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
该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
' ========================================================================================