GdiPlus[36]: IGPGraphicsPath (三) 路径中的数据

IGPGraphicsPath.PointCount;   // 点总数

IGPGraphicsPath.PathPoints;   // 点数组, 浮点型

IGPGraphicsPath.PathPointsI;  // 点数组, 整型

IGPGraphicsPath.PathTypes;    // 点类型数组

IGPGraphicsPath.PathData;     // 点与点类型数据, IGPPathData 类型



IGPGraphicsPath.GetLastPoint; // 尾点

IGPGraphicsPath.Reverse;      // 反转点顺序



IGPGraphicsPath.GetBounds();  // 获取包围矩形
 
   




{ 关于点类型(它是个 Byte 值) }

0   // 指示此点是图形的起始点

1   // 指示此点是线段的两个终结点之一

3   // 指示此点是立方贝塞尔样条的终结点或控制点

$7  // 用于 3 位掩码运算的, 应该不会实际存在

$20 // 指定此点是一个 Marker(标记)

$80 // 指定此点是闭合子路径（图形）中的最后一点



//实际读出的值如果不是这样, 应该是该点有双重身份.


 
   

PathPoints、PathTypes、PathData 测试图:

---

PathPoints、PathTypes、PathData 测试代码:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Path: IGPGraphicsPath;

  Brush,BrushPt,BrushText: IGPSolidBrush;

  Pt: TGPPointF;

  PtType: Byte;

  i: Integer;

begin

  Graphics := TGPGraphics.Create(Handle);

  Brush := TGPSolidBrush.Create($FFC0C0C0);

  BrushPt := TGPSolidBrush.Create($80FF0000);

  BrushText := TGPSolidBrush.Create($FF000000);



  Path := TGPGraphicsPath.Create;

  Path.AddString('A', TGPFontFamily.Create('Arial Black'), [], 200, TGPPoint.Create(0,0), nil);

  Path.AddEllipse(210, 76, 100, 144);



  Graphics.FillPath(Brush, Path);

  for i := 0 to Path.PointCount - 1 do

  begin

    Pt := Path.PathPoints[i];

    PtType := Path.PathTypes[i];

    //上两行也可以写作:

    //Pt := Path.PathData.Points[i];

    //PtType := Path.PathData.Types[i];



    Graphics.FillRectangle(BrushPt, Pt.X-3, Pt.Y-3, 6, 6);

    Graphics.DrawString(Format('%x', [PtType]), TGPFont.Create(Canvas.Handle), Pt, BrushText);

  end;

end;


 
   

GetLastPoint、Reverse、PathPointsI 测试代码:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Path: IGPGraphicsPath;

  PtStart: TGPPoint;

  PtEnd: TGPPointF;

begin

  Path := TGPGraphicsPath.Create;

  Path.AddRectangle(TGPRect.Create(1, 2, 3, 4));



  PtStart := Path.PathPointsI[0];

  PtEnd := Path.GetLastPoint;

  ShowMessageFmt('%d;%d, %g;%g', [PtStart.X, PtStart.Y, PtEnd.X, PtEnd.Y]);

  { (1;2), (1;6) }



  Path.Reverse;

  PtStart := Path.PathPointsI[0];

  PtEnd := Path.GetLastPoint;

  ShowMessageFmt('%d;%d, %g;%g', [PtStart.X, PtStart.Y, PtEnd.X, PtEnd.Y]);

  { (1;6), (1;2) }

end;


 
   

GetBounds 测试图:

---

GetBounds 测试代码:

---

uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Path: IGPGraphicsPath;

  Pen: IGPPen;

  Rect: TGPRect;

begin

  Graphics := TGPGraphics.Create(Handle);

  Pen := TGPPen.Create($FFFF0000, 2);

  Path := TGPGraphicsPath.Create;

  Path.AddLine(20, 20, 150, 100);



  Graphics.DrawPath(Pen, Path);



  Pen.Width := 1;

  Pen.Color := $FFC0C0C0;

  Path.GetBounds(Rect);

  Graphics.DrawRectangle(Pen, Rect);

end;