描述

 

绘制闭基数样条.

 

C++ Syntax

 

 

 

 

 

FreeBASIC 语法

 

 

 

 

 

参数

 

pPen

 

[in]指针的那一支钢笔是用来绘制闭合的基数样条曲线.

 

pts

 

[in]指针到指定的对象PointF闭合的基数样条曲线的坐标数组.对PointF对象数组必须包含至少三个元素.

 

count

 

[in]整数,指定的点的数组元素个数.

 

tension

 

[in]简单精度数,指定如何紧密的曲线弯曲的闭合的基数样条曲线的坐标.

 

返回值

 

如果该方法成功,则返回Ok,这是对Status枚举元素.

如果这个方法失败,它返回一个枚举的其他元素的Status.

 

备注

 

每个结束点是下一个基数样条的起点.在封闭的基数样条曲线中,曲线继续通过点数组中的最后一点,并与数组中的第一个点连接.

 

引用文件

 

CGpBitmap.inc (include CGdiPlus.inc)

 

示例

 

' ========================================================================================

' The following example draws a closed cardinal spline.

' ========================================================================================

SUB Example_DrawClosedCurve (BYVAL hdc AS HDC)

 

  ' // Create a graphics object from the window device context

  DIM graphics AS CGpGraphics = hdc

  ' // Get the DPI scaling ratio

  DIM rxRatio AS SINGLE = graphics.GetDpiX / 96

  DIM ryRatio AS SINGLE = graphics.GetDpiY / 96

  ' // Set the scale transform

  graphics.ScaleTransform(rxRatio, ryRatio)

 

  ' // Define a Pen object and an array of PointF objects.

  DIM greenPen AS CGpPen = GDIP_ARGB(255, 0, 255, 0)

  DIM point1 AS GpPointF : point1.x = 100.0 : point1.y = 100.0

  DIM point2 AS GpPointF : point2.x = 200.0 : point2.y = 50.0

  DIM point3 AS GpPointF : point3.x = 400.0 : point3.y = 10.0

  DIM point4 AS GpPointF : point4.x = 500.0 : point4.y = 100.0

  DIM point5 AS GpPointF : point5.x = 600.0 : point5.y = 200.0

  DIM point6 AS GpPointF : point6.x = 700.0 : point6.y = 400.0

  DIM point7 AS GpPointF : point7.x = 500.0 : point7.y = 500.0

 

  DIM curvePoints(6) AS GpPointF

  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.

  graphics.DrawClosedCurve(@greenPen, @curvePoints(0), 7, 1.0)

 

  ' // Draw the points in the curve.

  DIM redBrush AS CGpSolidBrush = GDIP_ARGB(255, 255, 0, 0)

  graphics.FillEllipse(@redBrush, 95, 95, 10, 10)

  graphics.FillEllipse(@redBrush, 495, 95, 10, 10)

  graphics.FillEllipse(@redBrush, 495, 495, 10, 10)

  graphics.FillEllipse(@redBrush, 195, 45, 10, 10)

  graphics.FillEllipse(@redBrush, 395, 5, 10, 10)

  graphics.FillEllipse(@redBrush, 595, 195, 10, 10)

  graphics.FillEllipse(@redBrush, 695, 395, 10, 10)

 

END SUB

' ========================================================================================