Matrix.TransformPoints Method (Point[])

The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, an Paint event object. The code performs the following actions:

• Creates an array of points that form a rectangle.

• Draws this array of points (to the screen prior to applying a scaling transform (the blue rectangle).

• Creates a matrix and scales it by 3 in the x-axis and 2 in the y-axis.

• Applies this matrix transform to the array of points.

• Draws the transformed array to the screen (the red rectangle).

Notice that the red rectangle has been scaled by a factor of 3 in the x-axis and by 2 in the y-axis, including the upper left-hand corner of the rectangle (the beginning point of the rectangle).

public void TransformPointsExample(PaintEventArgs e)
{
    Pen myPen = new Pen(Color.Blue, 1);
    Pen myPen2 = new Pen(Color.Red, 1);

    // Create an array of points.
    Point[] myArray =
             {
                 new Point(20, 20),
                 new Point(120, 20),
                 new Point(120, 120),
                 new Point(20, 120),
                 new Point(20,20)
             };

    // Draw the Points to the screen before applying the
    // transform.
    e.Graphics.DrawLines(myPen, myArray);

    // Create a matrix and scale it.
    Matrix myMatrix = new Matrix();
    myMatrix.Scale(3, 2, MatrixOrder.Append);
    myMatrix.TransformPoints(myArray);

    // Draw the Points to the screen again after applying the
    // transform.
    e.Graphics.DrawLines(myPen2, myArray);
}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference