The following example draws a closed cardinal spline.
C++
VOID Example_DrawClosedCurve3(HDC hdc)
{
Graphics graphics(hdc);
// Define a Pen object and an array of PointF objects.
Pen greenPen(Color(255, 0, 0, 255), 3);
PointF point1(100.0f, 100.0f);
PointF point2(200.0f, 50.0f);
PointF point3(400.0f, 10.0f);
PointF point4(500.0f, 100.0f);
PointF point5(600.0f, 200.0f);
PointF point6(700.0f, 400.0f);
PointF point7(500.0f, 500.0f);
PointF curvePoints[7] = {
point1,
point2,
point3,
point4,
point5,
point6,
point7};
// Draw the closed curve.
graphics.DrawClosedCurve(&greenPen, curvePoints, 7);
// Draw the points in the curve.
SolidBrush redBrush(Color(255, 255, 0, 0));
graphics.FillEllipse(&redBrush, Rect(95, 95, 10, 10));
graphics.FillEllipse(&redBrush, Rect(495, 95, 10, 10));
graphics.FillEllipse(&redBrush, Rect(495, 495, 10, 10));
graphics.FillEllipse(&redBrush, Rect(195, 45, 10, 10));
graphics.FillEllipse(&redBrush, Rect(395, 5, 10, 10));
graphics.FillEllipse(&redBrush, Rect(595, 195, 10, 10));
graphics.FillEllipse(&redBrush, Rect(695, 395, 10, 10));
}
SUB GDIP_DrawClosedCurve (BYVAL hdc AS DWORD)
LOCAL hStatus AS LONG
LOCAL pGraphics AS DWORD
LOCAL pGreenPen AS DWORD
LOCAL pRedBrush AS DWORD
LOCAL point1 AS POINTF
LOCAL point2 AS POINTF
LOCAL point3 AS POINTF
LOCAL point4 AS POINTF
LOCAL point5 AS POINTF
LOCAL point6 AS POINTF
LOCAL point7 AS POINTF
DIM curvePoints(6) AS POINTF
hStatus = GdipCreateFromHDC(hdc, pGraphics)
' // Create a green Pen
hStatus = GdipCreatePen1(GDIP_ARGB(255, 0, 255, 0), 1.0!, %UnitWorld, pGreenPen)
point1.x = 100.0 : point1.y = 100.0
point2.x = 200.0 : point2.y = 50.0
point3.x = 400.0 : point3.y = 10.0
point4.x = 500.0 : point4.y = 100.0
point5.x = 600.0 : point5.y = 200.0
point6.x = 700.0 : point6.y = 400.0
point7.x = 500.0 : point7.y = 500.0
curvePoints(0) = point1
curvePoints(1) = point2
curvePoints(2) = point3
curvePoints(3) = point4
curvePoints(4) = point5
curvePoints(5) = point6
curvePoints(6) = point7
' // Draw the closed curve
hStatus = GdipDrawClosedCurve(pGraphics, pGreenPen, curvePoints(0), 7)
' // Create the brush
hStatus = GdipCreateSolidFill(GDIP_ARGB(255, 255, 0, 0), pRedBrush)
' //Draw the points in the curve
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 95, 95, 10, 10)
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 495, 95, 10, 10)
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 495, 495, 10, 10)
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 195, 45, 10, 10)
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 395, 5, 10, 10)
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 595, 195, 10, 10)
hStatus = GdipFillEllipse(pGraphics, pRedBrush, 695, 395, 10, 10)
' // Cleanup
IF pRedBrush THEN GdipDeleteBrush(pRedBrush)
IF pGreenPen THEN GdipDeletePen(pGreenPen)
IF pGraphics THEN GdipDeleteGraphics(pGraphics)
END SUB
(http://www.jose.it-berater.org/captures/GdipDrawClosedCurve.png)