path: root/src/base/UMain.pas

{* UltraStar Deluxe - Karaoke Game
 *
 * UltraStar Deluxe is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING. If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *}

unit UMain;

interface

{$IFDEF FPC}
  {$MODE Delphi}
{$ENDIF}

{$I switches.inc}

uses
  SysUtils,
  Classes,
  SDL,
  UMusic,
  URecord,
  UTime,
  UDisplay,
  UIni,
  ULog,
  ULyrics,
  UScreenSing,
  USong,
  gl;

type
  PPLayerNote = ^TPlayerNote;
  TPlayerNote = record
    Start:   integer;
    Length:  integer;
    Detect:  real;    // accurate place, detected in the note
    Tone:    real;
    Perfect: boolean; // true if the note matches the original one, light the star
    Hit:     boolean; // true if the note hits the line
  end;

  PPLayer = ^TPlayer;
  TPlayer = record
    Name:           string;

    // Index in Teaminfo record
    TeamID:         byte;
    PlayerID:       byte;

    // Scores
    Score:          real;
    ScoreLine:      real;
    ScoreGolden:    real;

    ScoreInt:       integer;
    ScoreLineInt:   integer;
    ScoreGoldenInt: integer;
    ScoreTotalInt:  integer;

    // LineBonus
    ScoreLast:      real;    // Last Line Score

    // PerfectLineTwinkle (effect)
    LastSentencePerfect: boolean;

    HighNote:       integer; // index of last note (= High(Note)?)
    LengthNote:     integer; // number of notes (= Length(Note)?).
    Note:           array of TPlayerNote;
  end;

var
  // Absolute Paths
  GamePath:         string;
  SoundPath:        string;
  SongPaths:        TStringList;
  LogPath:          string;
  ThemePath:        string;
  SkinsPath:        string;
  ScreenshotsPath:  string;
  CoverPaths:       TStringList;
  LanguagesPath:    string;
  PluginPath:       string;
  VisualsPath:      string;
  FontPath:         string;
  ResourcesPath:    string;
  PlayListPath:     string;

  Done:             boolean;
  // FIXME: ConversionFileName should not be global
  ConversionFileName: string;
  Restart:            boolean;

  // player and music info
  Player:      array of TPlayer;
  PlayersPlay: integer;

  CurrentSong: TSong;

const
  MAX_SONG_SCORE = 10000;     // max. achievable points per song
  MAX_SONG_LINE_BONUS = 1000; // max. achievable line bonus per song

function FindPath(out PathResult: string; const RequestedPath: string; NeedsWritePermission: boolean): boolean;
procedure InitializePaths;
procedure AddSongPath(const Path: string);

procedure Main;
procedure MainLoop;
procedure CheckEvents;
procedure Sing(Screen: TScreenSing);
procedure NewSentence(Screen: TScreenSing);
procedure NewBeatClick(Screen: TScreenSing);  // executed when on then new beat for click
procedure NewBeatDetect(Screen: TScreenSing); // executed when on then new beat for detection
procedure NewNote(Screen: TScreenSing);       // detect note
function  GetMidBeat(Time: real): real;
function  GetTimeFromBeat(Beat: integer): real;
procedure ClearScores(PlayerNum: integer);

type
  TMainThreadExecProc = procedure(Data: Pointer);

const
  MAINTHREAD_EXEC_EVENT = SDL_USEREVENT + 2;

{*
 * Delegates execution of procedure Proc to the main thread.
 * The Data pointer is passed to the procedure when it is called.
 * The main thread is notified by signaling a MAINTHREAD_EXEC_EVENT which
 * is handled in CheckEvents.
 * Note that Data must not be a pointer to local data. If you want to pass local
 * data, use Getmem() or New() or create a temporary object.
 *}
procedure MainThreadExec(Proc: TMainThreadExecProc; Data: Pointer);

implementation

uses
  Math,
  StrUtils,
  USongs,
  UJoystick,
  UCommandLine,
  ULanguage,
  //SDL_ttf,
  USkins,
  UCovers,
  UCatCovers,
  UDataBase,
  UPlaylist,
  UDLLManager,
  UParty,
  UConfig,
  UCore,
  UCommon,
  UGraphic,
  UGraphicClasses,
  UPluginDefs,
  UPlatform,
  UThemes;

procedure Main;
var
  WindowTitle: string;
begin
  {$IFNDEF Debug}
  try
  {$ENDIF}
    WindowTitle := USDXVersionStr;

    Platform.Init;

    if Platform.TerminateIfAlreadyRunning(WindowTitle) then
      Exit;

    // fix floating-point exceptions (FPE)
    DisableFloatingPointExceptions();
    // fix the locale for string-to-float parsing in C-libs
    SetDefaultNumericLocale();

    // setup separators for parsing
    // Note: ThousandSeparator must be set because of a bug in TIniFile.ReadFloat
    ThousandSeparator := ',';
    DecimalSeparator := '.';

    //------------------------------
    // StartUp - Create Classes and Load Files
    //------------------------------

    // initialize SDL
    // without SDL_INIT_TIMER SDL_GetTicks() might return strange values
    SDL_Init(SDL_INIT_VIDEO or SDL_INIT_TIMER);
    SDL_EnableUnicode(1);

    USTime := TTime.Create;
    VideoBGTimer := TRelativeTimer.Create;

    // Commandline Parameter Parser
    Params := TCMDParams.Create;

    // Log + Benchmark
    Log := TLog.Create;
    Log.Title := WindowTitle;
    Log.FileOutputEnabled := not Params.NoLog;
    Log.BenchmarkStart(0);

    // Language
    Log.BenchmarkStart(1);
    Log.LogStatus('Initialize Paths', 'Initialization');
    InitializePaths;
    Log.LogStatus('Load Language', 'Initialization');
    Language := TLanguage.Create;

    // add const values:
    Language.AddConst('US_VERSION', USDXVersionStr);
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Language', 1);

    {
    // SDL_ttf (Not used yet, maybe in version 1.5)
    Log.BenchmarkStart(1);
    Log.LogStatus('Initialize SDL_ttf', 'Initialization');
    TTF_Init();
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Initializing SDL_ttf', 1);
    }

    // Skin
    Log.BenchmarkStart(1);
    Log.LogStatus('Loading Skin List', 'Initialization');
    Skin := TSkin.Create;
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Skin List', 1);

    // Ini + Paths
    Log.BenchmarkStart(1);
    Log.LogStatus('Load Ini', 'Initialization');
    Ini := TIni.Create;
    Ini.Load;

    //it's possible that this is the first run, create a .ini file if neccessary
    Log.LogStatus('Write Ini', 'Initialization');
    Ini.Save;

    // Load Languagefile
    if (Params.Language <> -1) then
      Language.ChangeLanguage(ILanguage[Params.Language])
    else
      Language.ChangeLanguage(ILanguage[Ini.Language]);

    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Ini', 1);

    // Sound
    Log.BenchmarkStart(1);
    Log.LogStatus('Initialize Sound', 'Initialization');
    InitializeSound();
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Initializing Sound', 1);

    // Lyrics-engine with media reference timer
    LyricsState := TLyricsState.Create();

    // Theme
    Log.BenchmarkStart(1);
    Log.LogStatus('Load Themes', 'Initialization');
    Theme := TTheme.Create(ThemePath + ITheme[Ini.Theme] + '.ini', Ini.Color);
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Themes', 1);

    // Covers Cache
    Log.BenchmarkStart(1);
    Log.LogStatus('Creating Covers Cache', 'Initialization');
    Covers := TCoverDatabase.Create;
    Log.LogBenchmark('Loading Covers Cache Array', 1);
    Log.BenchmarkStart(1);

    // Category Covers
    Log.BenchmarkStart(1);
    Log.LogStatus('Creating Category Covers Array', 'Initialization');
    CatCovers:= TCatCovers.Create;
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Category Covers Array', 1);

    // Songs
    //Log.BenchmarkStart(1);
    Log.LogStatus('Creating Song Array', 'Initialization');
    Songs := TSongs.Create;
    //Songs.LoadSongList;

    Log.LogStatus('Creating 2nd Song Array', 'Initialization');
    CatSongs := TCatSongs.Create;

    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Songs', 1);

    // PluginManager
    Log.BenchmarkStart(1);
    Log.LogStatus('PluginManager', 'Initialization');
    DLLMan := TDLLMan.Create;   // Load PluginList
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading PluginManager', 1);

    {// Party Mode Manager
    Log.BenchmarkStart(1);
    Log.LogStatus('PartySession Manager', 'Initialization');
    PartySession := TPartySession.Create;   //Load PartySession

    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading PartySession Manager', 1);      }

    // Graphics
    Log.BenchmarkStart(1);
    Log.LogStatus('Initialize 3D', 'Initialization');
    Initialize3D(WindowTitle);
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Initializing 3D', 1);

    // Score Saving System
    Log.BenchmarkStart(1);
    Log.LogStatus('DataBase System', 'Initialization');
    DataBase := TDataBaseSystem.Create;

    if (Params.ScoreFile = '') then
      DataBase.Init (Platform.GetGameUserPath + 'Ultrastar.db')
    else
      DataBase.Init (Params.ScoreFile);

    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading DataBase System', 1);

    // Playlist Manager
    Log.BenchmarkStart(1);
    Log.LogStatus('Playlist Manager', 'Initialization');
    PlaylistMan := TPlaylistManager.Create;
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Playlist Manager', 1);

    // GoldenStarsTwinkleMod
    Log.BenchmarkStart(1);
    Log.LogStatus('Effect Manager', 'Initialization');
    GoldenRec := TEffectManager.Create;
    Log.BenchmarkEnd(1);
    Log.LogBenchmark('Loading Particle System', 1);

    // Joypad
    if (Ini.Joypad = 1) or (Params.Joypad) then
    begin
      Log.BenchmarkStart(1);
      Log.LogStatus('Initialize Joystick', 'Initialization');
      Joy := TJoy.Create;
      Log.BenchmarkEnd(1);
      Log.LogBenchmark('Initializing Joystick', 1);
    end;

    Log.BenchmarkEnd(0);
    Log.LogBenchmark('Loading Time', 0);

    Log.LogStatus('Creating Core', 'Initialization');
    {Core := TCore.Create(
      USDXShortVersionStr,
      MakeVersion(USDX_VERSION_MAJOR,
                  USDX_VERSION_MINOR,
                  USDX_VERSION_RELEASE,
                  chr(0))
    );  }

    Log.LogStatus('Running Core', 'Initialization');
    //Core.Run;

    //------------------------------
    // Start Mainloop
    //------------------------------
    Log.LogStatus('Main Loop', 'Initialization');
    MainLoop;

  {$IFNDEF Debug}
  finally
  {$ENDIF}
    //------------------------------
    // Finish Application
    //------------------------------

    // TODO:
    // call an uninitialize routine for every initialize step
    // or at least use the corresponding Free methods

    FinalizeMedia();

    //TTF_Quit();
    SDL_Quit();

    if assigned(Log) then
    begin
      Log.LogStatus('Main Loop', 'Finished');
      Log.Free;
    end;
  {$IFNDEF Debug}
  end;
  {$ENDIF}
end;

procedure MainLoop;
var
  Delay: integer;
const
  MAX_FPS = 100;
begin
  SDL_EnableKeyRepeat(125, 125);

  CountSkipTime();  // JB - for some reason this seems to be needed when we use the SDL Timer functions.
  while not Done do
  begin
    // joypad
    if (Ini.Joypad = 1) or (Params.Joypad) then
      Joy.Update;

    // keyboard events
    CheckEvents;

    // display
    done := not Display.Draw;
    SwapBuffers;

    // delay
    CountMidTime;

    Delay := Floor(1000 / MAX_FPS - 1000 * TimeMid);

    if Delay >= 1 then
      SDL_Delay(Delay); // dynamic, maximum is 100 fps

    CountSkipTime;

    // reinitialization of graphics
    if Restart then
    begin
      Reinitialize3D;
      Restart := false;
    end;

  end;
end;

procedure CheckEvents;
var
  Event: TSDL_event;
begin
  if Assigned(Display.NextScreen) then
    Exit;

  while (SDL_PollEvent(@Event) <> 0) do
  begin
    case Event.type_ of
      SDL_QUITEV:
      begin
        Display.Fade := 0;
        Display.NextScreenWithCheck := nil;
        Display.CheckOK := true;
      end;
      SDL_MOUSEBUTTONDOWN:
      begin
      {
        with Event.button do
        begin
          if State = SDL_BUTTON_LEFT Then
          begin
            //
          end;
        end;
      }
      end;
      SDL_VIDEORESIZE:
      begin
        ScreenW := Event.resize.w;
        ScreenH := Event.resize.h;
        // Note: do NOT call SDL_SetVideoMode on Windows and MacOSX here.
        // This would create a new OpenGL render-context and all texture data
        // would be invalidated.
        // On Linux the mode MUST be resetted, otherwise graphics will be corrupted.
        {$IF Defined(Linux) or Defined(FreeBSD)}
        if boolean( Ini.FullScreen ) then
          SDL_SetVideoMode(ScreenW, ScreenH, (Ini.Depth+1) * 16, SDL_OPENGL or SDL_FULLSCREEN)
        else
          SDL_SetVideoMode(ScreenW, ScreenH, (Ini.Depth+1) * 16, SDL_OPENGL or SDL_RESIZABLE);
        {$IFEND}
      end;
      SDL_KEYDOWN:
        begin
          // remap the "keypad enter" key to the "standard enter" key
          if (Event.key.keysym.sym = SDLK_KP_ENTER) then
            Event.key.keysym.sym := SDLK_RETURN;

          if (Event.key.keysym.sym = SDLK_F11) or
             ((Event.key.keysym.sym = SDLK_RETURN) and
              ((Event.key.keysym.modifier and KMOD_ALT) <> 0)) then // toggle full screen
          begin
            Ini.FullScreen := integer( not boolean( Ini.FullScreen ) );

            // FIXME: SDL_SetVideoMode creates a new OpenGL RC so we have to
            // reload all texture data (-> whitescreen bug).
            // Only Linux (and FreeBSD) is able to handle screen-switching this way.
            {$IF Defined(Linux) or Defined(FreeBSD)}
            if boolean( Ini.FullScreen ) then
            begin
              SDL_SetVideoMode(ScreenW, ScreenH, (Ini.Depth+1) * 16, SDL_OPENGL or SDL_FULLSCREEN);
              SDL_ShowCursor(0);
            end
            else
            begin
              SDL_SetVideoMode(ScreenW, ScreenH, (Ini.Depth+1) * 16, SDL_OPENGL or SDL_RESIZABLE);
              SDL_ShowCursor(1);
            end;

            glViewPort(0, 0, ScreenW, ScreenH);
            {$IFEND}
          end
          // if print is pressed -> make screenshot and save to screenshot path
          else if (Event.key.keysym.sym = SDLK_SYSREQ) or (Event.key.keysym.sym = SDLK_PRINT) then
            Display.SaveScreenShot
          // if there is a visible popup then let it handle input instead of underlying screen
          // shoud be done in a way to be sure the topmost popup has preference (maybe error, then check)
          else if (ScreenPopupError <> nil) and (ScreenPopupError.Visible) then
            done := not ScreenPopupError.ParseInput(Event.key.keysym.sym, WideChar(Event.key.keysym.unicode), true)
          else if (ScreenPopupCheck <> nil) and (ScreenPopupCheck.Visible) then
            done := not ScreenPopupCheck.ParseInput(Event.key.keysym.sym, WideChar(Event.key.keysym.unicode), true)
          else
          begin
            // check if screen wants to exit
            done := not Display.CurrentScreen^.ParseInput(Event.key.keysym.sym, WideChar(Event.key.keysym.unicode), true);

            // if screen wants to exit
            if done then
            begin
              // if question option is enabled then show exit popup
              if (Ini.AskbeforeDel = 1) then
              begin
                Display.CurrentScreen^.CheckFadeTo(nil,'MSG_QUIT_USDX');
              end
              else // if ask-for-exit is disabled then simply exit
              begin
                Display.Fade := 0;
                Display.NextScreenWithCheck := nil;
                Display.CheckOK := true;
              end;
            end;

          end;
        end;
      SDL_JOYAXISMOTION:
        begin
          // not implemented
        end;
      SDL_JOYBUTTONDOWN:
        begin
          // not implemented
        end;
      MAINTHREAD_EXEC_EVENT:
        with Event.user do
        begin
          TMainThreadExecProc(data1)(data2);
        end;
    end; // case
  end; // while
end;

procedure MainThreadExec(Proc: TMainThreadExecProc; Data: Pointer);
var
  Event: TSDL_Event;
begin
  with Event.user do
  begin
    type_ := MAINTHREAD_EXEC_EVENT;
    code  := 0;     // not used at the moment
    data1 := @Proc;
    data2 := Data;
  end;
  SDL_PushEvent(@Event);
end;

function GetTimeForBeats(BPM, Beats: real): real;
begin
  Result := 60 / BPM * Beats;
end;

function GetBeats(BPM, msTime: real): real;
begin
  Result := BPM * msTime / 60;
end;

procedure GetMidBeatSub(BPMNum: integer; var Time: real; var CurBeat: real);
var
  NewTime: real;
begin
  if High(CurrentSong.BPM) = BPMNum then
  begin
    // last BPM
    CurBeat := CurrentSong.BPM[BPMNum].StartBeat + GetBeats(CurrentSong.BPM[BPMNum].BPM, Time);
    Time := 0;
  end
  else
  begin
    // not last BPM
    // count how much time is it for start of the new BPM and store it in NewTime
    NewTime := GetTimeForBeats(CurrentSong.BPM[BPMNum].BPM, CurrentSong.BPM[BPMNum+1].StartBeat - CurrentSong.BPM[BPMNum].StartBeat);

    // compare it to remaining time
    if (Time - NewTime) > 0 then
    begin
      // there is still remaining time
      CurBeat := CurrentSong.BPM[BPMNum].StartBeat;
      Time := Time - NewTime;
    end
    else
    begin
      // there is no remaining time
      CurBeat := CurrentSong.BPM[BPMNum].StartBeat + GetBeats(CurrentSong.BPM[BPMNum].BPM, Time);
      Time := 0;
    end; // if
  end; // if
end;

function GetMidBeat(Time: real): real;
var
  CurBeat: real;
  CurBPM:  integer;
begin
  // static BPM
  if Length(CurrentSong.BPM) = 1 then
  begin
    Result := Time * CurrentSong.BPM[0].BPM / 60;
  end
  // variable BPM
  else if Length(CurrentSong.BPM) > 1 then
  begin
    CurBeat := 0;
    CurBPM := 0;
    while (Time > 0) do
    begin
      GetMidBeatSub(CurBPM, Time, CurBeat);
      Inc(CurBPM);
    end;

    Result := CurBeat;
  end
  // invalid BPM
  else
  begin
    Result := 0;
  end;
end;

function GetTimeFromBeat(Beat: integer): real;
var
  CurBPM: integer;
begin
  // static BPM
  if Length(CurrentSong.BPM) = 1 then
  begin
    Result := CurrentSong.GAP / 1000 + Beat * 60 / CurrentSong.BPM[0].BPM;
  end
  // variable BPM
  else if Length(CurrentSong.BPM) > 1 then
  begin
    Result := CurrentSong.GAP / 1000;
    CurBPM := 0;
    while (CurBPM <= High(CurrentSong.BPM)) and
          (Beat > CurrentSong.BPM[CurBPM].StartBeat) do
    begin
      if (CurBPM < High(CurrentSong.BPM)) and
         (Beat >= CurrentSong.BPM[CurBPM+1].StartBeat) then
      begin
        // full range
        Result := Result + (60 / CurrentSong.BPM[CurBPM].BPM) *
                           (CurrentSong.BPM[CurBPM+1].StartBeat - CurrentSong.BPM[CurBPM].StartBeat);
      end;

      if (CurBPM = High(CurrentSong.BPM)) or
         (Beat < CurrentSong.BPM[CurBPM+1].StartBeat) then
      begin
        // in the middle
        Result := Result + (60 / CurrentSong.BPM[CurBPM].BPM) *
                           (Beat - CurrentSong.BPM[CurBPM].StartBeat);
      end;
      Inc(CurBPM);
    end;

    {
    while (Time > 0) do
    begin
      GetMidBeatSub(CurBPM, Time, CurBeat);
      Inc(CurBPM);
    end;
    }
  end
  // invalid BPM
  else
  begin
    Result := 0;
  end;
end;

procedure Sing(Screen: TScreenSing);
var
  Count:   integer;
  CountGr: integer;
  CP:      integer;
  N:       integer;
begin
  LyricsState.UpdateBeats();

  // sentences routines
  for CountGr := 0 to 0 do //High(Lines)
  begin;
    CP := CountGr;
    // old parts
    LyricsState.OldLine := Lines[CP].Current;

    // choose current parts
    for Count := 0 to Lines[CP].High do
    begin
      if LyricsState.CurrentBeat >= Lines[CP].Line[Count].Start then
        Lines[CP].Current := Count;
    end;

    // clean player note if there is a new line
    // (optimization on halfbeat time)
    if Lines[CP].Current <> LyricsState.OldLine then
      NewSentence(Screen);

  end; // for CountGr

  // make some operations on clicks
  if {(LyricsState.CurrentBeatC >= 0) and }(LyricsState.OldBeatC <> LyricsState.CurrentBeatC) then
    NewBeatClick(Screen);

  // make some operations when detecting new voice pitch
  if (LyricsState.CurrentBeatD >= 0) and (LyricsState.OldBeatD <> LyricsState.CurrentBeatD) then
    NewBeatDetect(Screen);
end;

procedure NewSentence(Screen: TScreenSing);
var
  i: integer;
begin
  // clean note of player
  for i := 0 to High(Player) do
  begin
    Player[i].LengthNote := 0;
    Player[i].HighNote := -1;
    SetLength(Player[i].Note, 0);
  end;

  // on sentence change...
  Screen.onSentenceChange(Lines[0].Current);
end;

procedure NewBeatClick;
var
  Count: integer;
begin
  // beat click
  if ((Ini.BeatClick = 1) and
      ((LyricsState.CurrentBeatC + Lines[0].Resolution + Lines[0].NotesGAP) mod Lines[0].Resolution = 0)) then
  begin
    AudioPlayback.PlaySound(SoundLib.Click);
  end;

  for Count := 0 to Lines[0].Line[Lines[0].Current].HighNote do
  begin
    if (Lines[0].Line[Lines[0].Current].Note[Count].Start = LyricsState.CurrentBeatC) then
    begin
      // click assist
      if Ini.ClickAssist = 1 then
        AudioPlayback.PlaySound(SoundLib.Click);

      // drum machine
      (*
      TempBeat := LyricsState.CurrentBeat; // + 2;
      if (TempBeat mod 8 = 0) then Music.PlayDrum;
      if (TempBeat mod 8 = 4) then Music.PlayClap;
      //if (TempBeat mod 4 = 2) then Music.PlayHihat;
      if (TempBeat mod 4 <> 0) then Music.PlayHihat;
      *)
    end;
  end;
end;

procedure NewBeatDetect(Screen: TScreenSing);
begin
  NewNote(Screen);
end;

procedure NewNote(Screen: TScreenSing);
var
  LineFragmentIndex:   integer;
  CurrentLineFragment: PLineFragment;
  PlayerIndex:         integer;
  CurrentSound:        TCaptureBuffer;
  CurrentPlayer:       PPlayer;
  LastPlayerNote:      PPlayerNote;
  Line: 	       PLine;
  SentenceIndex:       integer;
  SentenceMin:         integer;
  SentenceMax:         integer;
  SentenceDetected:    integer; // sentence of detected note
  NoteAvailable:       boolean;
  NewNote:             boolean;
  Range:               integer;
  NoteHit:             boolean;
  MaxSongPoints:       integer; // max. points for the song (without line bonus)
  MaxLinePoints:       real;    // max. points for the current line
  ScoreFactor:         array[TNoteType] of integer;
begin
  ScoreFactor[ntFreestyle] := 0;
  ScoreFactor[ntNormal]    := 1;
  ScoreFactor[ntGolden]    := 2;
  // TODO: add duet mode support
  // use Lines[LineSetIndex] with LineSetIndex depending on the current player

  // count min and max sentence range for checking 
  // (detection is delayed to the notes we see on the screen)
  SentenceMin := Lines[0].Current-1;
  if (SentenceMin < 0) then
    SentenceMin := 0;
  SentenceMax := Lines[0].Current;

  // check for an active note at the current time defined in the lyrics
  NoteAvailable := false;
  SentenceDetected := SentenceMin;
  for SentenceIndex := SentenceMin to SentenceMax do
  begin
    Line := @Lines[0].Line[SentenceIndex];
    for LineFragmentIndex := 0 to Line.HighNote do
    begin
      CurrentLineFragment := @Line.Note[LineFragmentIndex];
      // check if line is active
      if ((CurrentLineFragment.Start <= LyricsState.CurrentBeatD) and
          (CurrentLineFragment.Start + CurrentLineFragment.Length-1 >= LyricsState.CurrentBeatD)) and
         (CurrentLineFragment.NoteType <> ntFreestyle) and       // but ignore FreeStyle notes
         (CurrentLineFragment.Length > 0) then                   // and make sure the note length is at least 1
      begin
        SentenceDetected := SentenceIndex;
        NoteAvailable := true;
        Break;
      end;
    end;
    // TODO: break here, if NoteAvailable is true? We would then use the first instead
    // of the last note matching the current beat if notes overlap. But notes
    // should not overlap at all.
    // if (NoteAvailable) then
    //  Break;
  end;

  // analyze player signals
  for PlayerIndex := 0 to PlayersPlay-1 do
  begin
    CurrentPlayer := @Player[PlayerIndex];
    CurrentSound := AudioInputProcessor.Sound[PlayerIndex];

    // at the beginning of the song there is no previous note
    if (Length(CurrentPlayer.Note) > 0) then
      LastPlayerNote := @CurrentPlayer.Note[CurrentPlayer.HighNote]
    else
      LastPlayerNote := nil;

    // analyze buffer
    CurrentSound.AnalyzeBuffer;

    // add some noise
    // TODO: do we need this?
    //LyricsState.Tone := LyricsState.Tone + Round(Random(3)) - 1;

    // add note if possible
    if (CurrentSound.ToneValid and NoteAvailable) then
    begin
      Line := @Lines[0].Line[SentenceDetected];

      // process until last note
      for LineFragmentIndex := 0 to Line.HighNote do
      begin
        CurrentLineFragment := @Line.Note[LineFragmentIndex];
        if (CurrentLineFragment.Start <= LyricsState.OldBeatD+1) and
           (CurrentLineFragment.Start + CurrentLineFragment.Length > LyricsState.OldBeatD+1) then
        begin
          // compare notes (from song-file and from player)

          // move players tone to proper octave
          while (CurrentSound.Tone - CurrentLineFragment.Tone > 6) do
            CurrentSound.Tone := CurrentSound.Tone - 12;

          while (CurrentSound.Tone - CurrentLineFragment.Tone < -6) do
            CurrentSound.Tone := CurrentSound.Tone + 12;

          // half size notes patch
          NoteHit := false;

          // if Ini.Difficulty = 0 then Range := 2;
          // if Ini.Difficulty = 1 then Range := 1;
          // if Ini.Difficulty = 2 then Range := 0;
          Range := 2 - Ini.Difficulty;

          // check if the player hit the correct tone within the tolerated range
          if (Abs(CurrentLineFragment.Tone - CurrentSound.Tone) <= Range) then
          begin
            // adjust the players tone to the correct one
            // TODO: do we need to do this?
            CurrentSound.Tone := CurrentLineFragment.Tone;

            // half size notes patch
            NoteHit := true;

            if (Ini.LineBonus > 0) then
              MaxSongPoints := MAX_SONG_SCORE - MAX_SONG_LINE_BONUS
            else
              MaxSongPoints := MAX_SONG_SCORE;

            // Note: ScoreValue is the sum of all note values of the song
            MaxLinePoints := MaxSongPoints / Lines[0].ScoreValue * ScoreFactor[CurrentLineFragment.NoteType];

            // FIXME: is this correct? Why do we add the points for a whole line
            // if just one note is correct?
            case CurrentLineFragment.NoteType of
              ntNormal: CurrentPlayer.Score       := CurrentPlayer.Score       + MaxLinePoints;
              ntGolden: CurrentPlayer.ScoreGolden := CurrentPlayer.ScoreGolden + MaxLinePoints;
            end;

            CurrentPlayer.ScoreInt := Floor(CurrentPlayer.Score / 10) * 10;
            CurrentPlayer.ScoreGoldenInt := Floor(CurrentPlayer.ScoreGolden / 10) * 10;

            CurrentPlayer.ScoreTotalInt := CurrentPlayer.ScoreInt +
                                           CurrentPlayer.ScoreGoldenInt +
                                           CurrentPlayer.ScoreLineInt;
          end;

        end; // operation
      end; // for

      // check if we have to add a new note or extend the note's length
      if (SentenceDetected = SentenceMax) then
      begin
        // we will add a new note
        NewNote := true;

        // if previous note (if any) was the same, extend previous note
        if ((CurrentPlayer.LengthNote > 0) and
            (LastPlayerNote <> nil) and
            (LastPlayerNote.Tone = CurrentSound.Tone) and
            ((LastPlayerNote.Start + LastPlayerNote.Length) = LyricsState.CurrentBeatD)) then
        begin
          NewNote := false;
        end;

        // if is not as new note to control
        for LineFragmentIndex := 0 to Line.HighNote do
        begin
          if (Line.Note[LineFragmentIndex].Start = LyricsState.CurrentBeatD) then
            NewNote := true;
        end;

        // add new note
        if NewNote then
        begin
          // new note
          Inc(CurrentPlayer.LengthNote);
          Inc(CurrentPlayer.HighNote);
          SetLength(CurrentPlayer.Note, CurrentPlayer.LengthNote);

          // update player's last note
          LastPlayerNote := @CurrentPlayer.Note[CurrentPlayer.HighNote];
          with LastPlayerNote^ do
          begin
            Start  := LyricsState.CurrentBeatD;
            Length := 1;
            Tone   := CurrentSound.Tone; // Tone || ToneAbs
            Detect := LyricsState.MidBeat;
            Hit    := NoteHit; // half note patch
          end;
        end
        else
        begin
          // extend note length
          if (LastPlayerNote <> nil) then
            Inc(LastPlayerNote.Length);
        end;

        // check for perfect note and then light the star (on Draw)
        for LineFragmentIndex := 0 to Line.HighNote do
        begin
          CurrentLineFragment := @Line.Note[LineFragmentIndex];
          if (CurrentLineFragment.Start  = LastPlayerNote.Start) and
             (CurrentLineFragment.Length = LastPlayerNote.Length) and
             (CurrentLineFragment.Tone   = LastPlayerNote.Tone) then
          begin
            LastPlayerNote.Perfect := true;
          end;
        end;
      end; // if SentenceDetected = SentenceMax

    end; // if Detected
  end; // for PlayerIndex

  //Log.LogStatus('EndBeat', 'NewBeat');

  // on sentence end -> for LineBonus and display of SingBar (rating pop-up)
  if (SentenceDetected >= Low(Lines[0].Line)) and
     (SentenceDetected <= High(Lines[0].Line)) then
  begin
    Line := @Lines[0].Line[SentenceDetected];
    CurrentLineFragment := @Line.Note[Line.HighNote];
    if ((CurrentLineFragment.Start + CurrentLineFragment.Length - 1) = LyricsState.CurrentBeatD) then
    begin
      if assigned(Screen) then
        Screen.OnSentenceEnd(SentenceDetected);
    end;
  end;

end;

procedure ClearScores(PlayerNum: integer);
begin
  with Player[PlayerNum] do
  begin
    Score          := 0;
    ScoreLine      := 0;
    ScoreGolden    := 0;

    ScoreInt       := 0;
    ScoreLineInt   := 0;
    ScoreGoldenInt := 0;
    ScoreTotalInt  := 0;

    ScoreLast      := 0;

    LastSentencePerfect := false;
  end;
end;

procedure AddSpecialPath(var PathList: TStringList; const Path: string);
var
  I: integer;
  PathAbs, OldPathAbs: string;
begin
  if (PathList = nil) then
    PathList := TStringList.Create;

  if (Path = '') or not ForceDirectories(Path) then
    Exit;

  PathAbs := IncludeTrailingPathDelimiter(ExpandFileName(Path));

  // check if path or a part of the path was already added
  for I := 0 to PathList.Count-1 do
  begin
    OldPathAbs := IncludeTrailingPathDelimiter(ExpandFileName(PathList[I]));
    // check if the new directory is a sub-directory of a previously added one.
    // This is also true, if both paths point to the same directories.
    if (AnsiStartsText(OldPathAbs, PathAbs)) then
    begin
      // ignore the new path
      Exit;
    end;

    // check if a previously added directory is a sub-directory of the new one.
    if (AnsiStartsText(PathAbs, OldPathAbs)) then
    begin
      // replace the old with the new one.
      PathList[I] := PathAbs;
      Exit;
    end;
  end;

  PathList.Add(PathAbs);
end;

procedure AddSongPath(const Path: string);
begin
  AddSpecialPath(SongPaths, Path);
end;

procedure AddCoverPath(const Path: string);
begin
  AddSpecialPath(CoverPaths, Path);
end;

(**
 * Initialize a path variable
 * After setting paths, make sure that paths exist
 *)
function FindPath(out PathResult: string; const RequestedPath: string; NeedsWritePermission: boolean): boolean;
begin
  Result := false;

  if (RequestedPath = '') then
    Exit;

  // Make sure the directory exists
  if (not ForceDirectories(RequestedPath)) then
  begin
    PathResult := '';
    Exit;
  end;

  PathResult := IncludeTrailingPathDelimiter(RequestedPath);

  if (NeedsWritePermission) and
     (FileIsReadOnly(RequestedPath)) then
  begin
    Exit;
  end;

  Result := true;
end;

(**
 * Function sets all absolute paths e.g. song path and makes sure the directorys exist
 *)
procedure InitializePaths;
begin
  // Log directory (must be writable)
  if (not FindPath(LogPath, Platform.GetLogPath, true)) then
  begin
    Log.FileOutputEnabled := false;
    Log.LogWarn('Log directory "'+ Platform.GetLogPath +'" not available', 'InitializePaths');
  end;

  FindPath(SoundPath,        Platform.GetGameSharedPath + 'sounds', false);
  FindPath(ThemePath,        Platform.GetGameSharedPath + 'themes', false);
  FindPath(SkinsPath,        Platform.GetGameSharedPath + 'themes', false);
  FindPath(LanguagesPath,    Platform.GetGameSharedPath + 'languages', false);
  FindPath(PluginPath,       Platform.GetGameSharedPath + 'plugins', false);
  FindPath(VisualsPath,      Platform.GetGameSharedPath + 'visuals', false);
  FindPath(FontPath,         Platform.GetGameSharedPath + 'fonts', false);
  FindPath(ResourcesPath,    Platform.GetGameSharedPath + 'resources', false);

  // Playlists are not shared as we need one directory to write too
  FindPath(PlaylistPath, Platform.GetGameUserPath + 'playlists', true);

  // Screenshot directory (must be writable)
  if (not FindPath(ScreenshotsPath,  Platform.GetGameUserPath + 'screenshots', true)) then
  begin
    Log.LogWarn('Screenshot directory "'+ Platform.GetGameUserPath +'" not available', 'InitializePaths');
  end;

  // Add song paths
  AddSongPath(Params.SongPath);
  AddSongPath(Platform.GetGameSharedPath + 'songs');
  AddSongPath(Platform.GetGameUserPath + 'songs');

  // Add category cover paths
  AddCoverPath(Platform.GetGameSharedPath + 'covers');
  AddCoverPath(Platform.GetGameUserPath + 'covers');
end;

end.