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GRect.cpp

//C-  -*- C++ -*-
//C- -------------------------------------------------------------------
//C- DjVuLibre-3.5
//C- Copyright (c) 2002  Leon Bottou and Yann Le Cun.
//C- Copyright (c) 2001  AT&T
//C-
//C- This software is subject to, and may be distributed under, the
//C- GNU General Public License, either Version 2 of the license,
//C- or (at your option) any later version. The license should have
//C- accompanied the software or you may obtain a copy of the license
//C- from the Free Software Foundation at http://www.fsf.org .
//C-
//C- This program is distributed in the hope that it will be useful,
//C- but WITHOUT ANY WARRANTY; without even the implied warranty of
//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//C- GNU General Public License for more details.
//C- 
//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library from
//C- Lizardtech Software.  Lizardtech Software has authorized us to
//C- replace the original DjVu(r) Reference Library notice by the following
//C- text (see doc/lizard2002.djvu and doc/lizardtech2007.djvu):
//C-
//C-  ------------------------------------------------------------------
//C- | DjVu (r) Reference Library (v. 3.5)
//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.
//C- | The DjVu Reference Library is protected by U.S. Pat. No.
//C- | 6,058,214 and patents pending.
//C- |
//C- | This software is subject to, and may be distributed under, the
//C- | GNU General Public License, either Version 2 of the license,
//C- | or (at your option) any later version. The license should have
//C- | accompanied the software or you may obtain a copy of the license
//C- | from the Free Software Foundation at http://www.fsf.org .
//C- |
//C- | The computer code originally released by LizardTech under this
//C- | license and unmodified by other parties is deemed "the LIZARDTECH
//C- | ORIGINAL CODE."  Subject to any third party intellectual property
//C- | claims, LizardTech grants recipient a worldwide, royalty-free, 
//C- | non-exclusive license to make, use, sell, or otherwise dispose of 
//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the 
//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU 
//C- | General Public License.   This grant only confers the right to 
//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to 
//C- | the extent such infringement is reasonably necessary to enable 
//C- | recipient to make, have made, practice, sell, or otherwise dispose 
//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to 
//C- | any greater extent that may be necessary to utilize further 
//C- | modifications or combinations.
//C- |
//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY
//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF
//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
//C- +------------------------------------------------------------------
// 
// $Id: GRect.cpp,v 1.12 2007/03/25 20:48:32 leonb Exp $
// $Name: debian_version_3_5_19-2 $

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if NEED_GNUG_PRAGMAS
# pragma implementation
#endif

// -- Implementation of class GRect and GRectMapper
// - Author: Leon Bottou, 05/1997


#include "GRect.h"
#include "GException.h"


#ifdef HAVE_NAMESPACES
namespace DJVU {
# ifdef NOT_DEFINED // Just to fool emacs c++ mode
}
#endif
#endif

// -- Local utilities

static inline int 
imin(int x, int y)
{
  if (x < y) 
    return x;
  else
    return y;
}

static inline int 
imax(int x, int y)
{
  if (x > y) 
    return x;
  else
    return y;
}

static inline void
iswap(int &x, int &y)
{
  int tmp = x; x = y; y = tmp;
}

// -- Class GRect

int 
00110 operator==(const GRect & r1, const GRect & r2)
{
  bool isempty1 = r1.isempty();
  bool isempty2 = r2.isempty();
  if (isempty1 || isempty2)
    if (isempty1 && isempty2)
      return 1;
  if ( r1.xmin==r2.xmin && r1.xmax==r2.xmax 
       && r1.ymin==r2.ymin && r1.ymax==r2.ymax )
    return 1;
  return 0;
}

int 
00124 GRect::inflate(int dx, int dy)
{
  xmin -= dx;
  xmax += dx;
  ymin -= dy;
  ymax += dy;
  if (! isempty()) 
    return 1;
  xmin = ymin = xmax = ymax = 0;
  return 0;
}

int 
00137 GRect::translate(int dx, int dy)
{
  xmin += dx;
  xmax += dx;
  ymin += dy;
  ymax += dy;
  if (! isempty()) 
    return 1;
  xmin = ymin = xmax = ymax = 0;
  return 0;
}

int  
00150 GRect::intersect(const GRect &rect1, const GRect &rect2)
{
  xmin = imax(rect1.xmin, rect2.xmin);
  xmax = imin(rect1.xmax, rect2.xmax);
  ymin = imax(rect1.ymin, rect2.ymin);
  ymax = imin(rect1.ymax, rect2.ymax);
  if (! isempty()) 
    return 1;
  xmin = ymin = xmax = ymax = 0;
  return 0;
}

int  
00163 GRect::recthull(const GRect &rect1, const GRect &rect2)
{
  if (rect1.isempty())
    {
      xmin = rect2.xmin;
      xmax = rect2.xmax;
      ymin = rect2.ymin;
      ymax = rect2.ymax;
      return !isempty();
    }
  if (rect2.isempty())
    {
      xmin = rect1.xmin;
      xmax = rect1.xmax;
      ymin = rect1.ymin;
      ymax = rect1.ymax;
      return !isempty();
    }
  xmin = imin(rect1.xmin, rect2.xmin);
  xmax = imax(rect1.xmax, rect2.xmax);
  ymin = imin(rect1.ymin, rect2.ymin);
  ymax = imax(rect1.ymax, rect2.ymax);
  return 1;
}

int
00189 GRect::contains(const GRect & rect) const
{
   GRect tmp_rect;
   tmp_rect.intersect(*this, rect);
   return tmp_rect==rect;
}

void
00197 GRect::scale(float factor)
{
      xmin = (int)(((float)xmin) * factor);
      ymin = (int)(((float)ymin) * factor);
      xmax = (int)(((float)xmax) * factor);
      ymax = (int)(((float)ymax) * factor);
}

void
00206 GRect::scale(float xfactor, float yfactor)
{
      xmin = (int)(((float)xmin) * xfactor);
      ymin = (int)(((float)ymin) * yfactor);
      xmax = (int)(((float)xmax) * xfactor);
      ymax = (int)(((float)ymax) * yfactor);
}
// -- Class GRatio


inline
GRectMapper::GRatio::GRatio()
  : p(0), q(1)
{
}

inline
GRectMapper::GRatio::GRatio(int p, int q)
  : p(p), q(q)
{
  if (q == 0) 
    G_THROW( ERR_MSG("GRect.div_zero") );
  if (p == 0)
    q = 1;
  if (q < 0)
    {
      p = -p; 
      q = -q; 
    }
  int gcd = 1;
  int g1 = p; 
  int g2 = q; 
  if (g1 > g2)
    {
      gcd = g1;
      g1 = g2;
      g2 = gcd;
    }
  while (g1 > 0)
    {
      gcd = g1;
      g1 = g2 % g1;
      g2 = gcd;
    }
  p /= gcd;
  q /= gcd;
}


#ifdef HAVE_LONG_LONG_INT
#define llint_t long long int
#else
#define llint_t long int
#endif

inline int 
operator*(int n, GRectMapper::GRatio r )
{ 
  /* [LB] -- This computation is carried out with integers and
     rational numbers because it must be exact.  Some lizard changed
     it to double and this is wrong.  I suspect they did so because
     they encountered overflow issues.  Let's use long long ints. */
  llint_t x = (llint_t) n * (llint_t) r.p;
  if (x >= 0)
    return   ((r.q/2 + x) / r.q);
  else
    return - ((r.q/2 - x) / r.q);
}

inline int 
operator/(int n, GRectMapper::GRatio r )
{ 
  /* [LB] -- See comment in operator*() above. */
  llint_t x = (llint_t) n * (llint_t) r.q;
  if (x >= 0)
    return   ((r.p/2 + x) / r.p);
  else
    return - ((r.p/2 - x) / r.p);
}


// -- Class GRectMapper

#define MIRRORX  1
#define MIRRORY  2
#define SWAPXY 4


00294 GRectMapper::GRectMapper()
: rectFrom(0,0,1,1), 
  rectTo(0,0,1,1),
  code(0)
{

}

void
00303 GRectMapper::clear()
{
  rectFrom = GRect(0,0,1,1);
  rectTo = GRect(0,0,1,1);
  code = 0;
}

void 
00311 GRectMapper::set_input(const GRect &rect)
{
  if (rect.isempty())
    G_THROW( ERR_MSG("GRect.empty_rect1") );
  rectFrom = rect;
  if (code & SWAPXY)
  {
    iswap(rectFrom.xmin, rectFrom.ymin);
    iswap(rectFrom.xmax, rectFrom.ymax);
  }
  rw = rh = GRatio();
}

void 
00325 GRectMapper::set_output(const GRect &rect)
{
  if (rect.isempty())
    G_THROW( ERR_MSG("GRect.empty_rect2") );
  rectTo = rect;
  rw = rh = GRatio();
}

void 
00334 GRectMapper::rotate(int count)
{
  int oldcode = code;
  switch (count & 0x3)
    {
    case 1:
      code ^= (code & SWAPXY) ? MIRRORY : MIRRORX;
      code ^= SWAPXY;
      break;
    case 2:
      code ^= (MIRRORX|MIRRORY);
      break;
    case 3:
      code ^= (code & SWAPXY) ? MIRRORX : MIRRORY;
      code ^= SWAPXY;
      break;
    }
  if ((oldcode ^ code) & SWAPXY)
    { 
      iswap(rectFrom.xmin, rectFrom.ymin);
      iswap(rectFrom.xmax, rectFrom.ymax);
      rw = rh = GRatio();
    }
}

void 
00360 GRectMapper::mirrorx()
{
  code ^= MIRRORX;
}

void 
00366 GRectMapper::mirrory()
{
  code ^= MIRRORY;
}

void
GRectMapper::precalc()
{
  if (rectTo.isempty() || rectFrom.isempty())
    G_THROW( ERR_MSG("GRect.empty_rect3") );
  rw = GRatio(rectTo.width(), rectFrom.width());
  rh = GRatio(rectTo.height(), rectFrom.height());
}

void 
00381 GRectMapper::map(int &x, int &y)
{
  int mx = x;
  int my = y;
  // precalc
  if (! (rw.p && rh.p))
    precalc();
  // swap and mirror
  if (code & SWAPXY)
    iswap(mx,my);
  if (code & MIRRORX)
    mx = rectFrom.xmin + rectFrom.xmax - mx;
  if (code & MIRRORY)
    my = rectFrom.ymin + rectFrom.ymax - my;
  // scale and translate
  x = rectTo.xmin + (mx - rectFrom.xmin) * rw;
  y = rectTo.ymin + (my - rectFrom.ymin) * rh;
}

void 
00401 GRectMapper::unmap(int &x, int &y)
{
  // precalc 
  if (! (rw.p && rh.p))
    precalc();
  // scale and translate
  int mx = rectFrom.xmin + (x - rectTo.xmin) / rw;
  int my = rectFrom.ymin + (y - rectTo.ymin) / rh;
  //  mirror and swap
  if (code & MIRRORX)
    mx = rectFrom.xmin + rectFrom.xmax - mx;
  if (code & MIRRORY)
    my = rectFrom.ymin + rectFrom.ymax - my;
  if (code & SWAPXY)
    iswap(mx,my);
  x = mx;
  y = my;
}

void 
00421 GRectMapper::map(GRect &rect)
{
  map(rect.xmin, rect.ymin);
  map(rect.xmax, rect.ymax);
  if (rect.xmin >= rect.xmax)
    iswap(rect.xmin, rect.xmax);
  if (rect.ymin >= rect.ymax)
    iswap(rect.ymin, rect.ymax);
}

void 
00432 GRectMapper::unmap(GRect &rect)
{
  unmap(rect.xmin, rect.ymin);
  unmap(rect.xmax, rect.ymax);
  if (rect.xmin >= rect.xmax)
    iswap(rect.xmin, rect.xmax);
  if (rect.ymin >= rect.ymax)
    iswap(rect.ymin, rect.ymax);
}

GRect 
00443 GRectMapper::get_input()
{
    return rectFrom;
}

GRect 
00449 GRectMapper::get_output()
{
    return rectTo;
}


#ifdef HAVE_NAMESPACES
}
# ifndef NOT_USING_DJVU_NAMESPACE
using namespace DJVU;
# endif
#endif

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