Zwei Werte [0..16] in einem Integer festhalten

[himitsu]

Notfalls hätte ich noch etwas:

Delphi-Quellcode:

Var P: TIntegerPack; 

P.Clear;
P.Add(MIN_X, MAX_X, X);
P.Add(MIN_Y, MAX_Y, Y);
i := P.Result;

P.Clear;
P.Add(MIN_X, MAX_X);
P.Add(MIN_Y, MAX_Y);
P.Result := i;
X := P.Value[0];
Y := P.Value[1];

Das Ergebnis dürfte Binär die kleinste Darstellung ergeben.

Delphi-Quellcode:

uses
  SysConst, RTLConsts, SysUtils;

const
  MinInt = Low(Integer);

type
  TIntegerPack = Record
  Private
    FList:  Array of Record
              Min, Max: Integer;
              Value:    Integer;
            End;
    FResult:  UInt64;
    FResSize: UInt64;
    Function  GetMin   (Index:    Integer): Integer;
    Function  GetMax   (Index:    Integer): Integer;
    Function  GetVal   (Index:    Integer): Integer;
    Procedure SetVal   (Index, X: Integer);
    Procedure SetResult(       X: UInt64);
    Function  GetSize  (Bits:     Integer): Integer;
  Public
    Function Add(Min, Max: Integer; Value: Integer = MinInt): Integer;
    Property Min  [Index: Integer]: Integer Read GetMin;
    Property Max  [Index: Integer]: Integer Read GetMax;
    Property Value[Index: Integer]: Integer Read GetVal Write SetVal;

    Property Result:  UInt64          Read FResult Write SetResult;
    Property ResSize: UInt64          Read FResSize;
    Property Bytes:   Integer Index 8 Read GetSize;
    Property Bits:    Integer Index 1 Read GetSize;

    Procedure Clear;
  End;

Function TIntegerPack.GetMin(Index: Integer): Integer;
  Begin
    If Cardinal(Index) >= Length(FList) Then
      Raise Exception.CreateResFmt(@SListIndexError, [Index]);
    Result := FList[Index].Min;
  End;

Function TIntegerPack.GetMax(Index: Integer): Integer;
  Begin
    If Cardinal(Index) >= Length(FList) Then
      Raise Exception.CreateResFmt(@SListIndexError, [Index]);
    Result := FList[Index].Max;
  End;

Function TIntegerPack.GetVal(Index: Integer): Integer;
  Begin
    If Cardinal(Index) >= Length(FList) Then
      Raise Exception.CreateResFmt(@SListIndexError, [Index]);
    Result := FList[Index].Value;
  End;

Procedure TIntegerPack.SetVal(Index, X: Integer);
  Begin
    If Cardinal(Index) >= Length(FList) Then
      Raise Exception.CreateResFmt(@SListIndexError, [Index]);
    If (X < FList[Index].Min) or (X > FList[Index].Max) Then
      Raise Exception.CreateRes(@SArgumentOutOfRange);
    FList[Index].Value := X;

    FResult := 0;
    For Index := High(FList) downto 0 do
      With FList[Index] do
        FResult := FResult * Cardinal(Max - Min + 1) + Cardinal(Value - Min);
  End;

Procedure TIntegerPack.SetResult(X: UInt64);
  Var Index: Integer;

  Begin
    For Index := 0 to High(FList) do
      With FList[Index] do Begin
        Value := X mod Cardinal(Max - Min + 1) + Min;
        X     := X div Cardinal(Max - Min + 1);
      End;
    //If X <> 0 Then Raise ...;
    FResult := 0;
    For Index := High(FList) downto 0 do
      With FList[Index] do
        FResult := FResult * Cardinal(Max - Min + 1) + Cardinal(Value - Min);
  End;

Function TIntegerPack.GetSize(Bits: Integer): Integer;
  Var X: UInt64;

  Begin
    Result := 0;
    X := FResSize;
    While X <> 0 do Begin
      X := X shr Bits;
      Inc(Result);
    End;
  End;

Function TIntegerPack.Add(Min, Max: Integer; Value: Integer = MinInt): Integer;
  Var Index: Integer;
    X, T:   Int64;

  Begin
    Result := Length(FList);
    SetLength(FList, Result + 1);
    Try
      FList[Result].Min := Min;
      FList[Result].Max := Max;

      X := 1;
      For Index := High(FList) downto 0 do
        With FList[Index] do Begin
          T := X;
          X := X * Cardinal(Max - Min + 1);
          If X div Cardinal(Max - Min + 1) <> T Then
            Raise EIntOverflow.CreateRes(@SIntOverflow);
        End;
      FResSize := X;
    Except
      SetLength(FList, High(FList));
      Raise;
    End;
    If Value = MinInt Then Value := Min;
    SetVal(Result, Value);
  End;

Procedure TIntegerPack.Clear;
  Begin
    FList    := nil;
    FResult  := 0;
    FResSize := 0;
  End;

und noch'n Beispiel:

Delphi-Quellcode:

Uses Dialogs;

Var P: TIntegerPack;

Begin
  P.Add(1, 13);
  P.Add(0, 5);
  P.Add(-2, 3);
  P.Value[0] := 7;
  P.Value[1] := 3;
  P.Value[2] := 1;
  ShowMessage(Format('%d Bytes  >  %d Bits  >  $%.*x',
    [P.Bytes, P.Bits, P.Bytes * 2, P.Result]));

  P.Add(1, 13);
  P.Add(0, 5);
  P.Add(-2, 3);
  P.Result := $0117;
  ShowMessage(Format('%d  >  %d %d %d',
    [P.Result, P.Value[0], P.Value[1], P.Value[2]]));