artkpFixedBase_generic.h

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/* ========================================================================
 * PROJECT: ARToolKitPlus
 * ========================================================================
 * This work is based on the original ARToolKit developed by
 *   Hirokazu Kato
 *   Mark Billinghurst
 *   HITLab, University of Washington, Seattle
 * http://www.hitl.washington.edu/artoolkit/
 *
 * Copyright of the derived and new portions of this work
 *     (C) 2006 Graz University of Technology
 *
 * This framework is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This framework 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
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this framework; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * For further information please contact 
 *   Dieter Schmalstieg
 *   <schmalstieg@icg.tu-graz.ac.at>
 *   Graz University of Technology, 
 *   Institut for Computer Graphics and Vision,
 *   Inffeldgasse 16a, 8010 Graz, Austria.
 * ========================================================================
 ** @author   Daniel Wagner
 *
 * $Id$
 * @file
 * ======================================================================== */


#ifndef __ARTKPFIXEDBASE_GENERIC_HEADERFILE__
#define __ARTKPFIXEDBASE_GENERIC_HEADERFILE__

#include <assert.h>


// Generic MATHBASE implementation for all
// platforms. This implementation is totally
// unoptimized.
// (e.g. using the sin() function from math.h)
//
template <int PBITS_, int CHECK_>
class artkpFixedBase_generic
{
public:
        enum {
                PBITS = PBITS_,
                CHECK = CHECK_
        };


        static void checkInt(int nInteger)
        {
                __int64 v64 = ((__int64)nInteger) << PBITS;
                if(v64 != int(v64))
                {
                        assert(false && "Integer to Fixed-Point conversion failed: the target's range was overflowed");
                };
        }

        static void checkFloat(float nFloat)
        {
                __int64 v64 = (__int64)(nFloat *  ((float)(1 << PBITS) + 0.5f));
                if(v64 != int(v64))
                {
                        assert(false && "Float to Fixed-Point conversion failed: the target's range was overflowed");
                };
        }

        static void checkDouble(double nDouble)
        {
                __int64 v64 = (__int64)(nDouble *  ((double)(1 << PBITS) + 0.5f));
                if(v64 != int(v64))
                {
                        assert(false && "Double to Fixed-Point conversion failed: the target's range was overflowed");
                };
        }

        static float floatFromFixed(int nFixed)
        {
                return nFixed/(float)(1 << PBITS);
        }       

        static double doubleFromFixed(int nFixed)
        {
                return nFixed/(double)(1 << PBITS);
        }

        static int fixedFromInt(int nV)
        {
                if(CHECK)
                        checkInt(nV);
                return nV<<PBITS;
        }

        static int fixedFromFloat(float nV)
        {
                if(CHECK)
                        checkFloat(nV);
                return (int)(nV *  (float)(1 << PBITS) + 0.5f);
        }

        static int fixedFromDouble(double nV)
        {
                if(CHECK)
                        checkDouble(nV);
                return (int)(nV * (double)(1 << PBITS) + 0.5f);
        }

        static int inverse(int nFixed)
        {
                return (__int32)(((__int64)1<<(2*PBITS))/nFixed);
        }

        static int multiply(int nLeftFixed, int nRightFixed)
        {
                return (__int32)(((__int64)nLeftFixed * (__int64)nRightFixed) >> PBITS);
        }

        static int divide(int nLeftFixed, int nRightFixed)
        {
                return (__int32)(((__int64)nLeftFixed << PBITS) / nRightFixed);
        }

        static int cos(int nFixed)
        {
                return fixedFromDouble(::cos(floatFromFixed(nFixed)));
        }

        static int sin(int nFixed)
        {
                return fixedFromDouble(::sin(floatFromFixed(nFixed)));
        }

        static int fabs(int nFixed)
        {
                return nFixed<0 ? -nFixed : nFixed;
        }

        static int sqrt(int nFixed)
        {
                return fixedFromDouble(::sqrt(floatFromFixed(nFixed)));
        }

        static int inverseSqrt(int nFixed)
        {
                return inverse(sqrt(nFixed));
        }

        static int ceil(int nFixed)
        {
                int ret = (nFixed>>PBITS)<<PBITS;

                if(nFixed>=0 && ret<nFixed)
                        ret += fixedFromInt(1);

                return ret;
        }

};


#endif //__ARTKPFIXEDBASE_GENERIC_HEADERFILE__