as中matrix反向求缩放旋转的类。
// Copyright © 2007. Adobe Systems Incorporated. All Rights Reserved.
package fl.motion
{
import flash.geom.*;
/**
* The MatrixTransformer class contains methods for modifying individual properties of a transformation matrix:
* horizontal and vertical scale, horizontal and vertical skew, and rotation.
* This class also has methods for rotating around a given transformation point rather than the typical (0, 0) point.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword MatrixTransformer, Copy Motion as ActionScript
* @see ../../motionXSD.html Motion XML Elements
* @see flash.geom
*/
public class MatrixTransformer
{
/**
* Calculates the horizontal scale present in a matrix.
*
* @param m A Matrix instance.
*
* @return The horizontal scale.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getScaleX(m:Matrix):Number
{
return Math.sqrt(m.a*m.a + m.b*m.b);
}
/**
* Changes the horizontal scale in a matrix.
*
* @param m A Matrix instance to be modified.
*
* @param scaleX The new horizontal scale.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setScaleX(m:Matrix, scaleX:Number):void
{
var oldValue:Number = getScaleX(m);
// avoid division by zero
if (oldValue)
{
var ratio:Number = scaleX / oldValue;
m.a *= ratio;
m.b *= ratio;
}
else
{
var skewYRad:Number = getSkewYRadians(m);
m.a = Math.cos(skewYRad) * scaleX;
m.b = Math.sin(skewYRad) * scaleX;
}
}
/**
* Calculates the vertical scale present in a matrix.
*
* @param m A Matrix instance.
*
* @return The vertical scale.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getScaleY(m:Matrix):Number
{
return Math.sqrt(m.c*m.c + m.d*m.d);
}
/**
* Changes the vertical scale in a matrix.
*
* @param m A Matrix instance to be modified.
*
* @param scaleY The new vertical scale.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setScaleY(m:Matrix, scaleY:Number):void
{
var oldValue:Number = getScaleY(m);
// avoid division by zero
if (oldValue)
{
var ratio:Number = scaleY / oldValue;
m.c *= ratio;
m.d *= ratio;
}
else
{
var skewXRad:Number = getSkewXRadians(m);
m.c = -Math.sin(skewXRad) * scaleY;
m.d = Math.cos(skewXRad) * scaleY;
}
}
/**
* Calculates the angle of horizontal skew present in a matrix, in radians.
*
* @param m A Matrix instance.
*
* @return The angle of horizontal skew, in radians.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getSkewXRadians(m:Matrix):Number
{
return Math.atan2(-m.c, m.d);
}
/**
* Changes the horizontal skew in a matrix.
*
* @param m A Matrix instance to be modified.
*
* @param skewX The new horizontal skew, in radians.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setSkewXRadians(m:Matrix, skewX:Number):void
{
var scaleY:Number = getScaleY(m);
m.c = -scaleY * Math.sin(skewX);
m.d = scaleY * Math.cos(skewX);
}
/**
* Calculates the angle of vertical skew present in a matrix, in radians.
*
* @param m A Matrix instance.
*
* @return The angle of vertical skew, in radians.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getSkewYRadians(m:Matrix):Number
{
return Math.atan2(m.b, m.a);
}
/**
* Changes the vertical skew in a matrix.
*
* @param m A Matrix instance to be modified.
*
* @param skewY The new vertical skew, in radians.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setSkewYRadians(m:Matrix, skewY:Number):void
{
var scaleX:Number = getScaleX(m);
m.a = scaleX * Math.cos(skewY);
m.b = scaleX * Math.sin(skewY);
}
/**
* Calculates the angle of horizontal skew present in a matrix, in degrees.
*
* @param m A Matrix instance.
*
* @return The angle of horizontal skew, in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getSkewX(m:Matrix):Number
{
return Math.atan2(-m.c, m.d) * (180/Math.PI);
}
/**
* Changes the horizontal skew in a matrix.
*
* @param m A Matrix instance to be modified.
*
* @param skewX The new horizontal skew, in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setSkewX(m:Matrix, skewX:Number):void
{
setSkewXRadians(m, skewX*(Math.PI/180));
}
/**
* Calculates the angle of vertical skew present in a matrix, in degrees.
*
* @param m A Matrix instance.
*
* @return The angle of vertical skew, in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getSkewY(m:Matrix):Number
{
return Math.atan2(m.b, m.a) * (180/Math.PI);
}
/**
* Changes the vertical skew in a matrix.
*
* @param m A Matrix instance to be modified.
*
* @param skewX The new vertical skew, in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setSkewY(m:Matrix, skewY:Number):void
{
setSkewYRadians(m, skewY*(Math.PI/180));
}
/**
* Calculates the angle of rotation present in a matrix, in radians.
* If the horizontal and vertical skews are not equal,
* the vertical skew value is used.
*
* @param m A Matrix instance.
*
* @return The angle of rotation, in radians.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getRotationRadians(m:Matrix):Number
{
return getSkewYRadians(m);
}
/**
* Changes the angle of rotation in a matrix.
* If the horizontal and vertical skews are not equal,
* the vertical skew is set to the rotation value
* and the horizontal skew is increased by the difference between the
* old rotation and the new rotation.
* This matches the rotation behavior in Flash Player.
*
* @param m A Matrix instance.
*
* @param rotation The angle of rotation, in radians.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setRotationRadians(m:Matrix, rotation:Number):void
{
var oldRotation:Number = getRotationRadians(m);
var oldSkewX:Number = getSkewXRadians(m);
setSkewXRadians(m, oldSkewX + rotation-oldRotation);
setSkewYRadians(m, rotation);
}
/**
* Calculates the angle of rotation present in a matrix, in degrees.
* If the horizontal and vertical skews are not equal,
* the vertical skew value is used.
* This matches the rotation behavior in Flash Player.
*
* @param m A Matrix instance.
*
* @return The angle of rotation, in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function getRotation(m:Matrix):Number
{
return getRotationRadians(m)*(180/Math.PI);
}
/**
* Changes the angle of rotation in a matrix.
* If the horizontal and vertical skews are not equal,
* the vertical skew is set to the rotation value
* and the horizontal skew is increased by the difference between the
* old rotation and the new rotation.
* This matches the rotation behavior in Flash Player.
*
* @param m A Matrix instance.
*
* @param rotation The angle of rotation, in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function setRotation(m:Matrix, rotation:Number):void
{
setRotationRadians(m, rotation*(Math.PI/180));
}
/**
* Rotates a matrix about a point defined inside the matrix's transformation space.
* This can be used to rotate a movie clip around a transformation point inside itself.
*
* @param m A Matrix instance.
*
* @param x The x coordinate of the point.
*
* @param y The y coordinate of the point.
*
* @param angleDegrees The angle of rotation in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function rotateAroundInternalPoint(m:Matrix, x:Number, y:Number, angleDegrees:Number):void
{
var point:Point = new Point(x, y);
point = m.transformPoint(point);
m.tx -= point.x;
m.ty -= point.y;
m.rotate(angleDegrees*(Math.PI/180));
m.tx += point.x;
m.ty += point.y;
}
/**
* Rotates a matrix about a point defined outside the matrix's transformation space.
* This can be used to rotate a movie clip around a transformation point in its parent.
*
* @param m A Matrix instance.
*
* @param x The x coordinate of the point.
*
* @param y The y coordinate of the point.
*
* @param angleDegrees The angle of rotation in degrees.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function rotateAroundExternalPoint(m:Matrix, x:Number, y:Number, angleDegrees:Number):void
{
m.tx -= x;
m.ty -= y;
m.rotate(angleDegrees*(Math.PI/180));
m.tx += x;
m.ty += y;
}
/**
* Moves a matrix as necessary to align an internal point with an external point.
* This can be used to match a point in a transformed movie clip with one in its parent.
*
* @param m A Matrix instance.
*
* @param internalPoint A Point instance defining a position within the matrix's transformation space.
*
* @param externalPoint A Point instance defining a reference position outside the matrix's transformation space.
* @playerversion Flash 9.0.28.0
* @playerversion AIR 1.0
* @productversion Flash CS3
* @langversion 3.0
* @keyword Matrix, Copy Motion as ActionScript
* @see flash.geom.Matrix
*/
public static function matchInternalPointWithExternal(m:Matrix, internalPoint:Point, externalPoint:Point):void
{
var internalPointTransformed:Point = m.transformPoint(internalPoint);
var dx:Number = externalPoint.x - internalPointTransformed.x;
var dy:Number = externalPoint.y - internalPointTransformed.y;
m.tx += dx;
m.ty += dy;
}
}
}
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