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

The Graphics::DrawCurve method draws a cardinal spline.

Syntax

Status DrawCurve(
  [in] const Pen   *pen,
  [in] const Point *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 Point*

Pointer to an array of Point 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_DrawCurve2(HDC hdc)
{
   Graphics graphics(hdc);

   // Define a Pen object and an array of Point objects.
   Pen greenPen(Color::Green, 3);
   Point point1(100, 100);
   Point point2(200, 50);
   Point point3(400, 10);
   Point point4(500, 100);

   Point curvePoints[4] = {
   point1,
   point2,
   point3,
   point4};

   Point* pcurvePoints = curvePoints;

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

   // 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