text: //-*****************************************************************************
  //
  // Copyright (c) 2009-2010,
  //  Sony Pictures Imageworks Inc. and
  //  Industrial Light & Magic, a division of Lucasfilm Entertainment Company Ltd.
  //
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  // *       Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  // *       Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  // *       Neither the name of Sony Pictures Imageworks, nor
  // Industrial Light & Magic, nor the names of their contributors may be used
  // to endorse or promote products derived from this software without specific
  // prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  //-*****************************************************************************
  
  #ifndef _AlembicExport_MayaTransformWriter_h_
  #define _AlembicExport_MayaTransformWriter_h_
  
  #include "Foundation.h"
  
  #include <Alembic/AbcGeom/OXform.h>
  #include <Alembic/AbcGeom/XformOp.h>
  
  #include "AttributesWriter.h"
  
  // AnimChan contains what animated plugs to get as a double, and the helper
  // info about what operation and which channel to set in mSample
  struct AnimChan
  {
      MPlug plug;
  
      // extra value to multiply the data off of the plug by, used to invert
      // certain operations, and convert radians to degrees
      double scale;
  
      uint32_t opNum;
      uint32_t channelNum;
  };
  
  // Writes an MFnTransform
  class MayaTransformWriter
  {
    public:
  
      MayaTransformWriter(double iFrame, Alembic::Abc::OObject & iParent,
          MDagPath & iDag, 
          uint32_t iTimeIndex,
          bool addWorld, bool iWriteVisibility);
  
      MayaTransformWriter(double iFrame, MayaTransformWriter & iParent,
          MDagPath & iDag,
          uint32_t iTimeIndex,
          bool iWriteVisibility);
  
      ~MayaTransformWriter();
      void write(double iFrame);
      bool isAnimated() const;
      Alembic::Abc::OObject getObject() {return mSchema.getObject();};
      AttributesWriterPtr getAttrs() {return mAttrs;};
  
    private:
  
      Alembic::AbcGeom::OXformSchema mSchema;
      AttributesWriterPtr mAttrs;
  
      void pushTransformStack(double iFrame, const MFnTransform & iTrans);
  
      void pushTransformStack(double iFrame, const MFnIkJoint & iTrans);
  
      Alembic::AbcGeom::XformSample mSample;
  
      std::vector < AnimChan > mAnimChanList;
      MPlug mInheritsPlug;
  };
  
  typedef boost::shared_ptr < MayaTransformWriter > MayaTransformWriterPtr;
  
  #endif  // _AlembicExport_MayaTransformWriter_h_
  