rotate (Matrix.rotate method) -- Flash CS3

Sets the values in the current matrix so that the matrix can be used to apply a rotation transformation.

The rotate() method alters the a, b, c, and d properties of the Matrix object. In matrix notation this is shown as follows:

Parameters

Example

The following example shows how the rotate() method rotates rectangleMc 30˚ clockwise. Applying myMatrix to rectangleMc resets its _x value, leaving you to reset it to 100 manually.

import flash.geom.Matrix;
import flash.geom.Transform;

var myMatrix:Matrix = new Matrix();
trace(myMatrix.toString()); // (a=1, b=0, c=0, d=1, tx=0, ty=0)

var degrees:Number = 30;
var radians:Number = (degrees/180) * Math.PI;
myMatrix.rotate(radians);
trace(myMatrix.toString()); // (a=0.866025403784439, b=0.5, c=-0.5, d=0.866025403784439, tx=0, ty=0)

var rectangleMc:MovieClip = createRectangle(20, 80, 0xFF0000);
trace(rectangleMc._x); // 0
rectangleMc._x = 100;
trace(rectangleMc._x); // 100

var rectangleTrans:Transform = new Transform(rectangleMc);
rectangleTrans.matrix = myMatrix;
trace(rectangleMc._x); // 0
rectangleMc._x = 100;
trace(rectangleMc._x); // 100

function createRectangle(width:Number, height:Number, color:Number):MovieClip {
    var depth:Number = this.getNextHighestDepth();
    var mc:MovieClip = this.createEmptyMovieClip("mc_" + depth, depth);
    mc.beginFill(color);
    mc.lineTo(0, height);
    mc.lineTo(width, height);
    mc.lineTo(width, 0);
    mc.lineTo(0, 0);
    return mc;
}

The previous example uses the _x property of the MovieClip object to position rectangleMc. Generally, when dealing with Matrix object positioning, mixing positioning techniques is considered poor format. The previous example written in correct syntax would concatenate a translation Matrix to myMatrix to change the horizontal location of rectangleMc. The following example demonstrates this.

import flash.geom.Matrix;
import flash.geom.Transform;

var myMatrix:Matrix = new Matrix();
trace(myMatrix.toString()); // (a=1, b=0, c=0, d=1, tx=0, ty=0)

var degrees:Number = 30;
var radians:Number = (degrees/180) * Math.PI;
myMatrix.rotate(radians);
trace(myMatrix.toString()); // (a=0.866025403784439, b=0.5, c=-0.5, d=0.866025403784439, tx=0, ty=0)

var translateMatrix:Matrix = new Matrix();
translateMatrix.translate(100, 0);
myMatrix.concat(translateMatrix);
trace(myMatrix.toString()); // (a=0.866025403784439, b=0.5, c=-0.5, d=0.866025403784439, tx=100, ty=0)

var rectangleMc:MovieClip = createRectangle(20, 80, 0xFF0000);
trace(rectangleMc._x); // 0
rectangleMc._x = 100;
trace(rectangleMc._x); // 100

var rectangleTrans:Transform = new Transform(rectangleMc);
rectangleTrans.matrix = myMatrix;
trace(rectangleMc._x); // 100

function createRectangle(width:Number, height:Number, color:Number):MovieClip {
    var depth:Number = this.getNextHighestDepth();
    var mc:MovieClip = this.createEmptyMovieClip("mc_" + depth, depth);
    mc.beginFill(color);
    mc.lineTo(0, height);
    mc.lineTo(width, height);
    mc.lineTo(width, 0);
    mc.lineTo(0, 0);
    return mc;
}