WinAPI: ExtCreateRegion - 区域变换

相似函数: SetWorldTransform

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本例效果图:

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代码文件:

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unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ExtCtrls;



type

  TForm1 = class(TForm)

    RadioGroup1: TRadioGroup;

    procedure FormCreate(Sender: TObject);

    procedure FormPaint(Sender: TObject);

    procedure RadioGroup1Click(Sender: TObject);

    procedure FormDestroy(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  cvs: TCanvas;

  Rgn: HRGN;



procedure TForm1.FormCreate(Sender: TObject);

begin

  cvs := TCanvas.Create;

  cvs.Handle := GetDC(Handle);



  RadioGroup1.Items.CommaText :=

  '原始,横向移动,纵向移动,横向比例,纵向比例,放大,缩小,水平镜像,垂直镜像,横向斜切,纵向斜切,旋转';

  RadioGroup1.ItemIndex := 0;

end;



procedure TForm1.FormDestroy(Sender: TObject);

begin

  DeleteObject(Rgn);

  cvs.Free;

end;



procedure TForm1.FormPaint(Sender: TObject);

begin

  {绘制}

  cvs.Brush.Color := clSilver;

  cvs.Brush.Style := bsDiagCross;

  FillRgn(cvs.Handle, Rgn, cvs.Brush.Handle);

  cvs.Brush.Color := clRed;

  cvs.Brush.Style := bsSolid;

  FrameRgn(cvs.Handle, Rgn, cvs.Brush.Handle, 2, 2);

end;





procedure TForm1.RadioGroup1Click(Sender: TObject);

var

  RgnDataSize: Integer; {区域数据缓冲区的大小}

  RgnData: PRgnData;    {区域数据指针}

  TXF: TXForm;          {坐标转换的矩阵结构}

begin

  cvs.Font.Size := 120;

  cvs.Font.Style := [fsBold];

  SetBkMode(cvs.Handle, TRANSPARENT);



  {建立路径}

  BeginPath(cvs.Handle);

  cvs.TextOut(100, 0, 'F');

  EndPath(cvs.Handle);



  {将路径转换为区域}

  Rgn := PathToRegion(cvs.Handle);



  {获取区域数据}

  RgnDataSize := GetRegionData(Rgn, 0, nil);

  GetMem(RgnData, RgnDataSize);

  GetRegionData(Rgn, RgnDataSize, RgnData);



  case RadioGroup1.ItemIndex of

    0: begin {原始效果, 无变换}

      TXF.eM11 := 1;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    1: begin {右移 100}

      TXF.eM11 := 1;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1;

      TXF.eDx := 100;

      TXF.eDy := 0;

    end;

    2: begin {上移 40}

      TXF.eM11 := 1;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1;

      TXF.eDx := 0;

      TXF.eDy := -40;

    end;

    3: begin {横向放大 1.5}

      TXF.eM11 := 1.5;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    4: begin {纵向放大 1.5}

      TXF.eM11 := 1;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1.5;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    5: begin {整体放大 1.5 倍}

      TXF.eM11 := 1.5;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1.5;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    6: begin {整体缩小一半}

      TXF.eM11 := 0.5;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 0.5;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    7: begin {水平镜像}

      TXF.eM11 := -1;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := 1;

      TXF.eDx := 200; {需要右移一些才能看到}

      TXF.eDy := 0;

    end;

    8: begin {垂直镜像}

      TXF.eM11 := 1;

      TXF.eM12 := 0;

      TXF.eM21 := 0;

      TXF.eM22 := -1;

      TXF.eDx := 0;

      TXF.eDy := 200; {需要下移一些才能看到}

    end;

    9: begin {横向斜切}

      TXF.eM11 := 1;

      TXF.eM12 := 0.75;

      TXF.eM21 := 0;

      TXF.eM22 := 1;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    10: begin {纵向斜切}

      TXF.eM11 := 1;

      TXF.eM12 := 0;

      TXF.eM21 := 0.75;

      TXF.eM22 := 1;

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

    11: begin {旋转 30 度}

      TXF.eM11 := Cos(30*PI/180);

      TXF.eM12 := Sin(30*PI/180);

      TXF.eM21 := -Sin(30*PI/180);

      TXF.eM22 := Cos(30*PI/180);

      TXF.eDx := 0;

      TXF.eDy := 0;

    end;

  end;



  {执行变换并重绘}

  Rgn := ExtCreateRegion(@TXF, RgnDataSize, RgnData^);

  Repaint;



  FreeMem(RgnData);

end;



end.


 
   

窗体文件:

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object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 259

  ClientWidth = 433

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  Position = poDesktopCenter

  OnCreate = FormCreate

  OnDestroy = FormDestroy

  OnPaint = FormPaint

  PixelsPerInch = 96

  TextHeight = 13

  object RadioGroup1: TRadioGroup

    Left = 320

    Top = 8

    Width = 103

    Height = 243

    Caption = 'RadioGroup1'

    TabOrder = 0

    OnClick = RadioGroup1Click

  end

end