Lab.6.2

procedure InitializeChessDesk(var Arr: TArrDesk);
var
    I, J: Integer;
begin
    for I := 0 to High(Arr) do
        for J := 0 to High(Arr) do
            Arr[I][J] := 0;
end;

function MakeWay(Desk: TArrDesk; var Way: TWay; CurrX, CurrY: Integer): TArrDesk;
var
    I, J, K: Integer;
    CurrNX, CurrNY, CurrCount: Integer;
    PossX, PossY, PossCount: Integer;
begin
    PossX := 0;
    PossY := 0;
    CurrCount := MAX_POSSIBLE_STEPS;
    PossCount := MAX_POSSIBLE_STEPS;
    Desk[CurrX][CurrY] := 1;
    Way[1][0] := CurrX;
    Way[1][1] := CurrY;
    for I := 2 to (DIMENSION * DIMENSION) do
    begin
        for J := 0 to (MAX_POSSIBLE_STEPS - 1) do
        begin
            if (CurrX + Possible_moves[J][0] >= MIN_POSSIBLE_STEPS)
            and (CurrX + Possible_moves[J][0] < MAX_POSSIBLE_STEPS) and
            (CurrY + Possible_moves[J][1] >= MIN_POSSIBLE_STEPS)
            and (CurrY + Possible_moves[J][1] < MAX_POSSIBLE_STEPS)
            and (Desk[CurrX + Possible_moves[J][0]][CurrY + Possible_moves[J][1]] = 0) then
            begin
                CurrCount := 0;
                CurrNX := CurrX + Possible_moves[J][0];
                CurrNY := CurrY + Possible_moves[J][1];
                for K := 0 to (MAX_POSSIBLE_STEPS - 1) do
                begin
                    if (CurrNX + Possible_moves[K][0] >= MIN_POSSIBLE_STEPS) and (CurrNX + Possible_moves[K][0] < MAX_POSSIBLE_STEPS) and
                    (CurrNY + Possible_moves[K][1] >= MIN_POSSIBLE_STEPS) and (CurrNY + Possible_moves[K][1] < MAX_POSSIBLE_STEPS)
                    and (Desk[CurrNX + Possible_moves[K][0]][CurrNY + Possible_moves[K][1]] = 0) then
                    begin
                        Inc(CurrCount);
                    end;
                end;
            end;
            if PossCount > CurrCount then
            begin
                PossX := CurrNX;
                PossY := CurrNY;
                PossCount := CurrCount;
            end;
        end;
        CurrX := PossX;
        CurrY := PossY;
        CurrNX := 0;
        CurrNY := 0;
        CurrCount := MAX_POSSIBLE_STEPS;
        PossCount := MAX_POSSIBLE_STEPS;
        Desk[CurrX][CurrY] := I;
        Way[I][0] := CurrX;
        Way[I][1] := CurrY;
    end;
    MakeWay := Desk;
end;

procedure DrawCellDesignation(var Desk: TImage);
var
    I: Integer;
    J: Char;
begin
    J := #97;               //'a'..'h' = #97..#104
    with Desk.Canvas do
    begin
        MoveTo(0, 0);
        Pen.Color := clBlack;
        Brush.Color := clWhite;
        for I := 0 to (DIMENSION - 1) do
        begin
            Rectangle((I * X_CHANGE), 0, ((I + 1) * X_CHANGE), Y_CHANGE);
            TextOut((I * X_CHANGE + TEXT_MARGIN_X_HOR), TEXT_MARGIN_Y_HOR, J);
            Rectangle((DIMENSION * X_CHANGE), (Y_CHANGE + X_CHANGE * I), (DIMENSION * X_CHANGE + Y_CHANGE), (Y_CHANGE + X_CHANGE * (I + 1)));
            TextOut((DIMENSION * X_CHANGE + TEXT_MARGIN_X_VER), (Y_CHANGE + X_CHANGE * I + TEXT_MARGIN_X_HOR), IntToStr(I + 1));
            Inc(J);
        end;
    end;
end;

procedure DrawCellLine(FirstColor: TColor; var Desk: TImage; CurrY: Integer);
var
    I: Integer;
    CurrColor: TColor;
begin
    CurrColor := FirstColor;
    with Desk.Canvas do
    begin
        for I := 0 to (DIMENSION - 1) do
        begin
            Brush.Color := CurrColor;
            Rectangle((I * CELL_CHANGE), CurrY, ((I + 1) * CELL_CHANGE), (CurrY + CELL_CHANGE));
            ChangeColor(CurrColor);
        end;
    end;
end;

procedure DrawWay(Desk: TImage; I, X, Y: Integer);
var
    Numb: String;
begin
    Numb := IntToStr(I);
    Desk.Canvas.TextOut((CELL_CHANGE * X + NUMBERS_MARGIN_HOR), (Y_CHANGE + Y * CELL_CHANGE + NUMBERS_MARGIN_VER), Numb);
end;

procedure DrawChessDesk(ChessDesk: TImage);
var
    I: Integer;
begin
    with ChessDesk.Canvas do
    begin
        Pen.Color := clBlack;
        Brush.Color := clWhite;
        Font.Color := clBlack;
        Font.Size := 9;
        Font.Style := [];
        DrawCellDesignation(ChessDesk);
        for I := 0 to DIMENSION - 1 do
        begin
            if I mod 2 = 1 then
                DrawCellLine(clBlack, ChessDesk, (Y_CHANGE + I * (CELL_CHANGE)))
            else
                DrawCellLine(clWhite, ChessDesk, (Y_CHANGE + I * (CELL_CHANGE)));
        end;
    end;
end;

procedure TForm_6_2.ButtonFindMovesClick(Sender: TObject);
var
    IsCorrect: Boolean;
    Error: String;
    StartX, StartY: Integer;
begin
    ButtonFindMoves.Enabled := false;
    IsCorrect := true;
    Error := '';
    try
        StartX := Ord(EditStartLetter.Text[1]) - CHARACTER_CODE_MIN;
        if (StartX < MIN_NUMBER) or (StartX > (DIMENSION - 1)) then
        begin
            IsCorrect := false;
            Error := 'Введена недопустимая буква стартовой позиции. ';
        end;
        StartY := StrToInt(EditStartDigit.Text) - 1;
        if (StartY < MIN_NUMBER) or (StartY > (DIMENSION - 1)) then
        begin
            IsCorrect := false;
            Error := Error + 'Введена недопустимая цифра стартовой позиции. ';
        end;
    except
        IsCorrect := false;
        Error := 'Найдено некорректно введённое значение! ' + Error;
    end;
    if (IsCorrect) then
    begin
        Counter := 1;
        DrawChessDesk(ChessDesk);
        InitializeChessDesk(Answer);
        Answer := MakeWay(Answer, Way, StartX, StartY);
        ChessDesk.Canvas.Font.Color := clHotLight;
        ChessDesk.Canvas.Brush.Style := bsClear;
        ChessDesk.Canvas.Font.Size := 10;
        ChessDesk.Canvas.Font.Style := [fsBold];
        Timer.Enabled := true;
        ButtonSaveFile.Enabled := true;
    end
    else
    begin
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' +  Error;
        UnitError.FormError.ShowModal;
        UnitError.FormError.LabelError.Caption := '';
    end;
end;