* Copyright 2012 Google Inc.
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
Many of SVG's graphics operations utilize 2x3 matrices of the form:
[a c e] [b d f]
which, when expanded into a 3x3 matrix for the purposes of matrix arithmetic, become:
[a c e] [b d f] [0 0 1]
SVGMatrix object can be designated as read only, which means that attempts to modify the object will result in an exception being thrown.
Post-multiplies a rotation transformation on the current matrix and returns the resulting matrix. The rotation angle is determined by taking (+/-) atan(y/x). The direction of the vector (x, y) determines whether the positive or negative angle value is used.
SVG_INVALID_VALUE_ERRis raised if one of the parameters has an invalid value.