commit 783d56c72ae6cb85f9e06809dced8d9b3d1323ff
Author: tildearrow <tildearrow@protonmail.com>
Date:   Tue May 11 15:08:08 2021 -0500

    initial commit
    
    took me a day to make the base...
    ...and ~12 hours to write a reader that reads 100% of all demo songs in
    1.0

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 000000000..effc3fe8c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+.vscode/
+build/
+*.dmf
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 000000000..917350118
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,46 @@
+cmake_minimum_required(VERSION 3.0)
+project(divorce)
+
+set(CMAKE_CXX_STANDARD 11)
+
+if (WIN32)
+  add_subdirectory(SDL)
+  set(HAVE_SDL2 SDL2-static)
+else()
+  find_library(HAVE_SDL2 SDL2)
+  find_library(HAVE_JACK jack)
+endif()
+
+include_directories(include)
+
+set(AUDIO_SOURCES src/audio/abstract.cpp)
+if (HAVE_SDL2)
+  list(APPEND AUDIO_SOURCES src/audio/sdl.cpp)
+endif()
+if (HAVE_JACK)
+  list(APPEND AUDIO_SOURCES src/audio/jack.cpp)
+endif()
+
+set(ENGINE_SOURCES src/log.cpp src/engine/safeReader.cpp src/engine/engine.cpp)
+
+#imgui/imgui.cpp
+#imgui/imgui_demo.cpp
+#imgui/imgui_draw.cpp
+#imgui/imgui_tables.cpp
+#imgui/imgui_widgets.cpp
+#imgui/backends/imgui_impl_opengl3.cpp
+#imgui/backends/imgui_impl_sdl.cpp
+#src/gui/main.cpp)
+
+add_executable(divorce ${ENGINE_SOURCES} ${AUDIO_SOURCES}
+src/main.cpp)
+
+target_link_libraries(divorce ${HAVE_SDL2} z GL GLEW)
+
+if (HAVE_JACK)
+  target_link_libraries(divorce ${HAVE_JACK})
+endif()
+
+if (WIN32)
+  target_link_libraries(divorce SDL2main)
+endif()
diff --git a/README.md b/README.md
new file mode 100644
index 000000000..dc2420d29
--- /dev/null
+++ b/README.md
@@ -0,0 +1,5 @@
+# divorce
+
+that does it.
+
+this is the result of a horrible decision to make it commercial...
diff --git a/src/audio/abstract.cpp b/src/audio/abstract.cpp
new file mode 100644
index 000000000..93981801b
--- /dev/null
+++ b/src/audio/abstract.cpp
@@ -0,0 +1,30 @@
+#include "taAudio.h"
+
+void TAAudio::setSampleRateChangeCallback(void (*callback)(SampleRateChangeEvent)) {
+  sampleRateChanged=callback;
+}
+
+void TAAudio::setBufferSizeChangeCallback(void (*callback)(BufferSizeChangeEvent)) {
+  bufferSizeChanged=callback;
+}
+
+void TAAudio::setCallback(void (*callback)(float**,float**,int,int,unsigned int)) {
+  audioProcCallback=callback;
+}
+
+void* TAAudio::getContext() {
+  return NULL;
+}
+
+bool TAAudio::quit() {
+  return true;
+}
+
+bool TAAudio::setRun(bool run) {
+  running=run;
+  return running;
+}
+
+bool TAAudio::init(TAAudioDesc& request, TAAudioDesc& response) {
+  return false;
+}
\ No newline at end of file
diff --git a/src/audio/jack.cpp b/src/audio/jack.cpp
new file mode 100644
index 000000000..52bdd625e
--- /dev/null
+++ b/src/audio/jack.cpp
@@ -0,0 +1,156 @@
+#include <string.h>
+#include "jack.h"
+
+int taJACKonSampleRate(jack_nframes_t rate, void* inst) {
+  TAAudioJACK* in=(TAAudioJACK*)inst;
+  in->onSampleRate(rate);
+  return 0;
+}
+
+int taJACKonBufferSize(jack_nframes_t bufsize, void* inst) {
+  TAAudioJACK* in=(TAAudioJACK*)inst;
+  in->onBufferSize(bufsize);
+  return 0;
+}
+
+int taJACKProcess(jack_nframes_t nframes, void* inst) {
+  TAAudioJACK* in=(TAAudioJACK*)inst;
+  in->onProcess(nframes);
+  return 0;
+}
+
+void TAAudioJACK::onSampleRate(jack_nframes_t rate) {
+  if (sampleRateChanged!=NULL) {
+    sampleRateChanged(SampleRateChangeEvent(rate));
+  }
+}
+
+void TAAudioJACK::onBufferSize(jack_nframes_t bufsize) {
+  if (bufferSizeChanged!=NULL) {
+    bufferSizeChanged(BufferSizeChangeEvent(bufsize));
+  }
+}
+
+void TAAudioJACK::onProcess(jack_nframes_t nframes) {
+  if (audioProcCallback!=NULL) {
+    audioProcCallback(inBufs,outBufs,desc.inChans,desc.outChans,desc.bufsize);
+  }
+  for (int i=0; i<desc.inChans; i++) {
+    iInBufs[i]=(float*)jack_port_get_buffer(ai[i],nframes);
+    memcpy(iInBufs[i],inBufs[i],desc.bufsize*sizeof(float));
+  }
+  for (int i=0; i<desc.outChans; i++) {
+    iOutBufs[i]=(float*)jack_port_get_buffer(ao[i],nframes);
+    memcpy(iOutBufs[i],outBufs[i],desc.bufsize*sizeof(float));
+  }
+}
+
+void* TAAudioJACK::getContext() {
+  return (void*)ac;
+}
+
+bool TAAudioJACK::quit() {
+  if (!initialized) return false;
+
+  if (running) {
+    running=false;
+    if (jack_deactivate(ac)) return false;
+  }
+  
+  for (int i=0; i<desc.inChans; i++) {
+    jack_port_unregister(ac,ai[i]);
+    ai[i]=NULL;
+    delete[] inBufs[i];
+  }
+  for (int i=0; i<desc.outChans; i++) {
+    jack_port_unregister(ac,ao[i]);
+    ao[i]=NULL;
+    delete[] outBufs[i];
+  }
+
+  delete[] iInBufs;
+  delete[] iOutBufs;
+  delete[] inBufs;
+  delete[] outBufs;
+  delete[] ai;
+  delete[] ao;
+  
+  jack_client_close(ac);
+  ac=NULL;
+
+  initialized=false;
+
+  return true;
+}
+
+bool TAAudioJACK::setRun(bool run) {
+  if (!initialized) return false;
+  if (running==run) {
+    return running;
+  }
+  if (run) {
+    if (jack_activate(ac)) return false;
+    
+    for (int i=0; i<desc.outChans; i++) {
+      jack_connect(ac,(desc.name+String(":out")+std::to_string(i)).c_str(),(String("system:playback_")+std::to_string(i+1)).c_str());
+    }
+    running=true;
+  } else {
+    if (jack_deactivate(ac)) return true;
+    running=false;
+  }
+  return running;
+}
+
+bool TAAudioJACK::init(TAAudioDesc& request, TAAudioDesc& response) {
+  if (initialized) return false;
+  desc=request;
+  desc.outFormat=TA_AUDIO_FORMAT_F32;
+
+  jack_status_t as;
+  ac=jack_client_open(desc.name.c_str(),JackNoStartServer,&as);
+  if (ac==NULL) return false;
+
+  desc.name=String(jack_get_client_name(ac));
+  jack_set_sample_rate_callback(ac,taJACKonSampleRate,this);
+  jack_set_buffer_size_callback(ac,taJACKonBufferSize,this);
+  jack_set_process_callback(ac,taJACKProcess,this);
+
+  jack_nframes_t count=jack_get_buffer_size(ac);
+  desc.bufsize=count;
+  desc.fragments=1;
+
+  jack_nframes_t sampleRate=jack_get_sample_rate(ac);
+  desc.rate=sampleRate;
+
+  if (desc.inChans>0) {
+    inBufs=new float*[desc.inChans];
+    iInBufs=new float*[desc.inChans];
+    ai=new jack_port_t*[desc.inChans];
+    for (int i=0; i<desc.inChans; i++) {
+      ai[i]=jack_port_register(ac,(String("in")+std::to_string(i)).c_str(),JACK_DEFAULT_AUDIO_TYPE,JackPortIsInput,0);
+      if (ai[i]==NULL) {
+        desc.inChans=i;
+        break;
+      }
+      inBufs[i]=new float[count];
+    }
+  }
+  if (desc.outChans>0) {
+    outBufs=new float*[desc.outChans];
+    iOutBufs=new float*[desc.outChans];
+    ao=new jack_port_t*[desc.outChans];
+    for (int i=0; i<desc.outChans; i++) {
+      ao[i]=jack_port_register(ac,(String("out")+std::to_string(i)).c_str(),JACK_DEFAULT_AUDIO_TYPE,JackPortIsOutput,0);
+      if (ao[i]==NULL) {
+        desc.outChans=i;
+        break;
+      }
+      outBufs[i]=new float[count];
+    }
+  }
+
+  response=desc;
+  initialized=true;
+  return true;
+}
\ No newline at end of file
diff --git a/src/audio/jack.h b/src/audio/jack.h
new file mode 100644
index 000000000..6323b1eab
--- /dev/null
+++ b/src/audio/jack.h
@@ -0,0 +1,26 @@
+#include "taAudio.h"
+#include <jack/jack.h>
+
+class TAAudioJACK: public TAAudio {
+  jack_client_t* ac;
+  jack_port_t** ai;
+  jack_port_t** ao;
+
+  float** iInBufs;
+  float** iOutBufs;
+
+  public:
+    void onSampleRate(jack_nframes_t rate);
+    void onBufferSize(jack_nframes_t bufsize);
+    void onProcess(jack_nframes_t nframes);
+
+    void* getContext();
+    bool quit();
+    bool setRun(bool run);
+    bool init(TAAudioDesc& request, TAAudioDesc& response);
+
+    TAAudioJACK():
+      ac(NULL),
+      ai(NULL),
+      ao(NULL) {}
+};
\ No newline at end of file
diff --git a/src/audio/sdl.cpp b/src/audio/sdl.cpp
new file mode 100644
index 000000000..cd9045588
--- /dev/null
+++ b/src/audio/sdl.cpp
@@ -0,0 +1,86 @@
+#include <string.h>
+#include "sdl.h"
+
+void taSDLProcess(void* inst, unsigned char* buf, int nframes) {
+  TAAudioSDL* in=(TAAudioSDL*)inst;
+  in->onProcess(buf,nframes);
+}
+
+void TAAudioSDL::onProcess(unsigned char* buf, int nframes) {
+  if (audioProcCallback!=NULL) {
+    audioProcCallback(inBufs,outBufs,desc.inChans,desc.outChans,desc.bufsize);
+  }
+  float* fbuf=(float*)buf;
+  for (size_t i=0; i<desc.outChans; i++) {
+    int k=0;
+    for (size_t j=i; j<desc.bufsize*desc.outChans; j+=desc.outChans) {
+      fbuf[j]=outBufs[i][k++];
+    }
+  }
+}
+
+void* TAAudioSDL::getContext() {
+  return (void*)&ac;
+}
+
+bool TAAudioSDL::quit() {
+  if (!initialized) return false;
+
+  SDL_CloseAudioDevice(ai);
+
+  if (running) {
+    running=false;
+  }
+
+  for (int i=0; i<desc.outChans; i++) {
+    delete[] outBufs[i];
+  }
+
+  delete[] outBufs;
+  
+  initialized=false;
+  return true;
+}
+
+bool TAAudioSDL::setRun(bool run) {
+  if (!initialized) return false;
+  SDL_PauseAudioDevice(ai,!run);
+  running=run;
+  return running;
+}
+
+bool TAAudioSDL::init(TAAudioDesc& request, TAAudioDesc& response) {
+  if (initialized) return false;
+  if (SDL_Init(SDL_INIT_AUDIO)<0) return false;
+
+  desc=request;
+  desc.outFormat=TA_AUDIO_FORMAT_F32;
+
+  ac.freq=desc.rate;
+  ac.format=AUDIO_F32;
+  ac.channels=desc.outChans;
+  ac.samples=desc.bufsize;
+  ac.callback=taSDLProcess;
+  ac.userdata=this;
+
+  ai=SDL_OpenAudioDevice(NULL,0,&ac,&ar,SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);
+  if (ai==0) return false;
+
+  desc.name="";
+  desc.rate=ar.freq;
+  desc.inChans=0;
+  desc.outChans=ar.channels;
+  desc.bufsize=ar.samples;
+  desc.fragments=1;
+
+  if (desc.outChans>0) {
+    outBufs=new float*[desc.outChans];
+    for (int i=0; i<desc.outChans; i++) {
+      outBufs[i]=new float[desc.bufsize];
+    }
+  }
+
+  response=desc;
+  initialized=true;
+  return true;
+}
diff --git a/src/audio/sdl.h b/src/audio/sdl.h
new file mode 100644
index 000000000..e9abf9dfa
--- /dev/null
+++ b/src/audio/sdl.h
@@ -0,0 +1,18 @@
+#include "taAudio.h"
+#include <SDL2/SDL.h>
+
+class TAAudioSDL: public TAAudio {
+  SDL_AudioSpec ac, ar;
+  SDL_AudioDeviceID ai;
+
+  float** iInBufs;
+  float** iOutBufs;
+
+  public:
+    void onProcess(unsigned char* buf, int nframes);
+
+    void* getContext();
+    bool quit();
+    bool setRun(bool run);
+    bool init(TAAudioDesc& request, TAAudioDesc& response);
+};
diff --git a/src/audio/taAudio.h b/src/audio/taAudio.h
new file mode 100644
index 000000000..0801932cd
--- /dev/null
+++ b/src/audio/taAudio.h
@@ -0,0 +1,79 @@
+#ifndef _TAAUDIO_H
+#define _TAAUDIO_H
+#include "../ta-utils.h"
+
+struct SampleRateChangeEvent {
+  double rate;
+  SampleRateChangeEvent(double r):
+    rate(r) {}
+};
+
+struct BufferSizeChangeEvent {
+  unsigned int bufsize;
+  BufferSizeChangeEvent(unsigned int bs):
+    bufsize(bs) {}
+};
+
+enum TAAudioFormat {
+  TA_AUDIO_FORMAT_F32=0,
+  TA_AUDIO_FORMAT_F64,
+  TA_AUDIO_FORMAT_U8,
+  TA_AUDIO_FORMAT_S8,
+  TA_AUDIO_FORMAT_U16,
+  TA_AUDIO_FORMAT_S16,
+  TA_AUDIO_FORMAT_U32,
+  TA_AUDIO_FORMAT_S32,
+  TA_AUDIO_FORMAT_U16BE,
+  TA_AUDIO_FORMAT_S16BE,
+  TA_AUDIO_FORMAT_U32BE,
+  TA_AUDIO_FORMAT_S32BE
+};
+
+struct TAAudioDesc {
+  String name;
+  double rate;
+  unsigned int bufsize, fragments;
+  unsigned char inChans, outChans;
+  TAAudioFormat outFormat;
+
+  TAAudioDesc():
+    rate(0.0),
+    bufsize(0),
+    fragments(0),
+    inChans(0),
+    outChans(0),
+    outFormat(TA_AUDIO_FORMAT_F32) {}
+};
+
+class TAAudio {
+  protected:
+    TAAudioDesc desc;
+    TAAudioFormat outFormat;
+    bool running, initialized;
+    float** inBufs;
+    float** outBufs;
+    void (*audioProcCallback)(float**,float**,int,int,unsigned int);
+    void (*sampleRateChanged)(SampleRateChangeEvent);
+    void (*bufferSizeChanged)(BufferSizeChangeEvent);
+  public:
+    void setSampleRateChangeCallback(void (*callback)(SampleRateChangeEvent));
+    void setBufferSizeChangeCallback(void (*callback)(BufferSizeChangeEvent));
+
+    void setCallback(void (*callback)(float**,float**,int,int,unsigned int));
+
+    virtual void* getContext();
+    virtual bool quit();
+    virtual bool setRun(bool run);
+    virtual bool init(TAAudioDesc& request, TAAudioDesc& response);
+
+    TAAudio():
+      outFormat(TA_AUDIO_FORMAT_F32),
+      running(false),
+      initialized(false),
+      inBufs(NULL),
+      outBufs(NULL),
+      audioProcCallback(NULL),
+      sampleRateChanged(NULL),
+      bufferSizeChanged(NULL) {}
+};
+#endif
diff --git a/src/engine/dispatch.h b/src/engine/dispatch.h
new file mode 100644
index 000000000..507d7fc7e
--- /dev/null
+++ b/src/engine/dispatch.h
@@ -0,0 +1,31 @@
+enum DivDispatchCmds {
+  DIV_CMD_NOTE_ON=0,
+  DIV_CMD_NOTE_OFF,
+  DIV_CMD_INSTRUMENT,
+  DIV_CMD_VOLUME,
+  DIV_CMD_PITCH_UP,
+  DIV_CMD_PITCH_DOWN,
+  DIV_CMD_PITCH_TO
+};
+
+struct DivCommand {
+  DivDispatchCmds cmd;
+};
+
+struct DivDelayedCommand {
+  int ticks;
+  DivCommand cmd;
+};
+
+class DivDispatch {
+  public:
+    virtual void acquire(float& l, float& r);
+    virtual int dispatch(DivCommand c);
+
+    /**
+     * initialize this DivDispatch.
+     * @param channels the number of channels to acquire.
+     * @return the number of channels allocated.
+     */
+    virtual int init(int channels);
+};
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
new file mode 100644
index 000000000..bb20de5bc
--- /dev/null
+++ b/src/engine/engine.cpp
@@ -0,0 +1,630 @@
+#include "engine.h"
+#include "safeReader.h"
+#include "../ta-log.h"
+#include "../audio/sdl.h"
+#include <zlib.h>
+
+void process(float** in, float** out, int inChans, int outChans, unsigned int size) {
+  for (int i=0; i<outChans; i++) {
+    for (unsigned int j=0; j<size; j++) {
+      out[i][j]=(float)(j%128)/128.0f;
+    }
+  }
+}
+
+#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;
+}
+
+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;
+
+    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);
+    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.orders.ord[i][j]>ds.ordersLen) {
+          logW("pattern %d exceeds order count %d!\n",ds.orders.ord[i][j],ds.ordersLen);
+        }
+      }
+    }
+
+    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.lp=reader.readC();
+          ins->c64.bp=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();
+        }
+      }
+
+      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=new DivPattern;
+        for (int k=0; k<ds.patLen; k++) {
+          // note
+          pat->data[k][0]=reader.readS();
+          // octave
+          pat->data[k][1]=reader.readS();
+          // volume
+          pat->data[k][3]=reader.readS();
+          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();
+        }
+        chan->data.push_back(pat);
+      }
+      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=0;
+        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()) {
+      logW("premature end of song (we are at %x, but size is %x)\n",reader.tell(),reader.size());
+    }
+
+    song=ds;
+  } catch (EndOfFileException e) {
+    logE("premature end of file!\n");
+    return false;
+  }
+  return true;
+}
+
+void DivEngine::play() {
+  
+}
+
+bool DivEngine::init() {
+  output=new TAAudioSDL;
+  want.bufsize=1024;
+  want.fragments=2;
+  want.inChans=0;
+  want.outChans=2;
+  want.outFormat=TA_AUDIO_FORMAT_F32;
+  want.name="DivAudio";
+
+  output->setCallback(process);
+
+  logI("initializing audio.\n");
+  if (!output->init(want,got)) {
+    logE("error while initializing audio!\n");
+    return false;
+  }
+
+  if (!output->setRun(true)) {
+    printf("error while activating!\n");
+    return false;
+  }
+  return true;
+}
diff --git a/src/engine/engine.h b/src/engine/engine.h
new file mode 100644
index 000000000..23176d343
--- /dev/null
+++ b/src/engine/engine.h
@@ -0,0 +1,35 @@
+#include "song.h"
+#include "dispatch.h"
+#include "../audio/taAudio.h"
+
+struct DivChannelState {
+  std::vector<DivDelayedCommand> delayed;
+  int rampSpeed, portaSpeed, portaNote;
+  int volSpeed;
+  int vibratoDepth, vibratoRate;
+  int tremoloDepth, tremoloRate;
+};
+
+class DivEngine {
+  DivSong song;
+  DivDispatch* dispatch;
+  TAAudio* output;
+  TAAudioDesc want, got;
+  int chans;
+  bool playing;
+  bool speedAB;
+  int ticks, curRow, curOrder;
+  std::vector<DivChannelState> chan;
+
+  public:
+    // load a .dmf.
+    bool load(void* f, size_t length);
+    // save as .dmf.
+    bool save(FILE* f);
+
+    // play
+    void play();
+
+    // initialize the engine.
+    bool init();    
+};
diff --git a/src/engine/instrument.h b/src/engine/instrument.h
new file mode 100644
index 000000000..d72a90193
--- /dev/null
+++ b/src/engine/instrument.h
@@ -0,0 +1,48 @@
+enum DivInstrumentType {
+  DIV_INS_FM,
+  DIV_INS_STD,
+  DIV_INS_GB,
+  DIV_INS_C64
+};
+
+struct DivInstrumentFM {
+  char alg, fb, fms, ams, ops;
+  struct {
+    char am, ar, dr, mult, rr, sl, tl, dt2, rs, dt, d2r, ssgEnv;
+    char dam, dvb, egt, ksl, sus, vib, ws, ksr; // YMU759
+  } op[4];
+};
+
+struct DivInstrumentSTD {
+  int volMacro[256];
+  int arpMacro[256];
+  int dutyMacro[256];
+  int waveMacro[256];
+  bool arpMacroMode;
+  unsigned char volMacroLen, arpMacroLen, dutyMacroLen, waveMacroLen;
+  unsigned char volMacroLoop, arpMacroLoop, dutyMacroLoop, waveMacroLoop;
+};
+
+struct DivInstrumentGB {
+  unsigned char envVol, envDir, envLen, soundLen;
+};
+
+struct DivInstrumentC64 {
+  bool triOn, sawOn, pulseOn, noiseOn;
+  unsigned char a, d, s, r;
+  unsigned char duty;
+  unsigned char ringMod, oscSync;
+  bool toFilter, volIsCutoff, initFilter;
+  unsigned char res, cut;
+  bool hp, lp, bp, ch3off;
+};
+
+struct DivInstrument {
+  String name;
+  bool mode;
+  DivInstrumentType type;
+  DivInstrumentFM fm;
+  DivInstrumentSTD std;
+  DivInstrumentGB gb;
+  DivInstrumentC64 c64;
+};
diff --git a/src/engine/orders.h b/src/engine/orders.h
new file mode 100644
index 000000000..ba2e85829
--- /dev/null
+++ b/src/engine/orders.h
@@ -0,0 +1,3 @@
+struct DivOrders {
+  char ord[32][128];
+};
diff --git a/src/engine/pattern.h b/src/engine/pattern.h
new file mode 100644
index 000000000..a9ce417b7
--- /dev/null
+++ b/src/engine/pattern.h
@@ -0,0 +1,15 @@
+struct DivPattern {
+  char data[256][16];
+};
+
+struct DivChannelData {
+  char effectRows;
+  // data goes as follows: data[ROW][TYPE]
+  // TYPE is:
+  // 0: note
+  // 1: octave
+  // 2: instrument
+  // 3: volume
+  // 4-5+: effect/effect value
+  std::vector<DivPattern*> data;
+};
\ No newline at end of file
diff --git a/src/engine/platform/dummy.cpp b/src/engine/platform/dummy.cpp
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/engine/platform/dummy.h b/src/engine/platform/dummy.h
new file mode 100644
index 000000000..e90013bdb
--- /dev/null
+++ b/src/engine/platform/dummy.h
@@ -0,0 +1,10 @@
+#include "../dispatch.h"
+
+// the dummy platform outputs square waves, interprets STD instruments and plays samples.
+// used when a DivDispatch for a system is not found.
+class DivPlatformDummy: public DivDispatch {
+  public:
+    void acquire(float& l, float& r);
+    int dispatch(DivCommand c);
+    int init(int channels);
+};
\ No newline at end of file
diff --git a/src/engine/safeReader.cpp b/src/engine/safeReader.cpp
new file mode 100644
index 000000000..474efe0cc
--- /dev/null
+++ b/src/engine/safeReader.cpp
@@ -0,0 +1,143 @@
+#include "safeReader.h"
+#include "../ta-log.h"
+
+//#define READ_DEBUG
+
+bool SafeReader::seek(ssize_t where, int whence) {
+  switch (whence) {
+    case SEEK_SET:
+      if (where<0) return false;
+      if (where>(ssize_t)len) return false;
+      curSeek=where;
+      break;
+    case SEEK_CUR: {
+      ssize_t finalSeek=len+where;
+      if (finalSeek<0) return false;
+      if (finalSeek>(ssize_t)len) return false;
+      curSeek=finalSeek;
+      break;
+    }
+    case SEEK_END: {
+      ssize_t finalSeek=len-where;
+      if (finalSeek<0) return false;
+      if (finalSeek>(ssize_t)len) return false;
+      curSeek=finalSeek;
+      break;
+    }
+  }
+  return true;
+}
+
+size_t SafeReader::tell() {
+  return curSeek;
+}
+
+size_t SafeReader::size() {
+  return len;
+}
+
+int SafeReader::read(void* where, size_t count) {
+#ifdef READ_DEBUG
+  logD("SR: reading %d bytes at %x\n",count,curSeek);
+#endif
+  if (count==0) return 0;
+  if (curSeek+count>len) throw EndOfFileException(this,len);
+  memcpy(where,&buf[curSeek],count);
+  curSeek+=count;
+  return count;
+}
+
+char SafeReader::readC() {
+#ifdef READ_DEBUG
+  logD("SR: reading char %x:\n",curSeek);
+#endif
+  if (curSeek+1>len) throw EndOfFileException(this,len);
+#ifdef READ_DEBUG
+  logD("SR: %.2x\n",buf[curSeek]);
+#endif
+  return (signed char)buf[curSeek++];
+}
+
+short SafeReader::readS() {
+#ifdef READ_DEBUG
+  logD("SR: reading short %x:\n",curSeek);
+#endif
+  if (curSeek+2>len) throw EndOfFileException(this,len);
+  short ret=*(short*)(&buf[curSeek]);
+#ifdef READ_DEBUG
+  logD("SR: %.4x\n",ret);
+#endif
+  curSeek+=2;
+  return ret;
+}
+
+short SafeReader::readS_BE() {
+  if (curSeek+1>len) throw EndOfFileException(this,len);
+  short ret=*(short*)(&buf[curSeek]);
+  curSeek+=2;
+  return (ret>>8)|((ret&0xff)<<8);
+}
+
+int SafeReader::readI() {
+#ifdef READ_DEBUG
+  logD("SR: reading int %x:\n",curSeek);
+#endif
+  if (curSeek+4>len) throw EndOfFileException(this,len);
+  int ret=*(int*)(&buf[curSeek]);
+  curSeek+=4;
+#ifdef READ_DEBUG
+  logD("SR: %.8x\n",ret);
+#endif
+  return ret;
+}
+
+int SafeReader::readI_BE() {
+  if (curSeek+4>len) throw EndOfFileException(this,len);
+  int ret=*(int*)(&buf[curSeek]);
+  curSeek+=4;
+  return (ret>>24)|((ret&0xff0000)>>8)|((ret&0xff00)<<8)|((ret&0xff)<<24);
+}
+
+int64_t SafeReader::readL() {
+  if (curSeek+8>len) throw EndOfFileException(this,len);
+  int64_t ret=*(int64_t*)(&buf[curSeek]);
+  curSeek+=8;
+  return ret;
+}
+
+float SafeReader::readF() {
+  if (curSeek+4>len) throw EndOfFileException(this,len);
+  float ret=*(float*)(&buf[curSeek]);
+  curSeek+=4;
+  return ret;
+}
+
+double SafeReader::readD() {
+  if (curSeek+8>len) throw EndOfFileException(this,len);
+  double ret=*(double*)(&buf[curSeek]);
+  curSeek+=8;
+  return ret;
+}
+
+String SafeReader::readString(size_t stlen) {
+  String ret;
+#ifdef READ_DEBUG
+  logD("SR: reading string len %d at %x\n",stlen,curSeek);
+#endif
+  size_t curPos=0;
+  while (curPos<stlen) {
+    char c=readC();
+    if (c!=0) ret.push_back(c);
+    curPos++;
+  }
+  return ret;
+}
+
+String SafeReader::readString() {
+  String ret;
+  char c;
+  while ((c=readC())!=0) {
+    ret.push_back(c);
+  }
+  return ret;
+}
diff --git a/src/engine/safeReader.h b/src/engine/safeReader.h
new file mode 100644
index 000000000..a922f3451
--- /dev/null
+++ b/src/engine/safeReader.h
@@ -0,0 +1,51 @@
+#ifndef _SAFEREADER_H
+#define _SAFEREADER_H
+#include <stdio.h>
+#include <stdlib.h>
+#include "../ta-utils.h"
+
+class SafeReader;
+
+struct EndOfFileException {
+  SafeReader* reader;
+  size_t finalSize;
+  EndOfFileException(SafeReader* r, size_t fs):
+    reader(r),
+    finalSize(fs) {}
+};
+
+class SafeReader {
+  unsigned char* buf;
+  size_t len;
+
+  size_t curSeek;
+
+  public:
+    bool seek(ssize_t where, int whence);
+    size_t tell();
+    size_t size();
+
+    int read(void* where, size_t count);
+
+    // these functions may throw EndOfFileException.
+    char readC();
+    short readS();
+    short readS_BE();
+    int readI();
+    int readI_BE();
+    int64_t readL();
+    int64_t readL_BE();
+    float readF();
+    float readF_BE();
+    double readD();
+    double readD_BE();
+    String readString();
+    String readString(size_t len);
+
+    SafeReader(void* b, size_t l):
+      buf((unsigned char*)b),
+      len(l),
+      curSeek(0) {}
+};
+
+#endif
diff --git a/src/engine/sample.h b/src/engine/sample.h
new file mode 100644
index 000000000..0be271b2a
--- /dev/null
+++ b/src/engine/sample.h
@@ -0,0 +1,7 @@
+struct DivSample {
+  String name;
+  int length, rate;
+  char vol, pitch, depth;
+  short* data;
+  char* data8;
+};
diff --git a/src/engine/song.h b/src/engine/song.h
new file mode 100644
index 000000000..e94d51711
--- /dev/null
+++ b/src/engine/song.h
@@ -0,0 +1,96 @@
+#include <stdio.h>
+#include <vector>
+#include "../ta-utils.h"
+#include "orders.h"
+#include "instrument.h"
+#include "pattern.h"
+#include "wavetable.h"
+#include "sample.h"
+
+enum DivSystem {
+  DIV_SYSTEM_NULL=0,
+  DIV_SYSTEM_YMU759,
+  DIV_SYSTEM_GENESIS,
+  DIV_SYSTEM_GENESIS_EXT,
+  DIV_SYSTEM_SMS,
+  DIV_SYSTEM_GB,
+  DIV_SYSTEM_PCE,
+  DIV_SYSTEM_NES,
+  DIV_SYSTEM_C64_6581,
+  DIV_SYSTEM_C64_8580,
+  DIV_SYSTEM_ARCADE,
+  DIV_SYSTEM_YM2610,
+  DIV_SYSTEM_YM2610_EXT
+};
+
+struct DivSong {
+  // version number used for saving the song.
+  // divorce will save using the latest possible version,
+  // but eventually I will and 0x80 to this value to indicate a divorce module
+  // known version numbers:
+  // - 24: v0.12/0.13/1.0
+  //   - current format version
+  //   - changes pattern length from char to int, probably to allow for size 256
+  // - 23: ???
+  //   - 
+  // - 19: v11
+  //   - introduces Arcade system
+  //   - changes to the FM instrument format due to YMU759 being dropped
+  // - 18: v10
+  //   - radically changes STD instrument for Game Boy
+  // - 17: v9
+  //   - changes C64 volIsCutoff flag from int to char for unknown reasons
+  // - 16: v8 (?)
+  //   - introduces C64 system
+  // - 15: v7 (?)
+  // - 14: v6 (?)
+  //   - introduces NES system
+  //   - changes macro and wave values from char to int
+  // - 13: v5.1
+  //   - introduces PC Engine system in later version (how?)
+  //   - stores highlight in file
+  // - 12: v5 (?)
+  //   - introduces Game Boy system
+  //   - introduces wavetables
+  // - 11: ???
+  //   - introduces Sega Master System
+  //   - custom Hz support
+  //   - instrument type (FM/STD) present
+  //   - prior to this version the instrument type depended on the system
+  // - 10: ???
+  //   - introduces multiple effect columns
+  // - 9: v3.9
+  //   - introduces Genesis system
+  //   - introduces system number
+  // - 7: ???
+  // - 5: ???
+  // - 3: BETA 3 (?)
+  //   - possibly the first version that could save
+  //   - basic format, no system number, 16 instruments, one speed, YMU759-only
+  //   - if somebody manages to find a version 2 or even 1 module, please tell me as it will be worth more than a luxury vehicle
+  unsigned char version;
+
+  // system
+  DivSystem system;
+
+  // song information
+  String name, author;
+
+  // legacy song information
+  String carrier, composer, vendor, category, writer, arranger, copyright, manGroup, manInfo, createdDate, revisionDate;
+
+  // highlight
+  unsigned char hilightA, hilightB;
+
+  // module details
+  unsigned char timeBase, speed1, speed2, arpLen;
+  bool pal;
+  bool customTempo;
+  int hz, patLen, ordersLen, insLen, waveLen, sampleLen;
+
+  DivOrders orders;
+  std::vector<DivInstrument*> ins;
+  std::vector<DivChannelData*> pat;
+  std::vector<DivWavetable*> wave;
+  std::vector<DivSample*> sample;
+};
diff --git a/src/engine/wavetable.h b/src/engine/wavetable.h
new file mode 100644
index 000000000..64fcd9525
--- /dev/null
+++ b/src/engine/wavetable.h
@@ -0,0 +1,4 @@
+struct DivWavetable {
+  int len;
+  int data[32];
+};
diff --git a/src/log.cpp b/src/log.cpp
new file mode 100644
index 000000000..ff0f222ad
--- /dev/null
+++ b/src/log.cpp
@@ -0,0 +1,47 @@
+#include "ta-log.h"
+
+int logD(const char* format, ...) {
+  va_list va;
+  int ret;
+  if (logLevel<LOGLEVEL_DEBUG) return 0;
+  printf("\x1b[1;34m[debug]\x1b[m ");
+  va_start(va,format);
+  ret=vprintf(format,va);
+  va_end(va);
+  fflush(stdout);
+  return ret;
+}
+
+int logI(const char* format, ...) {
+  va_list va;
+  int ret;
+  if (logLevel<LOGLEVEL_INFO) return 0;
+  printf("\x1b[1;32m[info]\x1b[m ");
+  va_start(va,format);
+  ret=vprintf(format,va);
+  va_end(va);
+  return ret;
+}
+
+int logW(const char* format, ...) {
+  va_list va;
+  int ret;
+  if (logLevel<LOGLEVEL_WARN) return 0;
+  printf("\x1b[1;33m[warning]\x1b[m ");
+  va_start(va,format);
+  ret=vprintf(format,va);
+  va_end(va);
+  return ret;
+}
+
+int logE(const char* format, ...) {
+  va_list va;
+  int ret;
+  if (logLevel<LOGLEVEL_ERROR) return 0;
+  printf("\x1b[1;31m[ERROR]\x1b[m ");
+  va_start(va,format);
+  ret=vprintf(format,va);
+  va_end(va);
+  return ret;
+}
+
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 000000000..45cd665e0
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <mutex>
+#include "ta-log.h"
+#include "engine/engine.h"
+
+DivEngine e;
+
+std::mutex m;
+
+int main(int argc, char** argv) {
+  if (argc<2) {
+    logI("usage: %s file\n",argv[0]);
+    return 1;
+  }
+  logI("divorce dev0\n");
+  logI("loading module...\n");
+  FILE* f=fopen(argv[1],"rb");
+  if (f==NULL) {
+    perror("error");
+    return 1;
+  }
+  if (fseek(f,0,SEEK_END)<0) {
+    perror("size error");
+    fclose(f);
+    return 1;
+  }
+  ssize_t len=ftell(f);
+  if (len<1) {
+    if (len==0) {
+      printf("that file is empty!\n");
+    } else {
+      perror("tell error");
+    }
+    fclose(f);
+    return 1;
+  }
+  unsigned char* file=new unsigned char[len];
+  if (fseek(f,0,SEEK_SET)<0) {
+    perror("size error");
+    fclose(f);
+    return 1;
+  }
+  if (fread(file,1,(size_t)len,f)!=(size_t)len) {
+    perror("read error");
+    fclose(f);
+    return 1;
+  }
+  fclose(f);
+  if (!e.load((void*)file,(size_t)len)) {
+    logE("could not open file!\n");
+    return 1;
+  }
+  if (!e.init()) {
+    logE("could not initialize engine!\n");
+    return 1;
+  }
+  logI("loaded! :o\n");
+  while (true) {
+    logI("locking...\n");
+    e.play();
+    m.lock();
+    m.lock();
+  }
+  return 0;
+}
diff --git a/src/ta-log.h b/src/ta-log.h
new file mode 100644
index 000000000..ee5a23b90
--- /dev/null
+++ b/src/ta-log.h
@@ -0,0 +1,17 @@
+#ifndef _TA_LOG_H
+#define _TA_LOG_H
+#include <stdio.h>
+#include <stdarg.h>
+
+#define LOGLEVEL_ERROR 0
+#define LOGLEVEL_WARN 1
+#define LOGLEVEL_INFO 2
+#define LOGLEVEL_DEBUG 3
+
+#define logLevel 3
+
+int logD(const char* format, ...);
+int logI(const char* format, ...);
+int logW(const char* format, ...);
+int logE(const char* format, ...);
+#endif
diff --git a/src/ta-utils.h b/src/ta-utils.h
new file mode 100644
index 000000000..23acd3c5b
--- /dev/null
+++ b/src/ta-utils.h
@@ -0,0 +1,9 @@
+#ifndef _TA_UTILS_H
+#define _TA_UTILS_H
+#include <stdio.h>
+#include <string.h>
+#include <string>
+
+typedef std::string String;
+
+#endif
\ No newline at end of file