song.speed2,f));
  ERR_CHECK(fputc(song.pal,f));
  ERR_CHECK(fputc(song.customTempo,f));
  char customHz[4];
  memset(customHz,0,4);
  snprintf(customHz,4,"%d",song.hz);
  ERR_CHECK(fwrite(customHz,1,3,f));
  ERR_CHECK(fwrite(&song.patLen,4,1,f));
  ERR_CHECK(fputc(song.ordersLen,f));

  for (int i=0; i<getChannelCount(song.system); i++) {
    for (int j=0; j<song.ordersLen; j++) {
      ERR_CHECK(fputc(song.orders.ord[i][j],f));
    }
  }

  ERR_CHECK(fputc(song.ins.size(),f));
  for (DivInstrument* i: song.ins) {
    ERR_CHECK(fputc(i->name.size(),f));
    ERR_CHECK(fwrite(i->name.c_str(),1,i->name.size(),f));
    ERR_CHECK(fputc(i->mode,f));
    if (i->mode) { // FM
      ERR_CHECK(fputc(i->fm.alg,f));
      ERR_CHECK(fputc(i->fm.fb,f));
      ERR_CHECK(fputc(i->fm.fms,f));
      ERR_CHECK(fputc(i->fm.ams,f));

      for (int j=0; j<4; j++) {
        DivInstrumentFM::Operator& op=i->fm.op[j];
        ERR_CHECK(fputc(op.am,f));
        ERR_CHECK(fputc(op.ar,f));
        ERR_CHECK(fputc(op.dr,f));
        ERR_CHECK(fputc(op.mult,f));
        ERR_CHECK(fputc(op.rr,f));
        ERR_CHECK(fputc(op.sl,f));
        ERR_CHECK(fputc(op.tl,f));
        ERR_CHECK(fputc(op.dt2,f));
        ERR_CHECK(fputc(op.rs,f));
        ERR_CHECK(fputc(op.dt,f));
        ERR_CHECK(fputc(op.d2r,f));
        ERR_CHECK(fputc(op.ssgEnv,f));
      }
    } else { // STD
      if (song.system!=DIV_SYSTEM_GB) {
        ERR_CHECK(fputc(i->std.volMacroLen,f));
        ERR_CHECK(fwrite(i->std.volMacro,4,i->std.volMacroLen,f));
        if (i->std.volMacroLen>0) {
          ERR_CHECK(fputc(i->std.volMacroLoop,f));
        }
      }

      ERR_CHECK(fputc(i->std.arpMacroLen,f));
      ERR_CHECK(fwrite(i->std.arpMacro,4,i->std.arpMacroLen,f));
      if (i->std.arpMacroLen>0) {
        ERR_CHECK(fputc(i->std.arpMacroLoop,f));
      }
      ERR_CHECK(fputc(i->std.arpMacroMode,f));

      ERR_CHECK(fputc(i->std.dutyMacroLen,f));
      ERR_CHECK(fwrite(i->std.dutyMacro,4,i->std.dutyMacroLen,f));
      if (i->std.dutyMacroLen>0) {
        ERR_CHECK(fputc(i->std.dutyMacroLoop,f));
      }

      ERR_CHECK(fputc(i->std.waveMacroLen,f));
      ERR_CHECK(fwrite(i->std.waveMacro,4,i->std.waveMacroLen,f));
      if (i->std.waveMacroLen>0) {
        ERR_CHECK(fputc(i->std.waveMacroLoop,f));
      }

      if (song.system==DIV_SYSTEM_C64_6581 || song.system==DIV_SYSTEM_C64_8580) {
        ERR_CHECK(fputc(i->c64.triOn,f));
        ERR_CHECK(fputc(i->c64.sawOn,f));
        ERR_CHECK(fputc(i->c64.pulseOn,f));
        ERR_CHECK(fputc(i->c64.noiseOn,f));

        ERR_CHECK(fputc(i->c64.a,f));
        ERR_CHECK(fputc(i->c64.d,f));
        ERR_CHECK(fputc(i->c64.s,f));
        ERR_CHECK(fputc(i->c64.r,f));

        ERR_CHECK(fputc(i->c64.duty,f));

        ERR_CHECK(fputc(i->c64.ringMod,f));
        ERR_CHECK(fputc(i->c64.oscSync,f));

        ERR_CHECK(fputc(i->c64.toFilter,f));
        ERR_CHECK(fputc(i->c64.volIsCutoff,f));
        ERR_CHECK(fputc(i->c64.initFilter,f));

        ERR_CHECK(fputc(i->c64.res,f));
        ERR_CHECK(fputc(i->c64.cut,f));
        ERR_CHECK(fputc(i->c64.hp,f));
        ERR_CHECK(fputc(i->c64.bp,f));
        ERR_CHECK(fputc(i->c64.lp,f));
        ERR_CHECK(fputc(i->c64.ch3off,f));
      }

      if (song.system==DIV_SYSTEM_GB) {
        ERR_CHECK(fputc(i->gb.envVol,f));
        ERR_CHECK(fputc(i->gb.envDir,f));
        ERR_CHECK(fputc(i->gb.envLen,f));
        ERR_CHECK(fputc(i->gb.soundLen,f));
      }
    }
  }

  ERR_CHECK(fputc(song.wave.size(),f));
  for (DivWavetable* i: song.wave) {
    ERR_CHECK(fwrite(&i->len,4,1,f));
    ERR_CHECK(fwrite(&i->data,4,i->len,f));
  }

  for (int i=0; i<song.pat.size(); i++) {
    ERR_CHECK(fputc(song.pat[i]->effectRows,f));

    for (int j=0; j<song.ordersLen; j++) {
      DivPattern* pat=song.pat[i]->getPattern(song.orders.ord[i][j],false);
      for (int k=0; k<song.patLen; k++) {
        ERR_CHECK(fwrite(&pat->data[k][0],2,1,f)); // note
        ERR_CHECK(fwrite(&pat->data[k][1],2,1,f)); // octave
        ERR_CHECK(fwrite(&pat->data[k][3],2,1,f)); // volume
        ERR_CHECK(fwrite(&pat->data[k][4],2,song.pat[i]->effectRows*2,f)); // volume
        ERR_CHECK(fwrite(&pat->data[k][2],2,1,f)); // instrument
      }
    }
  }

  ERR_CHECK(fputc(song.sample.size(),f));
  for (DivSample* i: song.sample) {
    ERR_CHECK(fwrite(&i->length,4,1,f));
    ERR_CHECK(fputc(i->name.size(),f));
    ERR_CHECK(fwrite(i->name.c_str(),1,i->name.size(),f));
    ERR_CHECK(fputc(i->rate,f));
    ERR_CHECK(fputc(i->pitch,f));
    ERR_CHECK(fputc(i->vol,f));
    ERR_CHECK(fputc(i->depth,f));
    ERR_CHECK(fwrite(i->data,2,i->length,f));
  }

  return true;
}

// ADPCM code attribution: https://wiki.neogeodev.org/index.php?title=ADPCM_codecs

static short adSteps[49]={ 
	16, 17, 19, 21, 23, 25, 28, 31, 34, 37,
	41, 45, 50, 55, 60, 66, 73, 80, 88, 97,
	107, 118, 130, 143, 157, 173, 190, 209, 230, 253,
	279, 307, 337, 371, 408, 449, 494, 544, 598, 658,
	724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552
};

static int adStepSeek[16]={
  -1, -1, -1, -1, 2, 5, 7, 9, -1, -1, -1, -1, 2, 5, 7, 9
};

static double samplePitches[11]={
  0.1666666666, 0.2, 0.25, 0.333333333, 0.5,
  1,
  2, 3, 4, 5, 6
};

void DivEngine::renderSamples() {
  if (jediTable==NULL) {
    jediTable=new int[16*49];
    for (int step=0; step<49; step++) {
      for (int nib=0; nib<16; nib++) {
        int value=(2*(nib&0x07)+1)*adSteps[step]/8;
        jediTable[step*16+nib]=((nib&0x08)!=0)?-value:value;
      }
    }
  }

  for (int i=0; i<song.sampleLen; i++) {
    DivSample* s=song.sample[i];
    if (s->rendLength!=0) {
      delete[] s->rendData;
      delete[] s->adpcmRendData;
    }
    s->rendLength=(double)s->length/samplePitches[s->pitch];
    s->rendData=new short[s->rendLength];
    size_t adpcmLen=((s->rendLength>>1)+255)&0xffffff00;
    s->adpcmRendLength=adpcmLen;
    s->adpcmRendData=new unsigned char[adpcmLen];
    memset(s->adpcmRendData,0,adpcmLen);

    // step 1: render to PCM
    int k=0;
    float mult=(float)(s->vol+100)/150.0f;
    for (double j=0; j<s->length; j+=samplePitches[s->pitch]) {
      if (k>=s->rendLength) {
        break;
      }
      if (s->depth==8) {
        float next=(float)(s->data[(unsigned int)j]-0x80)*mult;
        s->rendData[k++]=fmin(fmax(next,-128),127);
      } else {
        float next=(float)s->data[(unsigned int)j]*mult;
        s->rendData[k++]=fmin(fmax(next,-32768),32767);
      }
    }

    // step 2: render to ADPCM
    int acc=0;
    int decstep=0;
    int diff=0;
    int step=0;
    int predsample=0;
    int index=0;
    int prevsample=0;
    int previndex=0;
    for (int j=0; j<s->rendLength; j++) {
      unsigned char encoded=0;
      int tempstep=0;

      predsample=prevsample;
      index=previndex;
      step=adSteps[index];

      short sample=(s->depth==16)?(s->rendData[j]>>4):(s->rendData[j]<<4);
      diff=sample-predsample;
      if (diff>=0) {
        encoded=0;
      } else {
        encoded=8;
        diff=-diff;
      }

      tempstep=step;
      if (diff>=tempstep) {
        encoded|=4;
        diff-=tempstep;
      }
      tempstep>>=1;
      if (diff>=tempstep) {
        encoded|=2;
        diff-=tempstep;
      }
      tempstep>>=1;
      if (diff>=tempstep) encoded|=1;

      acc+=jediTable[decstep+encoded];
      acc&=0xfff;
      if (acc&0x800) acc|=~0xfff;
      decstep+=adStepSeek[encoded&7]*16;
      if (decstep<0) decstep=0;
      if (decstep>48*16) decstep=48*16;
      predsample=(short)acc;

      index+=adStepSeek[encoded];
      if (index<0) index=0;
      if (index>48) index=48;

      prevsample=predsample;
      previndex=index;

      if (j&1) {
        s->adpcmRendData[j>>1]|=encoded;
      } else {
        s->adpcmRendData[j>>1]=encoded<<4;
      }
    }
  }

  // step 3: allocate the samples if needed
  if (song.system==DIV_SYSTEM_YM2610 || song.system==DIV_SYSTEM_YM2610_EXT) {
    if (adpcmMem==NULL) adpcmMem=new unsigned char[16777216];

    size_t memPos=0;
    for (int i=0; i<song.sampleLen; i++) {
      DivSample* s=song.sample[i];
      if ((memPos&0xf00000)!=((memPos+s->adpcmRendLength)&0xf00000)) {
        
        memPos=(memPos+0xfffff)&0xf00000;
        printf("aligning to %lx.\n",memPos);
      }
      memcpy(adpcmMem+memPos,s->adpcmRendData,s->adpcmRendLength);
      s->rendOff=memPos;
      memPos+=s->adpcmRendLength;
    }
  }
}

DivInstrument* DivEngine::getIns(int index) {
  if (index<0 || index>=song.insLen) return &song.nullIns;
  return song.ins[index];
}

DivWavetable* DivEngine::getWave(int index) {
  if (index<0 || index>=song.waveLen) {
    if (song.waveLen>0) {
      return song.wave[0];
    } else {
      return &song.nullWave;
    }
  }
  return song.wave[index];
}

void DivEngine::setLoops(int loops) {
  remainingLoops=loops;
}

void DivEngine::play() {
  isBusy.lock();
  reset();
  curRow=0;
  clockDrift=0;
  cycles=0;
  playing=true;
  isBusy.unlock();
}

void DivEngine::stop() {
  isBusy.lock();
  playing=false;
  isBusy.unlock();
}

void DivEngine::reset() {
  for (int i=0; i<17; i++) {
    chan[i]=DivChannelState();
    chan[i].volMax=(dispatch->dispatch(DivCommand(DIV_CMD_GET_VOLMAX,i))<<8)|0xff;
    chan[i].volume=chan[i].volMax;
  }
  dispatch->reset();
}

unsigned char DivEngine::getOrder() {
  return curOrder;
}

void DivEngine::setOrder(unsigned char order) {
  isBusy.lock();
  curOrder=order;
  if (order>=song.ordersLen) curOrder=0;
  if (playing) {
    reset();
    curRow=0;
    clockDrift=0;
    cycles=0;
  }
  isBusy.unlock();
}

void DivEngine::setAudio(DivAudioEngines which) {
  audioEngine=which;
}

void DivEngine::setView(DivStatusView which) {
  view=which;
}

bool DivEngine::init(String outName) {
  SNDFILE* outFile;
  SF_INFO outInfo;
  if (outName!="") {
    // init out file
    got.bufsize=2048;
    got.rate=44100;

    outInfo.samplerate=got.rate;
    outInfo.channels=2;
    outInfo.format=SF_FORMAT_WAV|SF_FORMAT_PCM_16;

    outFile=sf_open(outName.c_str(),SFM_WRITE,&outInfo);
    if (outFile==NULL) {
      logE("could not open file for writing!\n");
      return false;
    }
  } else {
    switch (audioEngine) {
      case DIV_AUDIO_JACK:
  #ifndef HAVE_JACK
        logE("Furnace was not compiled with JACK support!\n");
        return false;
  #else
        output=new TAAudioJACK;
  #endif
        break;
      case DIV_AUDIO_SDL:
        output=new TAAudioSDL;
        break;
      default:
        logE("invalid audio engine!\n");
        return false;
    }
    want.bufsize=1024;
    want.rate=44100;
    want.fragments=2;
    want.inChans=0;
    want.outChans=2;
    want.outFormat=TA_AUDIO_FORMAT_F32;
    want.name="Furnace";
  
    output->setCallback(process,this);
  
    logI("initializing audio.\n");
    if (!output->init(want,got)) {
      logE("error while initializing audio!\n");
      return false;
    }
  }

  bb[0]=blip_new(32768);
  if (bb[0]==NULL) {
    logE("not enough memory!\n");
    return false;
  }

  bb[1]=blip_new(32768);
  if (bb[1]==NULL) {
    logE("not enough memory!\n");
    return false;
  }
  
  bbOut[0]=new short[got.bufsize];
  bbOut[1]=new short[got.bufsize];

  bbIn[0]=new short[32768];
  bbIn[1]=new short[32768];
  bbInLen=32768;

  for (int i=0; i<64; i++) {
    vibTable[i]=127*sin(((double)i/64.0)*(2*M_PI));
  }

  switch (song.system) {
    case DIV_SYSTEM_GENESIS:
      dispatch=new DivPlatformGenesis;
      break;
    case DIV_SYSTEM_GENESIS_EXT:
      dispatch=new DivPlatformGenesisExt;
      break;
    case DIV_SYSTEM_SMS:
      dispatch=new DivPlatformSMS;
      break;
    case DIV_SYSTEM_GB:
      dispatch=new DivPlatformGB;
      break;
    case DIV_SYSTEM_PCE:
      dispatch=new DivPlatformPCE;
      break;
    case DIV_SYSTEM_NES:
      dispatch=new DivPlatformNES;
      break;
    case DIV_SYSTEM_C64_6581:
      dispatch=new DivPlatformC64;
      ((DivPlatformC64*)dispatch)->setChipModel(true);
      break;
    case DIV_SYSTEM_C64_8580:
      dispatch=new DivPlatformC64;
      ((DivPlatformC64*)dispatch)->setChipModel(false);
      break;
    case DIV_SYSTEM_ARCADE:
      dispatch=new DivPlatformArcade;
      break;
    case DIV_SYSTEM_YM2610:
      dispatch=new DivPlatformYM2610;
      break;
    default:
      logW("this system is not supported yet! using dummy platform.\n");
      dispatch=new DivPlatformDummy;
      break;
  }
  dispatch->init(this,getChannelCount(song.system),got.rate,(!song.pal) || (song.customTempo!=0 && song.hz<53));

  blip_set_rates(bb[0],dispatch->rate,got.rate);
  blip_set_rates(bb[1],dispatch->rate,got.rate);

  reset();

  if (outName!="") {
    short* ilBuffer=new short[got.bufsize*2];
    // render to file
    remainingLoops=1;
    while (remainingLoops) {
      nextBuf(NULL,NULL,0,2,got.bufsize);

      if (dispatch->isStereo()) {
        for (int i=0; i<got.bufsize; i++) {
          ilBuffer[i<<1]=bbOut[0][i];
          ilBuffer[1+(i<<1)]=bbOut[1][i];
        }
      } else {
        for (int i=0; i<got.bufsize; i++) {
          ilBuffer[i<<1]=bbOut[0][i];
          ilBuffer[1+(i<<1)]=bbOut[0][i];
        }
      }

      if (!remainingLoops) {
        sf_writef_short(outFile,ilBuffer,totalProcessed);
      } else {
        sf_writef_short(outFile,ilBuffer,got.bufsize);
      }
    }
    delete[] ilBuffer;
    sf_close(outFile);
    return true;
  } else {
    if (!output->setRun(true)) {
      logE("error while activating!\n");
      return false;
    }
  }
  return true;
}