Direct2D (30) : 判断几何对象的关系 - ID2D1Geometry.CompareWithGeometry()

{相关常量}

//D2D1_GEOMETRY_RELATION = type Integer;

D2D1_GEOMETRY_RELATION_UNKNOWN      = 0;  //未知

D2D1_GEOMETRY_RELATION_DISJOINT     = 1;  //不相交

D2D1_GEOMETRY_RELATION_IS_CONTAINED = 2;  //属于

D2D1_GEOMETRY_RELATION_CONTAINS     = 3;  //包含

D2D1_GEOMETRY_RELATION_OVERLAP      = 4;  //重叠

---

测试代码：

---

uses Direct2D, D2D1;



procedure TForm1.FormPaint(Sender: TObject);

const

  arr1: array[0..3] of string = ('红色', '黄色', '绿色', '蓝色');

  arr2: array[1..4] of string = ('不相交于', '属于', '包含', '相交于');

  arrColor: array[0..3] of TColor = (clRed, clYellow, clGreen, clBlue);

var

  cvs: TDirect2DCanvas;

  iEllipseGeometry: ID2D1EllipseGeometry;

  iRectangleGeometrys: array[0..3] of ID2D1RectangleGeometry;

  i,h: Integer;

  x: D2D1_GEOMETRY_RELATION;

  strArr: array[0..3] of string;

begin

  D2DFactory.CreateEllipseGeometry(D2D1Ellipse(D2D1PointF(150, 150), 50, 50), iEllipseGeometry);

  D2DFactory.CreateRectangleGeometry(D2D1RectF(90, 90, 210, 210), iRectangleGeometrys[0]);

  D2DFactory.CreateRectangleGeometry(D2D1RectF(130, 130, 170, 170), iRectangleGeometrys[1]);

  D2DFactory.CreateRectangleGeometry(D2D1RectF(70, 130, 110, 170), iRectangleGeometrys[2]);

  D2DFactory.CreateRectangleGeometry(D2D1RectF(220, 130, 260, 170), iRectangleGeometrys[3]);



  for i := 0 to 3 do

  begin

    iEllipseGeometry.CompareWithGeometry(iRectangleGeometrys[i], TD2DMatrix3x2F.Identity, 0, x);

    strArr[i] := Format('圆 "%s"'#9'%s矩形', [arr2[x], arr1[i]]);

  end;



  cvs := TDirect2DCanvas.Create(Canvas, ClientRect);

  cvs.BeginDraw;

  cvs.RenderTarget.Clear(D2D1ColorF(clWhite));



  for i := 0 to 3 do

  begin

    cvs.Brush.Color := arrColor[i];

    cvs.FillGeometry(iRectangleGeometrys[i]);

  end;



  cvs.Font.Size := 10;

  cvs.Brush.Color := clWhite;

  h := cvs.TextHeight(strArr[0]);

  for i := 0 to 3 do cvs.TextOut(8, h*i+5, strArr[i]);



  cvs.EndDraw;

  cvs.Free;

end;

---

效果图：

---