| 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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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; | ||
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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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