xref: /dports/lang/swi-pl/swipl-8.2.3/packages/xpce/src/adt/area.c

/*  Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    Copyright (c)  1985-2002, University of Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

#include <h/kernel.h>

/* FN will include the following names from this comment.  Donot remove
   it!

NAME_northWest
NAME_southWest
NAME_northEast
NAME_southEast
*/

#define InitAreaA	int ax = valInt(a->x), ay = valInt(a->y),	\
			    aw = valInt(a->w), ah = valInt(a->h)

#define InitAreaB	int bx = valInt(b->x), by = valInt(b->y),	\
			    bw = valInt(b->w), bh = valInt(b->h)

#define ExitAreaA	assign(a, x, toInt(ax));			\
		        assign(a, y, toInt(ay));			\
		        assign(a, w, toInt(aw));			\
		        assign(a, h, toInt(ah));

static status normaliseArea(Area a);
static status inArea(Area a, Int x, Int y);

static status
initialiseArea(Area a, Int x, Int y, Int w, Int h)
{ assign(a, x, isDefault(x) ? ZERO : x);
  assign(a, y, isDefault(y) ? ZERO : y);
  assign(a, w, isDefault(w) ? ZERO : w);
  assign(a, h, isDefault(h) ? ZERO : h);

  succeed;
}


static status
equalArea(Area a, Area b)
{ InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  if (ax == bx && ay == by && aw == bw && ah == bh)
    succeed;
  fail;
}


status
intersectionArea(Area a, Area b)
{ int x, y, w, h;
  Name orientation;

  InitAreaA;
  InitAreaB;

  orientation = OrientationArea(aw, ah);

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  x = (ax > bx ? ax : bx);
  y = (ay > by ? ay : by);
  w = (ax + aw < bx + bw ? ax + aw : bx + bw) - x;
  h = (ay + ah < by + bh ? ay + ah : by + bh) - y;

  if (w < 0 || h < 0)
    fail;

  OrientateArea(x, y, w, h, orientation);

  assign(a, x, toInt(x));
  assign(a, y, toInt(y));
  assign(a, w, toInt(w));
  assign(a, h, toInt(h));

  succeed;
}


static Area
getIntersectionArea(Area a, Area b)
{ Area c;

  c = answerObject(ClassArea, a->x, a->y, a->w, a->h, EAV);
  if ( intersectionArea(c, b) )
    answer(c);

  freeObject(c);
  fail;
}


static status
unionArea(Area a, Area b)
{ int x, y, w, h;
  Name orientation;

  if ( b->w == ZERO && b->h == ZERO )
    succeed;
  if ( a->w == ZERO && a->h == ZERO )
  { copyArea(a, b);
    return normaliseArea(a);
  }

  { InitAreaA;
    InitAreaB;

    orientation = OrientationArea(aw, ah);

    NormaliseArea(ax, ay, aw, ah);
    NormaliseArea(bx, by, bw, bh);

    x = (ax < bx ? ax : bx);
    y = (ay < by ? ay : by);
    w = (ax + aw > bx + bw ? ax + aw : bx + bw) - x;
    h = (ay + ah > by + bh ? ay + ah : by + bh) - y;

    OrientateArea(x, y, w, h, orientation);

    assign(a, x, toInt(x));
    assign(a, y, toInt(y));
    assign(a, w, toInt(w));
    assign(a, h, toInt(h));
  }

  succeed;
}


status
unionNormalisedArea(Area a, Area b)
{ int x, y, w, h;

  if ( b->w == ZERO && b->h == ZERO )
    succeed;
  if ( a->w == ZERO && a->h == ZERO )
  { copyArea(a, b);
    return normaliseArea(a);
  }

  { InitAreaA;
    InitAreaB;

    NormaliseArea(bx, by, bw, bh);

    x = (ax < bx ? ax : bx);
    y = (ay < by ? ay : by);
    w = (ax + aw > bx + bw ? ax + aw : bx + bw) - x;
    h = (ay + ah > by + bh ? ay + ah : by + bh) - y;

    assign(a, x, toInt(x));
    assign(a, y, toInt(y));
    assign(a, w, toInt(w));
    assign(a, h, toInt(h));
  }

  succeed;
}


static Area
getUnionArea(Area a, Area b)
{ Area c;

  c = answerObject(ClassArea, a->x, a->y, a->w, a->h, EAV);
  unionArea(c, b);
  answer(c);
}


status
sizeArea(Area a, Size s)
{ assign(a, w, s->w);
  assign(a, h, s->h);

  succeed;
}


Size
getSizeArea(Area a)
{ answer(answerObject(ClassSize, a->w, a->h, EAV));
}


static Int
getMeasureArea(Area a)
{ int w = valInt(a->w);
  int h = valInt(a->h);

  answer(toInt(abs(w) * abs(h)));
}


status
pointInArea(Area a, Point p)
{ return inArea(a, p->x, p->y);
}


status
overlapArea(Area a, Area b)
{ InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  if (by >= ay+ah || by+bh <= ay || bx >= ax+aw || bx+bw <= ax)
    fail;
  succeed;
}


status
relativeMoveArea(Area a, Point p)
{ assign(a,x, add(a->x, p->x));
  assign(a,y, add(a->y, p->y));

  succeed;
}


status
relativeMoveBackArea(Area a, Point p)
{ assign(a,x, sub(a->x, p->x));
  assign(a,y, sub(a->y, p->y));

  succeed;
}


static status
positionArea(Area a, Point p)
{ assign(a, x, p->x);
  assign(a, y, p->y);

  succeed;
}


Point
getPositionArea(Area a)
{ answer(answerObject(ClassPoint, a->x, a->y, EAV));
}


static status
inArea(Area a, Int x, Int y)
{ InitAreaA;

  NormaliseArea(ax, ay, aw, ah);

  if (valInt(x) >= ax && valInt(x) <= ax+aw
   && valInt(y) >= ay && valInt(y) <= ay+ah)
    succeed;
  fail;
}


status
copyArea(Area a, Area b)
{ assign(a, x, b->x);
  assign(a, y, b->y);
  assign(a, w, b->w);
  assign(a, h, b->h);

  succeed;
}


Area
getCopyArea(Area a)
{ answer(answerObject(classOfObject(a), a->x, a->y, a->w, a->h, EAV));
}


status
insideArea(Area a, Area b)
{ InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  if (bx < ax)		fail;
  if (bx+bw > ax+aw-1)	fail;
  if (by < ay)		fail;
  if (by+bh > ay+ah-1)	fail;

  succeed;
}


Int
getDistanceXArea(Area a, Area b)
{ int ax = valInt(a->x), aw = valInt(a->w);
  int bx = valInt(b->x), bw = valInt(b->w);

  if ( aw < 0 ) ax += aw, aw = -aw;
  if ( bw < 0 ) bx += bw, bw = -bw;

  if ( ax + aw < bx ) answer(toInt(bx-(ax+aw)));
  if ( bx + bw < ax ) answer(toInt(ax-(bx+bw)));

  answer(ZERO);
}


Int
getDistanceYArea(Area a, Area b)
{ int ay = valInt(a->y), ah = valInt(a->h);
  int by = valInt(b->y), bh = valInt(b->h);

  if ( ah < 0 ) ay += ah, ah = -ah;
  if ( bh < 0 ) by += bh, bh = -bh;

  if ( ay + ah < by ) answer(toInt(by-(ay+ah)));
  if ( by + bh < ay ) answer(toInt(ay-(by+bh)));

  answer(ZERO);
}


Int
getDistanceArea(Area a, Area b)
{ InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  if (overlapArea(a, b) == SUCCEED)
    answer(ZERO);

  if (ay+ah < by)
  { if (bx+bw < ax)
      answer(toInt(distance(bx+bw, by, ax, ay+ah)));
    if (bx > ax+aw)
      answer(toInt(distance(ax+aw, ay+ah, bx, by)));
    answer(toInt(by-(ay+ah)));
  }

  if (by+bh < ay)
  { if (ax+aw < bx)
      answer(toInt(distance(ax+aw, ay, bx, by+bh)));
    if (bx+bw < ax)
      answer(toInt(distance(bx+bw, by+bh, ax, ay)));
    answer(toInt(ay-(by+bh)));
  }

  if (ax+aw < bx)
    answer(toInt(bx-(ax+aw)));

  answer(toInt(ax-(bx+bw)));
}


status
clearArea(Area a)
{ assign(a, x, ZERO);
  assign(a, y, ZERO);
  assign(a, w, ZERO);
  assign(a, h, ZERO);

  succeed;
}


static status
centerArea(Area a, Point pos)
{ assign(a, x, dif(pos->x,a->w));
  assign(a, y, dif(pos->y,a->h));

  succeed;
}


static Int
getLeftSideArea(Area a)
{ if ( valInt(a->w) >= 0 )
    answer(a->x);
  else
    answer(add(a->x, a->w));
}


static Int
getRightSideArea(Area a)
{ if ( valInt(a->w) >= 0 )
    answer(add(a->x, a->w));
  else
    answer(a->x);
}


static Int
getTopSideArea(Area a)
{ if ( valInt(a->h) >= 0 )
    answer(a->y);
  else
    answer(add(a->y, a->h));
}


static Int
getBottomSideArea(Area a)
{ if ( valInt(a->h) >= 0 )
    answer(add(a->y, a->h));
  else
    answer(a->y);
}


static Point
getCenterArea(Area a)
{ answer(answerObject(ClassPoint, mid(a->x,a->w), mid(a->y,a->h), EAV));
}


static status
cornerArea(Area a, Point pos)
{ int w, h;

  w = valInt(pos->x) - valInt(a->x);
  w += (w>=0 ? 1 : -1);
  h = valInt(pos->y) - valInt(a->y);
  h += (h>=0 ? 1 : -1);

  assign(a, w, toInt(w));
  assign(a, h, toInt(h));

  succeed;
}


static Point
getCornerArea(Area a)
{ answer(answerObject(ClassPoint, add(a->x,a->w), add(a->y,a->h), EAV));
}


status
setArea(Area a, Int x, Int y, Int w, Int h)
{ if (notDefault(x)) assign(a, x, x);
  if (notDefault(y)) assign(a, y, y);
  if (notDefault(w)) assign(a, w, w);
  if (notDefault(h)) assign(a, h, h);

  succeed;
}


status
increaseArea(Area a, Int i)
{ int d = valInt(i);
  InitAreaA;

  if (aw >= 0)
    aw += 2*d, ax -= d;
  else
    aw -= 2*d, ax += d;

  if (ah >= 0)
    ah += 2*d, ay -= d;
  else
    ah -= 2*d, ay += d;

  ExitAreaA;

  succeed;
}


static status
decreaseArea(Area a, Int i)
{ return increaseArea(a, toInt(-valInt(i)));
}


static status
normaliseArea(Area a)
{ if ( valInt(a->w) < 0 || valInt(a->h) < 0 )
  { InitAreaA;
    NormaliseArea(ax, ay, aw, ah);
    ExitAreaA;
  }

  succeed;
}


static Area
getNormalisedArea(Area a)
{ InitAreaA;
  NormaliseArea(ax, ay, aw, ah);

  answer(answerObject(ClassArea,
		      toInt(ax), toInt(ay), toInt(aw), toInt(ah), EAV));
}


status
orientationArea(Area a, Name orientation)
{ InitAreaA;
  OrientateArea(ax, ay, aw, ah, orientation);
  ExitAreaA;

  succeed;
}


Name
getOrientationArea(Area a)
{ Name orientation;
  int aw = valInt(a->w);
  int ah = valInt(a->h);

  orientation = OrientationArea(aw, ah);

  answer(orientation);
}


#undef NEAR
#undef SAME
#undef LESS
#define NEAR(a, b, d, m, p)	{ if (abs(a-b) <= d) m |= p; }
#define SAME(a, b, m, p)	{ if (a == b) m |= p; }
#define LESS(a, b, m, p)	{ if (a < b) m |= p; }

static Int
getNearSidesArea(Area a, Area b, Int distance)
{ int d=valInt(distance);
  int a_top, a_center, a_bottom, a_left, a_middle, a_right;
  int b_top, b_center, b_bottom, b_left, b_middle, b_right;
  register unsigned long mask;

  InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  a_top = ay;
  a_bottom = ay+ah-1;
  a_center = (a_top+a_bottom+1)/2;

  a_left = ax;
  a_right = ax+aw-1;
  a_middle = (a_left+a_right+1)/2;

  b_top = by;
  b_bottom = by+bh-1;
  b_center = (b_top+b_bottom+1)/2;

  b_left = bx;
  b_right = bx+bw-1;
  b_middle = (b_left+b_right+1)/2;

  mask = 0;

  NEAR(a_top,    b_top,    d, mask, 01);
  NEAR(a_top,    b_center, d, mask, 02);
  NEAR(a_top,    b_bottom, d, mask, 04);
  NEAR(a_center, b_top,    d, mask, 010);
  NEAR(a_center, b_center, d, mask, 020);
  NEAR(a_center, b_bottom, d, mask, 040);
  NEAR(a_bottom, b_top,    d, mask, 0100);
  NEAR(a_bottom, b_center, d, mask, 0200);
  NEAR(a_bottom, b_bottom, d, mask, 0400);

  NEAR(a_left,   b_left,   d, mask, 01000);
  NEAR(a_left,   b_middle, d, mask, 02000);
  NEAR(a_left,   b_right,  d, mask, 04000);
  NEAR(a_middle, b_left,   d, mask, 010000);
  NEAR(a_middle, b_middle, d, mask, 020000);
  NEAR(a_middle, b_right,  d, mask, 040000);
  NEAR(a_right,  b_left,   d, mask, 0100000);
  NEAR(a_right,  b_middle, d, mask, 0200000);
  NEAR(a_right,  b_right,  d, mask, 0400000);

  answer(toInt(mask));
}


static Int
sameSidesArea(Area a, Area b)
{ int a_top, a_center, a_bottom, a_left, a_middle, a_right;
  int b_top, b_center, b_bottom, b_left, b_middle, b_right;
  register unsigned long mask;

  InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  a_top = ay;
  a_bottom = ay+ah-1;
  a_center = (a_top+a_bottom+1)/2;

  a_left = ax;
  a_right = ax+aw-1;
  a_middle = (a_left+a_right+1)/2;

  b_top = by;
  b_bottom = by+bh-1;
  b_center = (b_top+b_bottom+1)/2;

  b_left = bx;
  b_right = bx+bw-1;
  b_middle = (b_left+b_right+1)/2;

  mask = 0;

  SAME(a_top,    b_top,    mask, 01);
  SAME(a_top,    b_center, mask, 02);
  SAME(a_top,    b_bottom, mask, 04);
  SAME(a_center, b_top,    mask, 010);
  SAME(a_center, b_center, mask, 020);
  SAME(a_center, b_bottom, mask, 040);
  SAME(a_bottom, b_top,    mask, 0100);
  SAME(a_bottom, b_center, mask, 0200);
  SAME(a_bottom, b_bottom, mask, 0400);

  SAME(a_left,   b_left,   mask, 01000);
  SAME(a_left,   b_middle, mask, 02000);
  SAME(a_left,   b_right,  mask, 04000);
  SAME(a_middle, b_left,   mask, 010000);
  SAME(a_middle, b_middle, mask, 020000);
  SAME(a_middle, b_right,  mask, 040000);
  SAME(a_right,  b_left,   mask, 0100000);
  SAME(a_right,  b_middle, mask, 0200000);
  SAME(a_right,  b_right,  mask, 0400000);

  answer(toInt(mask));
}


static Int
getLessSidesArea(Area a, Area b)
{ int a_top, a_center, a_bottom, a_left, a_middle, a_right;
  int b_top, b_center, b_bottom, b_left, b_middle, b_right;
  register unsigned long mask;

  InitAreaA;
  InitAreaB;

  NormaliseArea(ax, ay, aw, ah);
  NormaliseArea(bx, by, bw, bh);

  a_top = ay;
  a_bottom = ay+ah-1;
  a_center = (a_top+a_bottom+1)/2;

  a_left = ax;
  a_right = ax+aw-1;
  a_middle = (a_left+a_right+1)/2;

  b_top = by;
  b_bottom = by+bh-1;
  b_center = (b_top+b_bottom+1)/2;

  b_left = bx;
  b_right = bx+bw-1;
  b_middle = (b_left+b_right+1)/2;

  mask = 0;

  LESS(a_top,    b_top,    mask, 01);
  LESS(a_top,    b_center, mask, 02);
  LESS(a_top,    b_bottom, mask, 04);
  LESS(a_center, b_top,    mask, 010);
  LESS(a_center, b_center, mask, 020);
  LESS(a_center, b_bottom, mask, 040);
  LESS(a_bottom, b_top,    mask, 0100);
  LESS(a_bottom, b_center, mask, 0200);
  LESS(a_bottom, b_bottom, mask, 0400);

  LESS(a_left,   b_left,   mask, 01000);
  LESS(a_left,   b_middle, mask, 02000);
  LESS(a_left,   b_right,  mask, 04000);
  LESS(a_middle, b_left,   mask, 010000);
  LESS(a_middle, b_middle, mask, 020000);
  LESS(a_middle, b_right,  mask, 040000);
  LESS(a_right,  b_left,   mask, 0100000);
  LESS(a_right,  b_middle, mask, 0200000);
  LESS(a_right,  b_right,  mask, 0400000);

  answer(toInt(mask));
}


		 /*******************************
		 *	 CLASS DECLARATION	*
		 *******************************/

/* Type declaractions */

static char *T_nearSides[] =
        { "area", "int" };
static char *T_dxdydwdh[] =
        { "x=[int]", "y=[int]", "width=[int]", "height=[int]" };

/* Instance Variables */

static vardecl var_area[] =
{ IV(NAME_x, "int", IV_BOTH,
     NAME_position, "Origin's X-value"),
  IV(NAME_y, "int", IV_BOTH,
     NAME_position, "Origin's Y-value"),
  IV(NAME_width, "int", IV_BOTH,
     NAME_dimension, "Width in pixels (may be negative)"),
  IV(NAME_height, "int", IV_BOTH,
     NAME_dimension, "Height in pixels (may be negative)")
};

/* Send Methods */

static senddecl send_area[] =
{ SM(NAME_initialise, 4, T_dxdydwdh, initialiseArea,
     DEFAULT, "Create area from X, Y, W and H"),
  SM(NAME_copy, 1, "area", copyArea,
     NAME_copy, "Copy X, Y, W and H from argument area"),
  SM(NAME_equal, 1, "area", equalArea,
     NAME_equality, "Test if area is equal to the argument"),
  SM(NAME_normalise, 0, NULL, normaliseArea,
     NAME_orientation, "Make top-left corner the origin"),
  SM(NAME_orientation, 1, "{north_west,south_west,north_east,south_east}",
     orientationArea,
     NAME_orientation, "Put origin at indicated corner"),
  SM(NAME_center, 1, "point", centerArea,
     NAME_position, "Move to make point the center"),
  SM(NAME_position, 1, "point", positionArea,
     NAME_position, "Move origin to point"),
  SM(NAME_relativeMove, 1, "point", relativeMoveArea,
     NAME_position, "Move origin relative by point"),
  SM(NAME_in, 1, "point", pointInArea,
     NAME_relation, "Test if point is in area"),
  SM(NAME_inside, 1, "area", insideArea,
     NAME_relation, "Test if argument is entirely in area"),
  SM(NAME_intersection, 1, "area", intersectionArea,
     NAME_relation, "Make area the intersection with argument"),
  SM(NAME_overlap, 1, "area", overlapArea,
     NAME_relation, "Test whether area overlaps argument"),
  SM(NAME_clear, 0, NULL, clearArea,
     NAME_resize, "Set X, Y, W and H to 0"),
  SM(NAME_corner, 1, "point", cornerArea,
     NAME_resize, "Resize to make opposite of origin point"),
  SM(NAME_decrease, 1, "int", decreaseArea,
     NAME_resize, "Move all sides inwards"),
  SM(NAME_increase, 1, "int", increaseArea,
     NAME_resize, "Move all sides outwards"),
  SM(NAME_set, 4, T_dxdydwdh, setArea,
     NAME_resize, "Set X, Y, W and H values"),
  SM(NAME_size, 1, "size", sizeArea,
     NAME_resize, "Resize area to size"),
  SM(NAME_union, 1, "area", unionArea,
     NAME_resize, "Enlarge area to entail argument")
};

/* Get Methods */

static getdecl get_area[] =
{ GM(NAME_normalised, 0, "area", NULL, getNormalisedArea,
     NAME_copy, "New area with origin at top-left"),
  GM(NAME_measure, 0, "int", NULL, getMeasureArea,
     NAME_dimension, "`Area' of the area"),
  GM(NAME_size, 0, "size", NULL, getSizeArea,
     NAME_dimension, "New size from size of area"),
  GM(NAME_orientation, 0, "{north_west,south_west,north_east,south_east}", NULL, getOrientationArea,
     NAME_orientation, "Current orientation"),
  GM(NAME_center, 0, "point", NULL, getCenterArea,
     NAME_position, "New point from center position"),
  GM(NAME_corner, 0, "point", NULL, getCornerArea,
     NAME_position, "New point from point opposite origin"),
  GM(NAME_position, 0, "point", NULL, getPositionArea,
     NAME_position, "New point from origin"),
  GM(NAME_distance, 1, "int", "area", getDistanceArea,
     NAME_relation, "Closest distance between areas"),
  GM(NAME_distanceX, 1, "int", "area", getDistanceXArea,
     NAME_relation, "Distance between area's in X-direction"),
  GM(NAME_distanceY, 1, "int", "area", getDistanceYArea,
     NAME_relation, "Distance between area's in Y-direction"),
  GM(NAME_intersection, 1, "area", "area", getIntersectionArea,
     NAME_relation, "New area from intersection"),
  GM(NAME_lessSides, 1, "int", "area", getLessSidesArea,
     NAME_relation, "Bitmask (int) of sides closer to origin"),
  GM(NAME_nearSides, 2, "int", T_nearSides, getNearSidesArea,
     NAME_relation, "Bitmask (int) of almost equal sides"),
  GM(NAME_sameSides, 1, "int", "area", sameSidesArea,
     NAME_relation, "Bitmask (int) of equal sides"),
  GM(NAME_union, 1, "area", "area", getUnionArea,
     NAME_resize, "New area from union"),
  GM(NAME_bottomSide, 0, "int", NULL, getBottomSideArea,
     NAME_side, "Bottom-side of area"),
  GM(NAME_leftSide, 0, "int", NULL, getLeftSideArea,
     NAME_side, "Left-side of area"),
  GM(NAME_rightSide, 0, "int", NULL, getRightSideArea,
     NAME_side, "Right-side of area"),
  GM(NAME_topSide, 0, "int", NULL, getTopSideArea,
     NAME_side, "Top-side of area")
};

/* Resources */

#define rc_area NULL
/*
static classvardecl rc_area[] =
{
};
*/

/* Class Declaration */

static Name area_termnames[] = { NAME_x, NAME_y, NAME_width, NAME_height };

ClassDecl(area_decls,
          var_area, send_area, get_area, rc_area,
          4, area_termnames,
          "$Rev$");


status
makeClassArea(Class class)
{ return declareClass(class, &area_decls);
}