/*  -*-c++-*-
 *  Copyright (C) 2008 Cedric Pinson <cedric.pinson@plopbyte.net>
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSGANIMATION_VERTEX_INFLUENCE
#define OSGANIMATION_VERTEX_INFLUENCE 1

#include <osg/Object>
#include <osgAnimation/Export>
#include <map>
#include <vector>
#include <string>

namespace osgAnimation
{
    // first is bonename, and second the weight
    struct BoneWeight: public std::pair<std::string, float>
    {
        BoneWeight( std::string f,float s):
        std::pair<std::string,float>(f,s){}
        inline const std::string& getBoneName()const{return first;}
        inline void setBoneName(const std::string&s){first=s;}
        inline const float &getWeight()const{return second;}
        inline void setWeight(float i){second=i;}
    };
    // first is vertex index, and second the weight
    struct IndexWeight: public std::pair<unsigned int, float>
    {
        IndexWeight( unsigned int f,float s): std::pair<unsigned int,float>(f,s){}
        inline const unsigned int& getIndex()const{return first;}
        inline void setIndex(unsigned int i){first=i;}
        inline const float &getWeight()const{return second;}
        inline void setWeight(float i){second=i;}
    };

    typedef std::vector<IndexWeight> VertexList;
    class OSGANIMATION_EXPORT BoneInfluenceList : public VertexList
    {
    public:
        const std::string& getBoneName() const { return _name;}
        void setBoneName(const std::string& name) { _name = name;}

    protected:
        // the name is the bone to link to
        std::string _name;
    };

    class VertexInfluenceMap : public std::map<std::string, BoneInfluenceList> , public osg::Object
    {
    public:
        META_Object(osgAnimation, VertexInfluenceMap);

        VertexInfluenceMap() {}
        VertexInfluenceMap(const osgAnimation::VertexInfluenceMap& org, const osg::CopyOp& copyop):
            std::map<std::string, BoneInfluenceList>(org),
            osg::Object(org, copyop)
        {}
    };


    // this class manage VertexInfluence database by mesh
    // reference bones per vertex ...
    class OSGANIMATION_EXPORT VertexInfluenceSet
    {
    public:
        typedef std::vector<BoneInfluenceList> BoneToVertexList;

        class BoneWeight
        {
        public:
            BoneWeight(const std::string& name, float weight) : _boneName(name), _weight(weight) {}
            BoneWeight(const BoneWeight &bw2) : _boneName(bw2._boneName), _weight(bw2._weight) {}
            const std::string& getBoneName() const { return _boneName; }
            float getWeight() const { return _weight; }
            void setWeight(float weight) { _weight = weight; }
            bool operator==(const BoneWeight& b) const { return (_boneName == b.getBoneName() && _weight == b.getWeight()); }

        protected:
            std::string _boneName;
            float _weight;
        };

        typedef std::vector<BoneWeight> BoneWeightList;
        typedef std::vector<BoneWeightList> VertIDToBoneWeightList;

        class VertexGroup
        {
        public:
            // set Influences of the VertexGroup
            void setBones(BoneWeightList& bones) { _bones = bones;}
            const BoneWeightList& getBones() const { return _bones;}
            // set Vertex Indices of the VertexGroup
            std::vector<unsigned  int>& getVertexes() { return _vertexes;}
            const std::vector<unsigned  int>& getVertexes() const { return _vertexes;}
        protected:
            std::vector<unsigned int> _vertexes;
            BoneWeightList _bones; // here we could limit matrix operation by caching (weight * matrix)
        };

        typedef std::vector<VertexGroup> UniqVertexGroupList;
        /** construct a vector of unique VertexGroups and their influences**/
        void buildUniqVertexGroupList();
        /** return a list of unique VertexGroups and their influences**/
        const UniqVertexGroupList& getUniqVertexGroupList() const { return _uniqVertexSetToBoneSet;}
        void addVertexInfluence(const BoneInfluenceList& v);
        void buildVertex2BoneList(unsigned int numvertices);
        void clear();

        const VertIDToBoneWeightList& getVertexToBoneList() const;
    protected:
        BoneToVertexList _bone2Vertexes;
        VertIDToBoneWeightList _vertex2Bones;
        UniqVertexGroupList _uniqVertexSetToBoneSet;
    };

}

#endif