/*  $Id: point.c,v 1.15 2005/01/03 10:17:40 jan Exp $

    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

    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.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <h/kernel.h>
#include <h/graphics.h>
#include <math.h>

static status
initialisePoint(Point p, Int x, Int y)
{ if ( isDefault(x) ) x = ZERO;
  if ( isDefault(y) ) y = ZERO;
  assign(p, x, x);
  assign(p, y, y);

  succeed;
}


static Point
getConvertPoint(Class class, Any obj)
{ if ( instanceOfObject(obj, ClassEvent) )
    return getPositionEvent((EventObj) obj, DEFAULT);
  else
  { CharArray ca = obj;
    int x, y;

    if ( isstrA(&ca->data) &&
	 sscanf((char *)ca->data.s_textA, "%d,%d", &x, &y) == 2 )
      answer(newObject(ClassPoint, toInt(x), toInt(y), EAV));
  }

  fail;
}


static StringObj
getPrintNamePoint(Point p)
{ char buf[200];

  sprintf(buf, "%ld,%ld", valInt(p->x), valInt(p->y));
  answer(CtoString(buf));
}


status
equalPoint(Point p1, Point p2)
{ if (p1->x == p2->x && p1->y == p2->y)
    succeed;
  fail;
}


status
copyPoint(Point p1, Point p2)
{ assign(p1, x, p2->x);
  assign(p1, y, p2->y);

  succeed;
}


static Point
getCopyPoint(Point p)
{ answer(answerObject(p->class, p->x, p->y, EAV));
}


status
setPoint(Point pt, Int x, Int y)
{ if ( notDefault(x) ) assign(pt, x, x);
  if ( notDefault(y) ) assign(pt, y, y);

  succeed;
}


status
offsetPoint(Point pt, Int x, Int y)
{ assign(pt, x, add(x,pt->x));
  assign(pt, y, add(y,pt->y));

  succeed;
}


static Point
getDifferencePoint(Point p, Point q)
{ answer(answerObject(ClassPoint, sub(p->x,q->x), sub(p->y,q->y),EAV));
}


int
get_distance_point(Point p, int x, int y)
{ double px = (double)valInt(p->x);
  double py = (double)valInt(p->y);
  double qx = (double)x;
  double qy = (double)y;
  double d = sqrt((qx-px)*(qx-px) + (qy-py)*(qy-py));

  return (int)d;
}


Int
getDistancePoint(Point p, Point q)
{ double px = (double)valInt(p->x);
  double py = (double)valInt(p->y);
  double qx = (double)valInt(q->x);
  double qy = (double)valInt(q->y);
  double d = sqrt((qx-px)*(qx-px) + (qy-py)*(qy-py));
  long di = (long)d;

  answer(toInt(di));
}


Point
getMidPoint(Point p, Point q)
{ answer(answerObject(ClassPoint,
		      toInt((valInt(p->x)+valInt(q->x)+1)/2),
		      toInt((valInt(p->y)+valInt(q->y)+1)/2),
		      EAV));
}


status
plusPoint(Point p, Point q)
{ assign(p, x, add(p->x,q->x));
  assign(p, y, add(p->y,q->y));

  succeed;
}


status
minusPoint(Point p, Point q)
{ assign(p, x, sub(p->x,q->x));
  assign(p, y, sub(p->y,q->y));

  succeed;
}


static status
mirrorPoint(Point p, Point q)
{ Int mx = ZERO, my = ZERO;

  if ( notDefault(q) )
  { mx = q->x; 
    my = q->y;
  }

  assign(p, x, sub(mx, p->x));
  assign(p, y, sub(my, p->y));

  succeed;
}


static Point
getPlusPoint(Point p1, Point p2)
{ Point p = getCopyPoint(p1);

  plusPoint(p, p2);
  
  answer(p);
}


static Point
getMinusPoint(Point p1, Point p2)
{ Point p = getCopyPoint(p1);

  minusPoint(p, p2);
  
  answer(p);
}


static Point
getMirrorPoint(Point p1, Point p2)
{ Point p = getCopyPoint(p1);

  mirrorPoint(p, p2);
  
  answer(p);
}


/* Type declaractions */

static char *T_offset[] = { "dx=int", "dy=int" };
static char *T_xADintD_yADintD[] = { "x=[int]", "y=[int]" };

/* Instance Variables */

static vardecl var_point[] =
{ IV(NAME_x, "int", IV_BOTH,
     NAME_dimension, "x-coordinate of point"),
  IV(NAME_y, "int", IV_BOTH,
     NAME_dimension, "y-coordinate of point")
};

/* Send Methods */

static senddecl send_point[] =
{ SM(NAME_initialise, 2, T_xADintD_yADintD, initialisePoint,
     DEFAULT, "Create point from x- and y-value"),
  SM(NAME_minus, 1, "point", minusPoint,
     NAME_calculate, "Subtract x and y of argument point"),
  SM(NAME_mirror, 1, "origin=[point]", mirrorPoint,
     NAME_calculate, "Mirror point around argument or (0,0)"),
  SM(NAME_offset, 2, T_offset, offsetPoint,
     NAME_calculate, "Move the point by given x and y"),
  SM(NAME_plus, 1, "point", plusPoint,
     NAME_calculate, "Add x- and y-values of argument point"),
  SM(NAME_set, 2, T_xADintD_yADintD, setPoint,
     NAME_calculate, "Set x- and y-values"),
  SM(NAME_equal, 1, "to=point", equalPoint,
     NAME_compare, "Test if argument is same position"),
  SM(NAME_copy, 1, "from=point", copyPoint,
     NAME_copy, "Copy x- and y values from the argument")
};

/* Get Methods */

static getdecl get_point[] =
{ GM(NAME_difference, 1, "point", "to=point", getDifferencePoint,
     NAME_calculate, "New point that reflects distance"),
  GM(NAME_distance, 1, "int", "to=point", getDistancePoint,
     NAME_calculate, "Integer for distance between points"),
  GM(NAME_mid, 1, "point", "to=point", getMidPoint,
     NAME_calculate, "New point in the middle between points"),
  GM(NAME_minus, 1, "point", "point", getMinusPoint,
     NAME_calculate, "New point p1 - p2"),
  GM(NAME_mirror, 1, "point", "origin=[point]", getMirrorPoint,
     NAME_calculate, "New point mirrored over argument"),
  GM(NAME_plus, 1, "point", "point", getPlusPoint,
     NAME_calculate, "New point p1 + p2"),
  GM(NAME_copy, 0, "point", NULL, getCopyPoint,
     NAME_copy, "New point with same <-x and <-y"),
  GM(NAME_convert, 1, "point", "event|char_array", getConvertPoint,
     NAME_textual, "Event <-position or the text `x,y'"),
  GM(NAME_printName, 0, "string", NULL, getPrintNamePoint,
     NAME_textual, "Printed representation as %d,%d")
};

/* Resources */

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

/* Class Declaration */

static Name point_termnames[] = { NAME_x, NAME_y };

ClassDecl(point_decls,
          var_point, send_point, get_point, rc_point,
          2, point_termnames,
          "$Rev$");

status
makeClassPoint(Class class)
{ return declareClass(class, &point_decls);
}
