Adobe FLEX 2-PROGRAMMING ACTIONSCRIPT 3.0 Manual page 424

Defining Matrix objects
Although you could define a matrix by directly adjusting the properties ( , , , , , ) of a
a b c d tx ty
Matrix object, it is easier to use the method. This method includes parameters
createBox()
that let you directly define the scaling, rotation, and translation effects of the resulting matrix.
For example, the following code creates a Matrix object that has the effect of scaling an object
horizontally by 2.0, scaling it vertically by 3.0, rotating it by 45 degrees, moving (translating)
it 10 pixels to the right, and moving it 20 pixels down:
var matrix:Matrix = new Matrix();
var scaleX:Number = 2.0;
var scaleY:Number = 3.0;
var rotation:Number = 2 * Math.PI * (45 / 360);
var tx:Number = 10;
var ty:Number = 20;
matrix.createBox(scaleX, scaleY, rotation, tx, ty);
You can also adjust the scaling, rotation, and translation effects of a Matrix object by using the
, , and methods. Note that these methods combine with the
scale() rotate() translate()
values of the existing Matrix object. For instance, the following code sets a Matrix object that
scales an object by a factor of 4 and rotates it 60 degrees, since the and
scale() rotate()
methods are called twice:
var matrix:Matrix = new Matrix();
var rotation:Number = 2 * Math.PI * (30 / 360); // 30°
var scaleFactor:Number = 2;
matrix.scale(scaleFactor, scaleFactor);
matrix.rotate(rotation);
matrix.scale(scaleX, scaleY);
matrix.rotate(rotation);
myDisplayObject.transform.matrix = matrix;
To apply a skew transformation to a Matrix object, adjust its or property. Adjusting the
b c b
property skews the matrix vertically, and adjusting the property skews the matrix
c
horizontally. The following code skews the Matrix object vertically by a factor of 2:
myMatrix
var skewMatrix:Matrix = new Matrix();
skewMatrix.b = Math.tan(2);
myMatrix.concat(skewMatrix);
You can apply a Matrix transformation to the property of a display object. For
transform
example, the following code applies a matrix transformation to a display object named
:
myDisplayObject
var matrix:Matrix = myDisplayObject.transform.matrix;
var scaleFactor:Number = 2;
var rotation:Number = 2 * Math.PI * (60 / 360); // 60°
matrix.scale(scaleFactor, scaleFactor);
424 Working with Geometry