WinAPI: ExtCreateRegion - 区域变换

转载：http://www.cnblogs.com/del/archive/2008/06/03/1212534.html

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

TXForm 结构定义在 Windows 单元的 12205 - 12213 行(Delphi 2007).