Matrix.RotateAtPrepend(Double, Double, Double) 方法

定義

在這個 Matrix 結構之前加上繞著指定的點進行的所指定角度的旋轉。Prepends a rotation of the specified angle at the specified point to this Matrix structure.

public:
 void RotateAtPrepend(double angle, double centerX, double centerY);
public void RotateAtPrepend (double angle, double centerX, double centerY);
member this.RotateAtPrepend : double * double * double -> unit
Public Sub RotateAtPrepend (angle As Double, centerX As Double, centerY As Double)

參數

angle
Double

旋轉角度 (以度數為單位)。The rotation angle, in degrees.

centerX
Double

旋轉中心的 X 座標。The x-coordinate of the rotation center.

centerY
Double

旋轉中心的 Y 座標。The y-coordinate of the rotation center.

範例

下列範例將示範如何在中預先執行旋轉 MatrixThe following example shows how to prepend a rotation to a Matrix.

private Matrix prependRotateExample()
{

    Matrix myMatrix = new Matrix(5, 10, 15, 20, 25, 30);

    // Prepend a 90 degree rotation about the origin.
    // myMatrix is now equal to  (15,20,-5,-10,25,30).
    myMatrix.RotatePrepend(90);

    return myMatrix;
}

private Matrix prependRotateAboutPointExample()
{

    Matrix myMatrix = new Matrix(5, 10, 15, 20, 25, 30);

    // Prepend a 90 degree rotation about the 
    // point (100,100). 
    // myMatrix is now equal to  (15,20,-5,-10,1025,2030).
    myMatrix.RotateAtPrepend(90, 100, 100);

    return myMatrix;
}

備註

在複合轉換中,個別轉換的順序很重要。In a composite transformation, the order of individual transformations is important. 例如,如果您第一次旋轉,然後進行調整,然後轉譯,則會得到不同的結果,而不是您第一次轉譯、接著旋轉然後調整規模。For example, if you first rotate, then scale, then translate, you get a different result than if you first translate, then rotate, then scale. 其中一個原因是很重要的是,旋轉和縮放等轉換是針對座標系統的原點進行的。One reason order is significant is that transformations like rotation and scaling are done with respect to the origin of the coordinate system. 調整位於原點中央的物件會產生不同的結果,而不是縮放已從原點移出的物件。Scaling an object that is centered at the origin produces a different result than scaling an object that has been moved away from the origin. 同樣地,旋轉位於原點中央的物件會產生不同的結果,而不是旋轉離開來源的物件。Similarly, rotating an object that is centered at the origin produces a different result than rotating an object that has been moved away from the origin.

適用於