GdiPlus[37]: IGPGraphicsPath (四) 路径变换

IGPGraphicsPath.Flatten();   //把路径中的曲线转换为近似直线段(路径中只有 Bezier 线和直线).

IGPGraphicsPath.Outline();   //同 Flatten();

IGPGraphicsPath.Warp();      //四边形或平行四边形扭曲. 

IGPGraphicsPath.Widen();     //把轮廓转换为范围.

IGPGraphicsPath.Transform(); //矩阵变换; 其实上面几个方法都包含矩阵变换的参数.


 
   

Flatten 测试图:

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Flatten 测试代码:

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uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Pen: IGPPen;

  Brush: IGPBrush;

  Path, PathClone: IGPGraphicsPath;

  Rect: TGPRect;

  Pt: TGPPoint;

  Matrix: IGPMatrix;

begin

  Graphics := TGPGraphics.Create(Canvas.Handle);

  Pen := TGPPen.Create($FFFF0000);

  Brush := TGPSolidBrush.Create($800000FF);

  Path := TGPGraphicsPath.Create;

  Rect.Initialize(20, 20, 200, 75);

  Path.AddEllipse(Rect);



  PathClone := Path.Clone;

  Graphics.DrawPath(Pen, PathClone);

  for Pt in PathClone.PathPointsI do Graphics.FillRectangle(Brush, Pt.X-2, Pt.Y-2, 4, 4);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);



  PathClone := Path.Clone;

  PathClone.Flatten(); //其参数 2 默认是 0.25

  Graphics.DrawPath(Pen, PathClone);

  for Pt in PathClone.PathPointsI do Graphics.FillRectangle(Brush, Pt.X-2, Pt.Y-2, 4, 4);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);



  PathClone := Path.Clone;

  PathClone.Flatten(nil, 10);

  Graphics.DrawPath(Pen, PathClone);

  for Pt in PathClone.PathPointsI do Graphics.FillRectangle(Brush, Pt.X-2, Pt.Y-2, 4, 4);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);



  PathClone := Path.Clone;

  PathClone.Flatten(nil, 25);

  Graphics.DrawPath(Pen, PathClone);

  for Pt in PathClone.PathPointsI do Graphics.FillRectangle(Brush, Pt.X-2, Pt.Y-2, 4, 4);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);



  PathClone := Path.Clone;

  PathClone.Flatten(nil, 50);

  Graphics.DrawPath(Pen, PathClone);

  for Pt in PathClone.PathPointsI do Graphics.FillRectangle(Brush, Pt.X-2, Pt.Y-2, 4, 4);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);



  PathClone := Path.Clone;

  Matrix := TGPMatrix.Create;

  Matrix.Scale(1, 0.5);

  Matrix.Translate(0, 20);

  PathClone.Flatten(Matrix, 25);

  Graphics.DrawPath(Pen, PathClone);

  for Pt in PathClone.PathPointsI do Graphics.FillRectangle(Brush, Pt.X-2, Pt.Y-2, 4, 4);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);

end;


 
   

Warp 测试图:

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Warp 测试代码:

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uses GdiPlus;



const

  { 数组有三个元素时, 0: 左上; 1: 右上; 2: 左下; 3: 自动调整为平行四边形 }

  pts3: array[0..2] of TGPPointF = ((X:20; Y:20),(X:250; Y:0),(X:20; Y:120));



  { 数组有四个元素时, 0: 左上; 1: 右上; 2: 左下; 3: 右下 }

  pts4: array[0..3] of TGPPointF = ((X:20; Y:20),(X:220; Y:10),(X:20; Y:120),(X:270; Y:190));



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Brush: IGPHatchBrush;

  Path,PathClone: IGPGraphicsPath;

  Rect: TGPRectF;

  FontFamily: IGPFontFamily;

  StringFormat: IGPStringFormat;

  Pt: TGPPointF;

begin

  Graphics := TGPGraphics.Create(Canvas.Handle);

  Brush := TGPHatchBrush.Create(HatchStyleShingle, $FF808080, $FF483D8B);



  Rect.Initialize(20, 20, 250, 120);

  FontFamily := TGPFontFamily.Create('Arial Black');

  StringFormat := TGPStringFormat.Create;

  StringFormat.Alignment := StringAlignmentCenter;

  StringFormat.LineAlignment := StringAlignmentCenter;



  Path := TGPGraphicsPath.Create;

  Path.AddRectangle(Rect);

  Path.AddString('Delphi', FontFamily, [], 56, Rect, StringFormat);



  PathClone := Path.Clone;

  Graphics.FillPath(Brush, PathClone);

  Graphics.TranslateTransform(0, Rect.Y*2 + Rect.Height);



  //PathClone := Path.Clone;

  PathClone.Warp(pts3, Rect);

  Graphics.FillPath(Brush, PathClone);

  Graphics.TranslateTransform(0, Rect.Y*2 + Rect.Height);



  PathClone := Path.Clone;

  PathClone.Warp(pts4, Rect);

  Graphics.FillPath(Brush, PathClone);

  Graphics.TranslateTransform(0, Rect.Y*2 + Rect.Height);

end;


 
   

Widen 测试图:

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Widen 测试代码:

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uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Pen: IGPPen;

  Brush: IGPHatchBrush;

  Path, PathClone: IGPGraphicsPath;

  Rect: TGPRect;

begin

  Graphics := TGPGraphics.Create(Canvas.Handle);

  Pen := TGPPen.Create($AAFF0000, 20);

  Brush := TGPHatchBrush.Create(HatchStyleShingle, $FFC0C0C0, $FF888888);

  Path := TGPGraphicsPath.Create;

  Rect.Initialize(20, 20, 200, 75);

  Path.AddEllipse(Rect);



  PathClone := Path.Clone;

  Graphics.FillPath(Brush, PathClone);

  Graphics.DrawPath(Pen, PathClone);

  Graphics.TranslateTransform(0, Rect.Y*2 + Rect.Height);



  PathClone := Path.Clone;

  PathClone.Widen(Pen);

  Graphics.FillPath(Brush, PathClone);

  Pen.Width := 1;

  Graphics.DrawPath(Pen, PathClone);

  Graphics.TranslateTransform(0, Rect.Y + Rect.Height);

end;


 
   

Translate 测试图:

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Translate 测试代码:

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uses GdiPlus;



procedure TForm1.FormPaint(Sender: TObject);

var

  Graphics: IGPGraphics;

  Brush: IGPHatchBrush;

  Path,PathClone: IGPGraphicsPath;

  FontFamily: IGPFontFamily;

  Pt: TGPPointF;

  Matrix: IGPMatrix; 

begin

  Graphics := TGPGraphics.Create(Canvas.Handle);

  Brush := TGPHatchBrush.Create(HatchStyleZigZag, $FFC0C0C0, $FFFF0000);



  FontFamily := TGPFontFamily.Create('Arial Black');

  Pt.Initialize(0, 0);

  Path := TGPGraphicsPath.Create;

  Path.AddString('Delphi', FontFamily, [], 32, Pt, nil);



  Graphics.FillPath(Brush, Path);



  PathClone := Path.Clone;

  Matrix := TGPMatrix.Create;

  Matrix.Scale(2, 2);

  Matrix.Rotate(-30);

  Matrix.Translate(-35, 45);

  PathClone.Transform(Matrix);

  Graphics.FillPath(Brush, PathClone);

  

  PathClone := Path.Clone;

  Matrix.Reset;

  Matrix.Scale(2.5, 6);

  Matrix.Translate(0, 18);

  PathClone.Transform(Matrix);

  Graphics.FillPath(Brush, PathClone);

end;