/*  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>
#include <h/graphics.h>
#include <math.h>
#ifndef M_PI
#define M_PI (3.14159265358979323846)
#endif

#define COS(x) cos(((x) * M_PI) / 180.0)
#define SIN(x) sin(((x) * M_PI) / 180.0)

static status
initialiseArc(ArcObj a, Int radius, Real start_angle, Real size_angle)
{ initialiseJoint((Joint) a, ZERO, ZERO, ZERO, ZERO, DEFAULT);

  if ( isDefault(radius) )
    radius = getClassVariableValueObject(a, NAME_radius);
  if ( isDefault(start_angle) )
    start_angle = CtoReal(0.0);
  if ( isDefault(size_angle) )
    size_angle = CtoReal(90.0);

  assign(a, size,	  newObject(ClassSize, radius, radius, EAV));
  assign(a, position,	  newObject(ClassPoint, EAV));
  assign(a, start_angle,  start_angle);
  assign(a, size_angle,	  size_angle);
  assign(a, close,	  NAME_none);

  return requestComputeGraphical(a, DEFAULT);
}


void
points_arc(ArcObj a, int *sx, int *sy, int *ex, int *ey)
{ int cx = valInt(a->position->x);
  int cy = valInt(a->position->y);
  float start = valReal(a->start_angle);
  float size = valReal(a->size_angle);


  if ( sx )
    *sx = cx + rfloat((float) valInt(a->size->w) * COS(start));
  if ( sy )
    *sy = cy - rfloat((float) valInt(a->size->h) * SIN(start));
  if ( ex )
    *ex = cx + rfloat((float) valInt(a->size->w) * COS(start + size));
  if ( ey )
    *ey = cy - rfloat((float) valInt(a->size->h) * SIN(start + size));
}


static status
RedrawAreaArc(ArcObj a, Area area)
{ int x, y, w, h;
  int aw = valInt(a->size->w);
  int ah = valInt(a->size->h);
  int sx, sy, ex, ey;
  int cx, cy;

  initialiseDeviceGraphical(a, &x, &y, &w, &h);

  points_arc(a, &sx, &sy, &ex, &ey);
  cx = valInt(a->position->x);
  cy = valInt(a->position->y);

  r_thickness(valInt(a->pen));
  r_dash(a->texture);

  r_arc(cx - aw, cy - ah,
	2*aw, 2*ah,
	rfloat(valReal(a->start_angle)), rfloat(valReal(a->size_angle)),
	a->close,
	a->fill);

  if (notNil(a->first_arrow))
  { Any av[4];

    av[0] = toInt(sx);
    av[1] = toInt(sy);

    if ( valReal(a->size_angle) >= 0.0 )
    { av[2] = toInt(sx+(sy-cy));
      av[3] = toInt(sy-(sx-cx));
    } else
    { av[2] = toInt(sx-(sy-cy));
      av[3] = toInt(sy+(sx-cx));
    }

    if ( qadSendv(a->first_arrow, NAME_points, 4, av) )
    { assign(a->first_arrow, displayed, ON);
      ComputeGraphical(a->first_arrow);
      RedrawArea(a->first_arrow, area);
    }
  }
  if (notNil(a->second_arrow))
  { Any av[4];

    av[0] = toInt(ex);
    av[1] = toInt(ey);

    if ( valReal(a->size_angle) >= 0.0 )
    { av[2] = toInt(ex-(ey-cy));
      av[3] = toInt(ey+(ex-cx));
    } else
    { av[2] = toInt(ex+(ey-cy));
      av[3] = toInt(ey-(ex-cx));
    }

    if ( qadSendv(a->second_arrow, NAME_points, 4, av) )
    { assign(a->second_arrow, displayed, ON);
      ComputeGraphical(a->second_arrow);
      RedrawArea(a->second_arrow, area);
    }
  }

  return RedrawAreaGraphical(a, area);
}


static status
angleInArc(ArcObj a, int angle)
{ int start = rfloat(valReal(a->start_angle));
  int size  = rfloat(valReal(a->size_angle));

  if ( size < 0 )
  { start += size;
    size = -size;
  }
  while(start < 0)
    start += 360;
  start = start % 360;

  if ( (angle >= start && angle <= start + size) ||
       (angle <  start && angle <= start + size - 360) )
    succeed;

  fail;
}


static void
includeArrowsInAreaArc(ArcObj a)
{ if ( notNil(a->first_arrow) || notNil(a->second_arrow) )
  { int sx, sy, ex, ey;
    int cx, cy;
    Any av[4];

    points_arc(a, &sx, &sy, &ex, &ey);
    cx = valInt(a->position->x);
    cy = valInt(a->position->y);

    if ( notNil(a->first_arrow) )
    { av[0] = toInt(sx);
      av[1] = toInt(sy);

      if ( valReal(a->size_angle) >= 0.0 )
      { av[2] = toInt(sx+(sy-cy));
	av[3] = toInt(sy-(sx-cx));
      } else
      { av[2] =	toInt(sx-(sy-cy));
	av[3] = toInt(sy+(sx-cx));
      }

      if ( qadSendv(a->first_arrow, NAME_points, 4, av) )
      { ComputeGraphical(a->first_arrow);
	unionNormalisedArea(a->area, a->first_arrow->area);
      }
    }
    if ( notNil(a->second_arrow) )
    { av[0] = toInt(ex);
      av[1] = toInt(ey);

      if ( valReal(a->size_angle) >= 0.0 )
      { av[2] = toInt(ex-(ey-cy));
	av[3] = toInt(ey+(ex-cx));
      } else
      { av[2] = toInt(ex+(ey-cy));
	av[3] = toInt(ey-(ex-cx));
      }

      if ( qadSendv(a->second_arrow, NAME_points, 4, av) )
      { ComputeGraphical(a->second_arrow);
	unionNormalisedArea(a->area, a->second_arrow->area);
      }
    }
  }
}


static status
computeArc(ArcObj a)
{ if ( notNil(a->request_compute) )
  { int minx, miny, maxx, maxy;
    int sx, sy, ex, ey;
    int px = valInt(a->position->x);
    int py = valInt(a->position->y);
    int sw = valInt(a->size->w);
    int sh = valInt(a->size->h);

    points_arc(a, &sx, &sy, &ex, &ey);
    minx = min(sx, ex);
    maxx = max(sx, ex);
    miny = min(sy, ey);
    maxy = max(sy, ey);

    if ( angleInArc(a, 0) )
      maxx = max(maxx, px + sw);
    if ( angleInArc(a, 90) )
      miny = min(miny, py - sh);
    if ( angleInArc(a, 180) )
      minx = min(minx, px - sw);
    if ( angleInArc(a, 270) )
      maxy = max(maxy, py + sh);

    if ( a->close == NAME_pieSlice ||
	 (a->close == NAME_none && notNil(a->fill)) )
    { maxx = max(maxx, px);
      minx = min(minx, px);
      miny = min(miny, py);
      maxy = max(maxy, py);
    }

    minx--;
    miny--;
    maxy++;
    maxx++;

    if ( a->selected == ON )		/* account for selection blobs */
    { minx -= 3;
      miny -= 3;
      maxx += 3;
      maxy += 3;
    }

    CHANGING_GRAPHICAL(a,
		       { setArea(a->area, toInt(minx), toInt(miny),
				          toInt(maxx-minx), toInt(maxy-miny));
			 includeArrowsInAreaArc(a);
		         changedEntireImageGraphical(a);
		       });

    assign(a, request_compute, NIL);
  }

  succeed;
}


static status
geometryArc(ArcObj a, Int x, Int y, Int w, Int h)
{ Int ox, oy;

  ox = isDefault(x) ? ZERO : sub(x, a->area->x);
  oy = isDefault(y) ? ZERO : sub(y, a->area->y);

  CHANGING_GRAPHICAL(a,
		     offsetPoint(a->position, ox, oy);
		     requestComputeGraphical(a, DEFAULT));

  succeed;
}


static status
setArc(ArcObj a, Int x, Int y, Int radius, float start, float size)
{ int changed = 0;

  if ( a->position->x != x || a->position->y != y )
  { setPoint(a->position, x, y);
    changed++;
  }
  if ( a->size->w != radius || a->size->h != radius )
  { setSize(a->size, radius, radius);
    changed++;
  }

  if ( valReal(a->start_angle) != start || valReal(a->size_angle) != size )
  { setReal(a->start_angle, start);
    setReal(a->size_angle, size);
    changed++;
  }

  if ( changed )
    requestComputeGraphical(a, DEFAULT);

  succeed;
}


static status
radiusArc(ArcObj a, Int r)
{ if ( a->size->w != r || a->size->h != r )
  { setSize(a->size, r, r);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}


static status
positionArc(ArcObj a, Point pos)
{ if ( !equalPoint(a->position, pos) )
  { copyPoint(a->position, pos);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}


static status
resizeArc(ArcObj a, Real xfactor, Real yfactor, Point origin)
{ float xf, yf;
  int ox = valInt(a->position->x);
  int oy = valInt(a->position->y);
  int nx, ny, nw, nh;

  init_resize_graphical(a, xfactor, yfactor, origin, &xf, &yf, &ox, &oy);
  if ( xf == 1.0 && yf == 1.0 )
    succeed;

  nx = ox + rfloat((float) (valInt(a->position->x)-ox) * xf);
  ny = oy + rfloat((float) (valInt(a->position->y)-oy) * yf);
  nw = rfloat((float) valInt(a->size->w) * xf);
  nh = rfloat((float) valInt(a->size->h) * yf);

  setSize(a->size, toInt(nw), toInt(nh));
  setPoint(a->position, toInt(nx), toInt(ny));

  return requestComputeGraphical(a, DEFAULT);
}


static Int
getRadiusArc(ArcObj a)
{ answer(a->size->w);
}


static Point
getStartArc(ArcObj a)
{ int sx, sy;

  points_arc(a, &sx, &sy, NULL, NULL);
  answer(answerObject(ClassPoint, toInt(sx), toInt(sy), EAV));
}


static Point
getEndArc(ArcObj a)
{ int ex, ey;

  points_arc(a, NULL, NULL, &ex, &ey);
  answer(answerObject(ClassPoint, toInt(ex), toInt(ey), EAV));
}


static status
sizeArc(ArcObj a, Size sz)
{ if ( !equalSize(a->size, sz) )
  { copySize(a->size, sz);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}


static status
startAngleArc(ArcObj a, Real s)
{ if ( valReal(a->start_angle) != valReal(s) )
  { valueReal(a->start_angle, s);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}


static status
sizeAngleArc(ArcObj a, Real e)
{ if ( valReal(a->size_angle) != valReal(e) )
  { valueReal(a->size_angle, e);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}


static status
endAngleArc(ArcObj a, Real e)
{ float size = valReal(e) - valReal(a->start_angle);
  if ( size < 0.0 )
    size += 360.0;

  if ( valReal(a->size_angle) != size )
  { setReal(a->size_angle, size);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}


static status
closeArc(ArcObj a, Name how)
{ if ( a->close != how )
  { assign(a, close, how);
    requestComputeGraphical(a, DEFAULT);
  }

  succeed;
}



		/********************************
		*        SPECIFICATIONS		*
		********************************/

static status
connectAngleArc(ArcObj a, Line l1, Line l2)
{ Point is;

  if ( !(is = getIntersectionLine(l1, l2)) )
    fail;				/* no intersection */

  positionArc(a, is);
  startAngleArc(a, getAngleLine(l1, is));
  endAngleArc(a, getAngleLine(l2, is));
  doneObject(is);

  succeed;
}


static status
pointsArc(ArcObj a, Int Sx, Int Sy, Int Ex, Int Ey, Int D)
{ int sx, sy, ex, ey, d;
  int cx, cy;
  int dx, dy;
  int l, dl;
  int radius;
  float start, end, size;

  sx = valInt(Sx), sy = valInt(Sy), ex = valInt(Ex), ey = valInt(Ey);
  d = valInt(D);
  DEBUG(NAME_arc, Cprintf("ArcObj %d,%d --> %d,%d (%d)\n", sx, sy, ex, ey, d));

  cx = (sx + ex + 1)/2;			/* center of segment line */
  cy = (sy + ey + 1)/2;

  dx = ex - sx;
  dy = ey - sy;
  l = isqrt(dx*dx + dy*dy);
  dl = (l*l)/(8*d) - d/2;
  dx = (dx * dl)/l;
  dy = (dy * dl)/l;

  cx -= dy;				/* center of circle */
  cy += dx;
  radius = isqrt((cx-sx)*(cx-sx) + (cy-sy)*(cy-sy));
  DEBUG(NAME_arc, Cprintf("\tcircle from %d,%d, radius %d\n", cx, cy, radius));

  if ( ex != cx || ey != cy )
  { start = atan2((float)(cy-ey), (float)(ex-cx));
    if ( start < 0.0 )
      start = 2.0 * M_PI + start;
    start = (start * 180.0) / M_PI;

    end = atan2((float)(cy-sy), (float)(sx-cx));
    if ( end < 0.0 )
      end = 2.0 * M_PI + end;
    end = (end * 180.0) / M_PI;
  } else
  { start = end = 0.0;
  }
  DEBUG(NAME_arc, Cprintf("\t%d --> %d degrees\n",
			  (int) ((start * 360.0)/(2.0 * M_PI)),
			  (int) ((end * 360.0)/(2.0 * M_PI))));

  if ( d < 0 )
  { float x = end;
    end = start;
    start = x;
  }

  size = end - start;
  if ( size < 0.0 )
    size += 360.0;

  if ( d > 0 )
  { start += size;
    size = -size;
  }

  return setArc(a, toInt(cx), toInt(cy), toInt(radius), start, size);
}


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

/* Type declaractions */

static char *T_connectAngle[] =
        { "line", "line" };
static char *T_initialise[] =
        { "radius=[int]", "start=[real]", "size=[real]" };
static char *T_resize[] =
        { "real", "[real]", "[point]" };
static char *T_points[] =
        { "start_x=int", "start_y=int", "end_x=int", "end_y=int", "curvature=int" };
static char *T_geometry[] =
        { "x=[int]", "y=[int]", "width=[int]", "height=[int]" };

/* Instance Variables */

static vardecl var_arc[] =
{ SV(NAME_position, "point", IV_GET|IV_STORE, positionArc,
     NAME_area, "Position of the arc"),
  SV(NAME_size, "size", IV_GET|IV_STORE, sizeArc,
     NAME_area, "Size of the ellipse I'm part of"),
  SV(NAME_startAngle, "real", IV_GET|IV_STORE, startAngleArc,
     NAME_pie, "Start angle (degrees)"),
  SV(NAME_sizeAngle, "real", IV_GET|IV_STORE, sizeAngleArc,
     NAME_pie, "Size (degrees)"),
  SV(NAME_close, "{none,pie_slice,chord}", IV_GET|IV_STORE, closeArc,
     NAME_appearance, "How the arc is closed"),
  SV(NAME_fill, TYPE_FILL, IV_GET|IV_STORE, fillGraphical,
     NAME_appearance, "Fill pattern for the slice")
};

/* Send Methods */

static senddecl send_arc[] =
{ SM(NAME_compute, 0, NULL, computeArc,
     DEFAULT, "Compute the bounding box area"),
  SM(NAME_geometry, 4, T_geometry, geometryArc,
     DEFAULT, "Only move the arc"),
  SM(NAME_initialise, 3, T_initialise, initialiseArc,
     DEFAULT, "Create ArcObj from radius, start_angle and size_angle (degrees)"),
  SM(NAME_resize, 3, T_resize, resizeArc,
     DEFAULT, "Resize arc with specified factor"),
  SM(NAME_connectAngle, 2, T_connectAngle, connectAngleArc,
     NAME_area, "Connect both lines with an angle"),
  SM(NAME_radius, 1, "int", radiusArc,
     NAME_dimension, "->width and ->height"),
  SM(NAME_endAngle, 1, "real", endAngleArc,
     NAME_pie, "Set ->size_angle to argument - <-start_angle"),
  SM(NAME_points, 5, T_points, pointsArc,
     NAME_tip, "ArcObj between two points")
};

/* Get Methods */

static getdecl get_arc[] =
{ GM(NAME_radius, 0, "int", NULL, getRadiusArc,
     NAME_area, "Equivalent to <-width"),
  GM(NAME_end, 0, "point", NULL, getEndArc,
     NAME_tip, "End position of arc"),
  GM(NAME_start, 0, "point", NULL, getStartArc,
     NAME_tip, "Start position of arc")
};

/* Resources */

static classvardecl rc_arc[] =
{ RC(NAME_radius, "int", "30",
     "Default radius")
};

/* Class Declaration */

static Name arc_termnames[] = { NAME_radius, NAME_startAngle, NAME_sizeAngle };

ClassDecl(arc_decls,
          var_arc, send_arc, get_arc, rc_arc,
          3, arc_termnames);


status
makeClassArc(Class class)
{ declareClass(class, &arc_decls);

  cloneStyleVariableClass(class, NAME_fill, NAME_reference);
  setRedrawFunctionClass(class, RedrawAreaArc);

  succeed;
}
