Matrix.ScalePrepend(Double, Double) Method

Definition

Prepends the specified scale vector to this Matrix structure.

public:
 void ScalePrepend(double scaleX, double scaleY);
public void ScalePrepend (double scaleX, double scaleY);
member this.ScalePrepend : double * double -> unit
Public Sub ScalePrepend (scaleX As Double, scaleY As Double)

Parameters

scaleX
Double

The value by which to scale this Matrix structure along the x-axis.

scaleY
Double

The value by which to scale this Matrix structure along the y-axis.

Examples

The following example shows how to prepend a scale to a Matrix structure.


private Matrix scalePrependExample()
{
    Matrix myMatrix = new Matrix(5, 10, 15, 20, 25, 30);
    
    // Prepend a scale ab with a horizontal factor of 2
    // and a vertical factor of 4 about the origin.
    // After this operation,
    // myMatrix is equal to (10, 20, 60, 80, 25, 30)
    myMatrix.ScalePrepend(2, 4);
    
    return myMatrix;

}

private Matrix scalePrependAboutPointExample()
{
    Matrix myMatrix = new Matrix(5, 10, 15, 20, 25, 30);
    
    // Prepend a scale with a horizontal factor of 2
    // and a vertical factor of 4 about the 
    // point (100,100).
    // After this operation,
    // myMatrix is equal to (10, 20, 60, 80, -4975, -6970)
    myMatrix.ScaleAtPrepend(2, 4, 100, 100);
    
    return myMatrix;

}        

Remarks

In a composite transformation, the order of individual transformations is important. For example, if you first rotate, then scale, then translate, you get a different result than if you first translate, then rotate, then scale. One reason order is significant is that transformations like rotation and scaling are done with respect to the origin of the coordinate system. 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. 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.

Applies to

See also