Graphics::DrawCurve(constPen*,constPointF*,INT,INT,INT,REAL) method (gdiplusgraphics.h)

The Graphics::DrawCurve method draws a cardinal spline.

Syntax

Status DrawCurve(
  [in] const Pen    *pen,
  [in] const PointF *points,
  [in] INT          count,
  [in] INT          offset,
  [in] INT          numberOfSegments,
  [in] REAL         tension
);

Parameters

[in] pen

Type: const Pen*

Pointer to a pen that is used to draw the cardinal spline.

[in] points

Type: const PointF*

Pointer to an array of PointF objects that specify the coordinates that the cardinal spline passes through.

[in] count

Type: INT

Integer that specifies the number of elements in the points array.

[in] offset

Type: INT

Integer that specifies the element in the points array that specifies the point at which the cardinal spline begins.

[in] numberOfSegments

Type: INT

Integer that specifies the number of segments in the cardinal spline.

[in] tension

Type: REAL

Real number that specifies how tightly the curve bends through the coordinates of the cardinal spline.

Return value

Type: Status

If the method succeeds, it returns Ok, which is an element of the Status enumeration.

If the method fails, it returns one of the other elements of the Status enumeration.

Remarks

A segment is defined as a curve that connects two consecutive points in the cardinal spline. The ending point of each segment is the starting point for the next. The numberOfSegments parameter must not be greater than the count parameter minus the offset parameter plus one.

Examples

The following example draws a cardinal spline.

VOID Example_DrawCurve5(HDC hdc)
{
   Graphics graphics(hdc);

   // Define a Pen object and an array of PointF objects.
   Pen greenPen(Color::Green, 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 curvePoints[4] = {
   point1,
   point2,
   point3,
   point4};

   PointF* pcurvePoints = curvePoints;

   // Specify offset, number of segments to draw, and tension.
   int offset = 1;
   int segments = 2;
   REAL tension = 1.0f;

   // Draw the curve.
   graphics.DrawCurve(&greenPen, curvePoints, 4, offset, segments, tension);

   //Draw the points in the curve.
   SolidBrush redBrush(Color::Red);
   graphics.FillEllipse(&redBrush, Rect(95, 95, 10, 10));
   graphics.FillEllipse(&redBrush, Rect(195, 45, 10, 10));
   graphics.FillEllipse(&redBrush, Rect(395, 5, 10, 10));
   graphics.FillEllipse(&redBrush, Rect(495, 95, 10, 10));
}

Requirements

See also

Cardinal Splines

DrawClosedCurve Methods

Drawing Cardinal Splines

Graphics

Pen

Point