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tdegraphics/kviewshell/plugins/djvu/libdjvu/GRect.h

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//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, Version 2. 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
//C- distributed by Lizardtech Software. On July 19th 2002, Lizardtech
//C- Software authorized us to replace the original DjVu(r) Reference
//C- Library notice by the following text (see doc/lizard2002.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, Version 2. 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.h,v 1.9 2003/11/07 22:08:21 leonb Exp $
// $Name: release_3_5_15 $
#ifndef _GRECT_H_
#define _GRECT_H_
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#if NEED_GNUG_PRAGMAS
# pragma interface
#endif
/** @name GRect.h
Files #"GRect.h"# and #"GRect.cpp"# implement basic operations on
rectangles. Class \Ref{GRect} is used to represent rectangles. Class
\Ref{GRectMapper} represent the correspondence between points relative to
given rectangles. Class \Ref{GRatio} is used to represent scaling factors
as rational numbers.
@memo
Rectangle manipulation class.
@author
L\'eon Bottou <leonb@research.att.com> -- initial implementation.
@version
#$Id: GRect.h,v 1.9 2003/11/07 22:08:21 leonb Exp $# */
//@{
#include "DjVuGlobal.h"
#ifdef HAVE_NAMESPACES
namespace DJVU {
# ifdef NOT_DEFINED // Just to fool emacs c++ mode
}
#endif
#endif
/** @name Point Coordinates vs. Pixel Coordinates
The DjVu technology relies on the accurate superposition of images at
different resolutions. Such an accuracy cannot be reached with the usual
assumption that pixels are small enough to be considered infinitesimally
small. We must distinguish very precisely ``points'' and ``pixels''.
This distinction is essential for performing scaling operations.
The pixels of an image are identified by ``pixel coordinates''. The
bottom-left corner pixel has coordinates #(0,0)# and the top-right corner
pixel has coordinates #(w-1,h-1)# where #w# and #h# are the image size.
Pixel coordinates are necessarily integers since pixels never overlap.
An infinitesimally small point is identified by its ``point coordinates''.
There may be fractional point coordinates, although this library does not
make use of them. Points with integer coordinates are located {\em on the
corners of each pixel}. They are not located on the pixel centers. The
center of the pixel with pixel coordinates #(i,j)# is located at point
coordinates #(i+1/2,j+1/2)#. In other words, the pixel #(i,j)# extends
from point #(i,j)# to point #(i+1,j+1)#.
Therefore, the point located on the bottom left corner of an image has
coordinates #(0,0)#. This point is in fact the bottom left corner of the
bottom left pixel of the image. The point located on the top right corner
of an image has coordinates #(w,h)# where #w# and #h# are the image size.
This is in fact the top right corner of pixel #(w-1,h-1)# which is the
image pixel with the highest coordinates.
*/
//@{
//@}
/** Rectangle class. Each instance of this class represents a rectangle whose
sides are parallel to the axis. Such a rectangle represents all the points
whose coordinates lies between well defined minimal and maximal values.
Member functions can combine several rectangles by computing the
intersection of rectangles (\Ref{intersect}) or the smallest rectangle
enclosing two rectangles (\Ref{recthull}). */
class GRect
{
public:
/** #OrientationBits# defines 3 mutually exclusive
bits to indicate the image orientation.
There are four possible rotation values for an image
which are 0 degrees, 90 degrees, 180 degrees, and 270 degrees.
In addition the image can be mirrored backwards in any of these
orientations, giving a possible of 8 orientations. To sanely deal
with these orientations, we have defined 3 mutually exclusive
bits. These are BOTTOM_UP, MIRROR, and ROTATE90_CW.
*/
enum OrientationBits
{
BOTTOM_UP=0x1, /* Upside down */
MIRROR=0x2, /* Written backwards. (right to left) */
ROTATE90_CW=0x4 /* rotated 90 degrees */
};
/** #Orientations# defines all 8 possible orientations, using
the three \Ref{OrientationBits}.
\begin{itemize}
\item {\em TDLRNR} for Top Down, Left to Right, No Rotation.
\item {\em BULRNR} for Bottom Up, Left to Right, No Rotation.
\item {\em TDRLNR} for Top Down, Right to Left, No Rotation.
\item {\em BURLNR} for Bottom Up, Right to Left, No Rotation.
\item {\em TDLRCW} for Top Down, Left to Right, 90 degree CW rotation.
\item {\em BULRCW} for Bottom Up, Left to Right, 90 degree CW rotation.
\item {\em TDRLCW} for Top Down, Right to Left, 90 degree CW rotation.
\item {\em BURLCW} for Bottom Up, Right to Left, 90 degree CW rotation.
\end{itemize}
*/
enum Orientations
{
TDLRNR=0, /* normal orientation */
BULRNR=BOTTOM_UP, /* upside down */
TDRLNR=MIRROR, /* backwards (right to left) */
BURLNR=MIRROR|BOTTOM_UP, /* rotate 180 */
TDLRCW=ROTATE90_CW, /* rotated 90 */
BULRCW=ROTATE90_CW|BOTTOM_UP, /* backwards and rotate 180 */
TDRLCW=ROTATE90_CW|MIRROR, /* backwards and rotate 90 */
BURLCW=ROTATE90_CW|MIRROR|BOTTOM_UP /* rotate 270 */
};
static Orientations
rotate(const int angle,Orientations orientation)
{
for(int a=(((angle)%360)+405)%360;a>90;a-=90)
orientation=(Orientations)((int)orientation^(int)(orientation&ROTATE90_CW)?BURLCW:TDLRCW);
return orientation;
}
static int
findangle(const Orientations orientation)
{
int a=270;
while(a&&(rotate(a,BURLNR)!=orientation)&&(rotate(a,TDRLNR)!=orientation))
a-=90;
return a;
}
/** Constructs an empty rectangle */
GRect();
/** Constructs a rectangle given its minimal coordinates #xmin# and #ymin#,
and its measurements #width# and #height#. Setting #width# or #height# to zero
produces an empty rectangle. */
GRect(int xmin, int ymin, unsigned int width=0, unsigned int height=0);
/** Returns the rectangle width. */
int width() const;
/** Returns the rectangle height. */
int height() const;
/** Returns the area of the rectangle. */
int area() const;
/** Returns true if the rectangle is empty. */
int isempty() const;
/** Returns true if the rectangle contains pixel (#x#,#y#). A rectangle
contains all pixels with horizontal pixel coordinates in range #xmin#
(inclusive) to #xmax# (exclusive) and vertical coordinates #ymin#
(inclusive) to #ymax# (exclusive). */
int contains(int x, int y) const;
/** Returns true if this rectangle contains the passed rectangle #rect#.
The function basically checks, that the intersection of this rectangle
with #rect# is #rect#. */
int contains(const GRect & rect) const;
/** Returns true if rectangles #r1# and #r2# are equal. */
friend int operator==(const GRect & r1, const GRect & r2);
/** Returns true if rectangles #r1# and #r2# are not equal. */
friend int operator!=(const GRect & r1, const GRect & r2);
/** Resets the rectangle to the empty rectangle */
void clear();
/** Fatten the rectangle. Both vertical sides of the rectangle are pushed
apart by #dx# units. Both horizontal sides of the rectangle are pushed
apart by #dy# units. Setting arguments #dx# (resp. #dy#) to a negative
value reduces the rectangle horizontal (resp. vertical) size. */
int inflate(int dx, int dy);
/** Translate the rectangle. The new rectangle is composed of all the points
of the old rectangle translated by #dx# units horizontally and #dy#
units vertically. */
int translate(int dx, int dy);
/** Sets the rectangle to the intersection of rectangles #rect1# and #rect2#.
This function returns true if the intersection rectangle is not empty. */
int intersect(const GRect &rect1, const GRect &rect2);
/** Sets the rectangle to the smallest rectangle containing the points of
both rectangles #rect1# and #rect2#. This function returns true if the
created rectangle is not empty. */
int recthull(const GRect &rect1, const GRect &rect2);
/** Multiplies xmin, ymin, xmax, ymax by factor and scales the rectangle*/
void scale(float factor);
/** Multiplies xmin, xmax by xfactor and ymin, ymax by yfactor and scales the rectangle*/
void scale(float xfactor, float yfactor);
/** Minimal horizontal point coordinate of the rectangle. */
int xmin;
/** Minimal vertical point coordinate of the rectangle. */
int ymin;
/** Maximal horizontal point coordinate of the rectangle. */
int xmax;
/** Maximal vertical point coordinate of the rectangle. */
int ymax;
};
/** Maps points from one rectangle to another rectangle. This class
represents a relation between the points of two rectangles. Given the
coordinates of a point in the first rectangle (input rectangle), function
\Ref{map} computes the coordinates of the corresponding point in the
second rectangle (the output rectangle). This function actually implements
an affine transform which maps the corners of the first rectangle onto the
matching corners of the second rectangle. The scaling operation is
performed using integer fraction arithmetic in order to maximize
accuracy. */
class GRectMapper
{
public:
/** Constructs a rectangle mapper. */
GRectMapper();
/** Resets the rectangle mapper state. Both the input rectangle
and the output rectangle are marked as undefined. */
void clear();
/** Sets the input rectangle. */
void set_input(const GRect &rect);
/** Returns the input rectangle. */
GRect get_input();
/** Sets the output rectangle. */
void set_output(const GRect &rect);
/** Returns the output rectangle. */
GRect get_output();
/** Composes the affine transform with a rotation of #count# quarter turns
counter-clockwise. This operation essentially is a modification of the
match between the corners of the input rectangle and the corners of the
output rectangle. */
void rotate(int count=1);
/** Composes the affine transform with a symmetry with respect to the
vertical line crossing the center of the output rectangle. This
operation essentially is a modification of the match between the corners
of the input rectangle and the corners of the output rectangle. */
void mirrorx();
/** Composes the affine transform with a symmetry with respect to the
horizontal line crossing the center of the output rectangle. This
operation essentially is a modification of the match between the corners
of the input rectangle and the corners of the output rectangle. */
void mirrory();
/** Maps a point according to the affine transform. Variables #x# and #y#
initially contain the coordinates of a point. This operation overwrites
these variables with the coordinates of a second point located in the
same position relative to the corners of the output rectangle as the
first point relative to the matching corners of the input rectangle.
Coordinates are rounded to the nearest integer. */
void map(int &x, int &y);
/** Maps a rectangle according to the affine transform. This operation
consists in mapping the rectangle corners and reordering the corners in
the canonical rectangle representation. Variable #rect# is overwritten
with the new rectangle coordinates. */
void map(GRect &rect);
/** Maps a point according to the inverse of the affine transform.
Variables #x# and #y# initially contain the coordinates of a point. This
operation overwrites these variables with the coordinates of a second
point located in the same position relative to the corners of input
rectangle as the first point relative to the matching corners of the
input rectangle. Coordinates are rounded to the nearest integer. */
void unmap(int &x, int &y);
/** Maps a rectangle according to the inverse of the affine transform. This
operation consists in mapping the rectangle corners and reordering the
corners in the canonical rectangle representation. Variable #rect# is
overwritten with the new rectangle coordinates. */
void unmap(GRect &rect);
private:
// GRatio
struct GRatio {
GRatio ();
GRatio (int p, int q);
int p;
int q;
};
// Data
GRect rectFrom;
GRect rectTo;
int code;
// Helper
void precalc();
friend int operator*(int n, GRatio r );
friend int operator/(int n, GRatio r );
GRatio rw;
GRatio rh;
};
//@}
// ---- INLINES
inline
GRect::GRect()
: xmin(0), ymin(0), xmax(0), ymax(0)
{
}
inline
GRect::GRect(int xmin, int ymin, unsigned int width, unsigned int height)
: xmin(xmin), ymin(ymin), xmax(xmin+width), ymax(ymin+height)
{
}
inline int
GRect::width() const
{
return xmax - xmin;
}
inline int
GRect::height() const
{
return ymax - ymin;
}
inline int
GRect::isempty() const
{
return (xmin>=xmax || ymin>=ymax);
}
inline int
GRect::area() const
{
return isempty() ? 0 : (xmax-xmin)*(ymax-ymin);
}
inline int
GRect::contains(int x, int y) const
{
return (x>=xmin && x<xmax && y>=ymin && y<ymax);
}
inline void
GRect::clear()
{
xmin = xmax = ymin = ymax = 0;
}
inline int
operator!=(const GRect & r1, const GRect & r2)
{
return !(r1==r2);
}
// ---- THE END
#ifdef HAVE_NAMESPACES
}
# ifndef NOT_USING_DJVU_NAMESPACE
using namespace DJVU;
# endif
#endif
#endif