First pass at Rect Effect

include/core/SkMatrix.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkMatrix_DEFINED
@@ skipping 72 matching lines @@
     bool hasPerspective() const {
         return SkToBool(this->getPerspectiveTypeMaskOnly() &
                         kPerspective_Mask);
     }
 
     /** Returns true if the matrix contains only translation, rotation or uniform scale
         Returns false if other transformation types are included or is degenerate
      */
     bool isSimilarity(SkScalar tol = SK_ScalarNearlyZero) const;
 
+    /** Returns true if the matrix contains only translation, rotation or scale
+        (non-uniform scale is allowed).
+        Returns false if other transformation types are included or is degenerate
+     */
+    bool preservesRightAngles(SkScalar tol = SK_ScalarNearlyZero) const;
+
     enum {
         kMScaleX,
         kMSkewX,
         kMTransX,
         kMSkewY,
         kMScaleY,
         kMTransY,
         kMPersp0,
         kMPersp1,
         kMPersp2
@@ skipping 556 matching lines @@
     static void RotTrans_pts(const SkMatrix&, SkPoint dst[], const SkPoint[],
                              int count);
     static void Persp_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], int);
 
     static const MapPtsProc gMapPtsProcs[];
 
     friend class SkPerspIter;
 };
 
 #endif