Vec3Packed

/* -*-c++-*- 
*/
//****************************************************************************//
// loader.cpp                                                                 //
// Copyright (C) 2001, 2002 Bruno 'Beosil' Heidelberger                       //
//****************************************************************************//
// This library is free software; you can redistribute it and/or modify it    //
// under the terms of the GNU Lesser General Public License as published by   //
// the Free Software Foundation; either version 2.1 of the License, or (at    //
// your option) any later version.                                            //
//****************************************************************************//

/*****************************************************************************/
/* Loads a core compressed keyframe instance.
 *
 * This function loads a core compressed keyframe instance from a data source.
 *
 * @param dataSrc The data source to load the core compressed keyframe instance from.
 *
 * @return One of the following values:
 *         \li a pointer to the core keyframe
 *         \li \b 0 if an error happened
 * Authors
 *         Igor Kravchenko
 *         Cedric Pinson <mornifle@plopbyte.net>
 *****************************************************************************/


#ifndef OSGANIMATION_PACKED_H
#define OSGANIMATION_PACKED_H

#include <float.h>
#include <vector>
#include <osg/Vec3>
#include <osg/Math>

namespace osgAnimation 
{


    struct Vec3Packed
    {
        typedef unsigned int uint32_t;
        uint32_t m32bits;
        Vec3Packed(uint32_t val): m32bits(val) {}
        Vec3Packed(): m32bits(0) {}

        void uncompress(const osg::Vec3& scale, const osg::Vec3& min, osg::Vec3& result) const 
        {
            uint32_t pt[3];
            pt[0] = m32bits & 0x7ff;
            pt[1] = (m32bits >> 11) & 0x7ff;
            pt[2] = m32bits >> 22;
            result[0] = scale[0] * pt[0] + min[0];
            result[1] = scale[1] * pt[1] + min[1];
            result[2] = scale[2] * pt[2] + min[2];
        }
    
        void compress(const osg::Vec3f& src, const osg::Vec3f& min, const osg::Vec3f& scaleInv) 
        {
            uint32_t srci[3];
            srci[0] = osg::minimum(static_cast<uint32_t>(((src[0] - min[0] )*scaleInv[0])), uint32_t(2047));
            srci[1] = osg::minimum(static_cast<uint32_t>(((src[1] - min[1] )*scaleInv[1])), uint32_t(2047));
            srci[2] = osg::minimum(static_cast<uint32_t>(((src[2] - min[2] )*scaleInv[2])), uint32_t(1023));
            m32bits = srci[0] + (srci[1] << 11) + (srci[2] << 22);
        }
    };

    struct Vec3ArrayPacked
    {
        std::vector<Vec3Packed> mVecCompressed;
        osg::Vec3 mMin;
        osg::Vec3 mScale;
        osg::Vec3 mScaleInv;

        void analyze(const std::vector<osg::Vec3>& src) 
        {
            //analyze the keys
            mMin.set(FLT_MAX, FLT_MAX, FLT_MAX);
            osg::Vec3 maxp(-FLT_MAX, -FLT_MAX, -FLT_MAX);
            int nb = (int)src.size();
            for(int i = 0; i < nb; i++) 
            {
                const osg::Vec3 &pos = src[i];
                for(int j = 0; j < 3; j++) 
                {
                    maxp[j] = osg::maximum(pos[j],maxp[j]);
                    mMin[j] = osg::minimum(pos[j],mMin[j]);
                }
            }

            osg::Vec3 diff = maxp - mMin;
            mScaleInv.set(0,0,0);
            if (diff[0] != 0)
                mScaleInv[0] = 2047.0/diff[0];

            if (diff[1] != 0)
                mScaleInv[1] = 2047.0/diff[1];

            if (diff[2] != 0)
                mScaleInv[2] = 1023.0/diff[2];

            mScale[0] = diff[0] / 2047;
            mScale[1] = diff[1] / 2047;
            mScale[2] = diff[2] / 1023;
        }

        void compress(const std::vector<osg::Vec3>& src) 
        {
            mVecCompressed.resize(src.size());
            // save all core keyframes
            for(int i = 0; i < (int)src.size(); i++)
                mVecCompressed[i].compress(src[i], mMin, mScaleInv);
        }
    };

}

#endif