| Description | ||
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The Points array of points defines a regular or irregular polygon shape. FillPolygon fills in the shape with the specified Brush.
Normally a polygon is deemed to be a shape with angles greater than 90 degrees (obtuse angles). However, a Microsoft polygon can have acute angles, and can overlap itself. The FillMode optional parameter allows you to define how the fill process handles such an overlapping :
Winding counts the number of lines crossed when radiating out from a point to determine if it is inside the shape. Alternate looks at curve intersections, and the directions each is drawn. | ||
| Microsoft MSDN Links | ||
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System.Drawing System.Drawing.Graphics |
| Drawing a red polygon and a yellow/blue hatched polygon | ||
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// Full Unit code. // ------------------------------------------------------------- // Create a new WinForm application, double click the form to // create an OnLoad event, and then replace the WinForm unit // with this text. unit WinForm; interface uses System.Drawing, System.Collections, System.ComponentModel, System.Windows.Forms, System.Data; type TWinForm = class(System.Windows.Forms.Form) \{REGION 'Designer Managed Code'\} // Note that REGION and ENREGION should be prefixed by a dollar sign strict private /// /// Required designer variable. /// Components: System.ComponentModel.Container; /// /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// procedure InitializeComponent; procedure TWinForm_Load(sender: System.Object; e: System.EventArgs); {ENDREGION} strict protected /// /// Clean up any resources being used. /// procedure Dispose(Disposing: Boolean); override; private { Private Declarations } public constructor Create; end; [assembly: RuntimeRequiredAttribute(TypeOf(TWinForm))] implementation \{REGION 'Windows Form Designer generated code'\} /// /// Required method for Designer support -- do not modify /// the contents of this method with the code editor. /// procedure TWinForm.InitializeComponent; begin // // TWinForm // Self.AutoScaleBaseSize := System.Drawing.Size.Create(5, 13); Self.ClientSize := System.Drawing.Size.Create(292, 266); Self.Name := 'TWinForm'; Self.Text := 'WinForm'; Include(Self.Load, Self.TWinForm_Load); end; {ENDREGION} procedure TWinForm.Dispose(Disposing: Boolean); begin if Disposing then begin if Components <> nil then Components.Dispose(); end; inherited Dispose(Disposing); end; constructor TWinForm.Create; begin inherited Create; // // Required for Windows Form Designer support // InitializeComponent; // // TODO: Add any constructor code after InitializeComponent call // end; procedure TWinForm.TWinForm_Load(sender: System.Object; e: System.EventArgs); procedure TWinForm.TWinForm_Paint(sender: System.Object; e: System.Windows.Forms.PaintEventArgs); var solidBrush : System.Drawing.SolidBrush; hatchBrush : System.Drawing.Drawing2D.HatchBrush; points : Array[1..6] of System.Drawing.Point; begin // Create the brushes solidBrush := System.Drawing.SolidBrush.Create(Color.Red); hatchBrush := System.Drawing.Drawing2D.HatchBrush.Create(HatchStyle.Vertical, Color.Blue, Color.Yellow); // Build the points array to form an elongated 6 sided polygon // Note that FillPolygon adds the final link line points[1] := Point.Create(10, 5); points[2] := Point.Create(20, 5); points[3] := Point.Create(25, 10); points[4] := Point.Create(20, 15); points[5] := Point.Create(10, 15); points[6] := Point.Create( 5, 10); // Draw this polygon using a solid red brush e.Graphics.FillPolygon(solidBrush, points); // Draw another polygon using a hatch brush points[1] := Point.Create(40, 5); points[2] := Point.Create(50, 5); points[3] := Point.Create(55, 10); points[4] := Point.Create(50, 15); points[5] := Point.Create(40, 15); points[6] := Point.Create(35, 10); e.Graphics.FillPolygon(hatchBrush, points); end; end. | ||
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| Illustrating the two types of FillMode | ||
| procedure TWinForm.TWinForm_Paint(sender: System.Object;
e: System.Windows.Forms.PaintEventArgs); var solidBrush : System.Drawing.SolidBrush; points : Array[1..10] of System.Drawing.Point; begin // Create the brush solidBrush := System.Drawing.SolidBrush.Create(Color.Red); // Build the points array to form an overlapping polygon // Note that FillPolygon adds the final link line points[1] := Point.Create( 5, 6); points[2] := Point.Create(20, 6); points[3] := Point.Create(20, 14); points[4] := Point.Create(10, 14); points[5] := Point.Create(10, 10); points[6] := Point.Create(25, 10); points[7] := Point.Create(25, 2); points[8] := Point.Create(15, 2); points[9] := Point.Create(15, 18); points[10] := Point.Create( 5, 18); // Draw this polygon using a solid red brush and winding filling e.Graphics.FillPolygon(solidBrush, points, FillMode.Winding); points[1] := Point.Create(35, 6); points[2] := Point.Create(50, 6); points[3] := Point.Create(50, 14); points[4] := Point.Create(40, 14); points[5] := Point.Create(40, 10); points[6] := Point.Create(55, 10); points[7] := Point.Create(55, 2); points[8] := Point.Create(45, 2); points[9] := Point.Create(45, 18); points[10] := Point.Create(35, 18); // Draw this polygon using a solid blue brush and alternate filling solidBrush.Color := Color.Blue; e.Graphics.FillPolygon(solidBrush, points, FillMode.Alternate); end; | ||
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