导航:  GdiPlus Classes > GdiPlus Classes > CGpBrush Class > CGpTextureBrush Class > TextureBrush Object >

RotateTransform

上一页返回章节概述下一页

描述

 

更新纹理画笔的当前变换矩阵的产品本身和旋转矩阵.

 

C++ Syntax

 

Status RotateTransform(

[in]  REAL angle,

[in]  MatrixOrder order

);

 

FreeBASIC 语法

 

FUNCTION RotateTransform ( _

   BYVAL angle AS SINGLE, _

   BYVAL order AS MatrixOrder = MatrixOrderPrepend _

) AS GpStatus

 

参数

 

angle

 

[in]简单精度数指定的角度,旋转.

 

order

 

MatrixOrder指定相乘的顺序[in, optional]元.MatrixOrderPrepend指定传递矩阵是在左边,和MatrixOrderAppend指定传递矩阵是正确的.默认值是MatrixOrderPrepend.

 

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

 

一个3?矩阵可以存储任意序列的仿射变换.如果你有几个3?矩阵,其中每一个表示仿射变换,这些矩阵的产品是一个单一的3?表示整个变换序列的矩阵.该产品表示的变换称为复合变换.例如,假设矩阵R表示一个旋转,和矩阵T代表翻译.如果矩阵M是产品RT,然后矩阵M代表复合变换:先旋转,然后翻译.

矩阵乘法的顺序是重要的.在一般情况下,矩阵的乘积RT不是矩阵的乘积TR相同.在上一段中给出的例子中,由RT复合变换(旋转,然后翻译)不为代表的TR复合变换相同(第一次翻译,然后旋转).

 

引用文件

 

CGpBrush.inc (include CGdiPlus.inc)

 

示例

 

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

' The following example creates a texture brush and sets the transformation of the brush.

' The code then uses the transformed brush to fill a rectangle.

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

SUB Example_RotateTransform (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)

 

  ' // Create a texture brush, and set its transformation.

  DIM pImage AS CGpImage = "HouseAndTree.gif"

  DIM textureBrush AS CGpTextureBrush = @pImage

  textureBrush.ScaleTransform(3, 1)

  textureBrush.RotateTransform(30, MatrixOrderAppend)

  graphics.FillEllipse(@textureBrush, 0, 0, 400, 200)

 

END SUB

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