/*
 * Arc.c -- Implementation of Arc item.
 *
 * Authors		: Patrick Lecoanet.
 * Creation date	: Wed Mar 30 16:24:09 1994
 *
 * $Id$
 */

/*
 *  Copyright (c) 1993 - 1999 CENA, Patrick Lecoanet --
 *
 * This code is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This code 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this code; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */


#include <malloc.h>

#include "Item.h"
#include "Geo.h"
#include "Draw.h"
#include "Types.h"
#include "WidgetInfo.h"
#include "Image.h"


static const char rcsid[] = "$Id$";
static const char compile_id[]="$Compile: " __FILE__ " " __DATE__ " " __TIME__ " $";


/*
 * Bit offset of flags.
 */
#define FILLED_BIT	1<<0	/* If the arc is filled with color/pattern */
#define CLOSED_BIT	1<<1	/* If the arc outline is closed */
#define PIE_SLICE_BIT	1<<2	/* If the arc is closed as a pie slice or a chord */

#define FIRST_END_OK	1<<3
#define LAST_END_OK	1<<4
#define USING_POLY_BIT	1<<5


static double Pick(Item item, ZnPoint *p, Item start_item, int aperture,
		   Item *a_item, int *a_part);


/*
 **********************************************************************************
 *
 * Specific Arc item record.
 *
 **********************************************************************************
 */
typedef struct _ArcItemStruct {
  ItemStruct	header;
  
  /* Public data */
  ZnPoint	coords[2];
  int		start_angle;
  int		angle_extent;
  Pixmap	line_pattern;
  Pixmap	fill_pattern;
  ZnColorGradient fill_color;
  ZnGradientGeom  grad_geom;
  ZnColor	line_color;
  int		line_width;
  LineStyle	line_style;
  ZnLineEnd	first_end;
  ZnLineEnd	last_end;
  char		*tile_name;
  unsigned char flags;

  /* Private data */
  ZnPoint	orig;
  ZnPoint	corner;
  ZnPoint	center1;
  ZnPoint	center2;
  ZnImage	tile;
  ZnList	render_shape;
} ArcItemStruct, *ArcItem;


static ZnAttrConfig	arc_attrs[] = {
  { ZN_CONFIG_BOOL, "-closed", NULL,
    Tk_Offset(ArcItemStruct, flags), CLOSED_BIT, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_BOOL, "-composerotation", NULL,
    Tk_Offset(ArcItemStruct, header.flags), COMPOSE_ROTATION_BIT,
    ZN_COORDS_FLAG, False },
  { ZN_CONFIG_BOOL, "-composescale", NULL,
    Tk_Offset(ArcItemStruct, header.flags), COMPOSE_SCALE_BIT,
    ZN_COORDS_FLAG, False },
  { ZN_CONFIG_ANGLE, "-extent", NULL,
    Tk_Offset(ArcItemStruct, angle_extent), 0, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_GRADIENT_COLOR, "-fillcolor", NULL,
    Tk_Offset(ArcItemStruct, fill_color), 0, ZN_DRAW_FLAG, False },
  { ZN_CONFIG_BOOL, "-filled", NULL,
    Tk_Offset(ArcItemStruct, flags), FILLED_BIT, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_PATTERN, "-fillpattern", NULL,
    Tk_Offset(ArcItemStruct, fill_pattern), 0, ZN_DRAW_FLAG, False },
  { ZN_CONFIG_LINE_END, "-firstend", NULL,
    Tk_Offset(ArcItemStruct, first_end), 0, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_GRADIENT_GEOM, "-gradient", NULL,
    Tk_Offset(ArcItemStruct, grad_geom), 0, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_LINE_END, "-lastend", NULL,
    Tk_Offset(ArcItemStruct, last_end), 0, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_COLOR, "-linecolor", NULL,
    Tk_Offset(ArcItemStruct, line_color), 0,
    ZN_DRAW_FLAG|ZN_BORDER_FLAG, False },
  { ZN_CONFIG_PATTERN, "-linepattern", NULL,
    Tk_Offset(ArcItemStruct, line_pattern), 0, ZN_DRAW_FLAG, False },
  { ZN_CONFIG_LINE_STYLE, "-linestyle", NULL,
    Tk_Offset(ArcItemStruct, line_style), 0, ZN_DRAW_FLAG, False },
  { ZN_CONFIG_DIM, "-linewidth", NULL,
    Tk_Offset(ArcItemStruct, line_width), 0, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_BOOL, "-pieslice", NULL,
    Tk_Offset(ArcItemStruct, flags), PIE_SLICE_BIT, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_PRI, "-priority", NULL,
    Tk_Offset(ArcItemStruct, header.priority), 0,
    ZN_DRAW_FLAG|ZN_REPICK_FLAG, False },
  { ZN_CONFIG_BOOL, "-sensitive", NULL,
    Tk_Offset(ArcItemStruct, header.flags), SENSITIVE_BIT,
    ZN_REPICK_FLAG, False },
  { ZN_CONFIG_ANGLE, "-startangle", NULL,
    Tk_Offset(ArcItemStruct, start_angle), 0, ZN_COORDS_FLAG, False },
  { ZN_CONFIG_TAGS, "-tags", NULL,
    Tk_Offset(ArcItemStruct, header.tags), 0, 0, False },
  { ZN_CONFIG_IMAGE, "-tile", NULL,
    Tk_Offset(ArcItemStruct, tile_name), 0,
    ZN_DRAW_FLAG|ZN_TILE_FLAG, False },
  { ZN_CONFIG_BOOL, "-visible", NULL,
    Tk_Offset(ArcItemStruct, header.flags), VISIBLE_BIT,
    ZN_DRAW_FLAG|ZN_REPICK_FLAG|ZN_VIS_FLAG, False },
  
  { ZN_CONFIG_END, NULL, NULL, 0, 0, 0 }
};


/*
 **********************************************************************************
 *
 * ArcTileChange --
 *
 **********************************************************************************
 */
static void
ArcTileChange(ClientData	client_data,
	      int		x,
	      int		y,
	      int		width,
	      int		height,
	      int		image_width,
	      int		image_height)
{
  ArcItem	arc = (ArcItem) client_data;

  InvalidateImage(arc->tile_name);
  ITEM.Invalidate((Item) arc, ZN_COORDS_FLAG);
}


/*
 **********************************************************************************
 *
 * Init --
 *
 **********************************************************************************
 */
static int
Init(Item		item,
     int		*argc,
      Tcl_Obj *CONST	*args[])
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;
  Tcl_Obj	**elems;
  int		num_elems;

  /* Init attributes */
  SET(item->flags, VISIBLE_BIT);
  SET(item->flags, SENSITIVE_BIT);
  SET(item->flags, COMPOSE_ROTATION_BIT);
  SET(item->flags, COMPOSE_SCALE_BIT);
  item->priority = DEFAULT_ARC_PRIORITY;

  arc->start_angle = 0;
  arc->angle_extent = 360;
  CLEAR(arc->flags, FILLED_BIT);
  CLEAR(arc->flags, CLOSED_BIT);
  CLEAR(arc->flags, PIE_SLICE_BIT);
  CLEAR(arc->flags, USING_POLY_BIT);
  arc->line_pattern = ZnUnspecifiedPattern;
  arc->fill_pattern = ZnUnspecifiedPattern;
  arc->line_style = LINE_SIMPLE;
  arc->line_width = 1;
  arc->first_end = arc->last_end = NULL;
  arc->tile_name = "";
  arc->tile = ZnUnspecifiedImage;
  arc->render_shape = NULL;
  
  if (*argc < 1) {
    Tcl_AppendResult(wi->interp, " arc coords expected", NULL);
    return ZN_ERROR;
  }
  if ((Tcl_ListObjGetElements(wi->interp, (*args)[0], &num_elems, &elems) == ZN_ERROR) ||
      (num_elems != 4) ||
      (Tcl_GetDoubleFromObj(wi->interp, elems[0], &arc->coords[0].x) == ZN_ERROR) ||
      (Tcl_GetDoubleFromObj(wi->interp, elems[1], &arc->coords[0].y) == ZN_ERROR) ||
      (Tcl_GetDoubleFromObj(wi->interp, elems[2], &arc->coords[1].x) == ZN_ERROR) ||
      (Tcl_GetDoubleFromObj(wi->interp, elems[3], &arc->coords[1].y) == ZN_ERROR)) {
    Tcl_AppendResult(wi->interp, " malformed arc coords", NULL);
    return ZN_ERROR;
  };
  (*args)++;
  (*argc)--;

  arc->fill_color = ZnGetColorGradient(wi->interp, wi->win,
				       ZnNameOfColor(wi->fore_color));
  arc->line_color = ZnGetColorByValue(wi->win, wi->fore_color);
  arc->grad_geom = NULL;

  return ZN_OK;
}


/*
 **********************************************************************************
 *
 * Clone --
 *
 **********************************************************************************
 */
static void
Clone(Item	item)
{
  ArcItem	arc = (ArcItem) item;
  WidgetInfo	*wi = item->wi;
  char		*text;

  if (strlen(arc->tile_name) != 0) {
    text = ZnMalloc((strlen(arc->tile_name) + 1) * sizeof(char));
    strcpy(text, arc->tile_name);
    arc->tile_name = text;
    arc->tile = Tk_GetImage(wi->interp, wi->win, arc->tile_name,
			    ArcTileChange, (ClientData) arc);
  }
  if (arc->first_end) {
    LineEndDuplicate(arc->first_end);
  }
  if (arc->last_end) {
    LineEndDuplicate(arc->last_end);
  }
  if (arc->line_pattern != ZnUnspecifiedPattern) {
    arc->line_pattern = Tk_GetBitmap(wi->interp, wi->win,
				     Tk_NameOfBitmap(wi->dpy, arc->line_pattern));
  }
  if (arc->fill_pattern != ZnUnspecifiedPattern) {
    arc->fill_pattern = Tk_GetBitmap(wi->interp, wi->win,
				     Tk_NameOfBitmap(wi->dpy, arc->fill_pattern));
  }
  arc->line_color = ZnGetColorByValue(wi->win, arc->line_color);
  arc->fill_color = ZnGetColorGradientByValue(arc->fill_color);
  if (arc->grad_geom) {
    arc->grad_geom = GradientGeomDuplicate(arc->grad_geom);
  }
  arc->render_shape = NULL;
}


/*
 **********************************************************************************
 *
 * Destroy --
 *
 **********************************************************************************
 */
static void
Destroy(Item	item)
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;

  if (arc->render_shape) {
    ZnListFree(arc->render_shape);
  }
  if (arc->first_end) {
    LineEndDelete(arc->first_end);
  }
  if (arc->last_end) {
    LineEndDelete(arc->last_end);
  }
  if (arc->tile != ZnUnspecifiedImage) {
    Tk_FreeImage(arc->tile);
    arc->tile = ZnUnspecifiedImage;
  }
  if (strlen(arc->tile_name) != 0) {
    ZnFree(arc->tile_name);
  }
  if (arc->line_pattern != ZnUnspecifiedPattern) {
    Tk_FreeBitmap(wi->dpy, arc->line_pattern);
  }
  if (arc->fill_pattern != ZnUnspecifiedPattern) {
    Tk_FreeBitmap(wi->dpy, arc->fill_pattern);
  }
  ZnFreeColorGradient(arc->fill_color);
  ZnFreeColor(arc->line_color);
  if (arc->grad_geom) {
    GradientGeomDelete(arc->grad_geom);
  }
}


/*
 **********************************************************************************
 *
 * Setup flags to control the precedence between the
 * graphical attributes.
 *
 **********************************************************************************
 */
static void
SetRenderFlags(ArcItem	arc)
{
  ASSIGN(arc->flags, FIRST_END_OK,
	 (arc->first_end != NULL) && ISCLEAR(arc->flags, CLOSED_BIT) &&
	 ISCLEAR(arc->flags, FILLED_BIT) && arc->line_width
	 /*&& ISCLEAR(arc->flags, RELIEF_OK)*/);

  ASSIGN(arc->flags, LAST_END_OK,
	 (arc->last_end != NULL) && ISCLEAR(arc->flags, CLOSED_BIT) &&
	 ISCLEAR(arc->flags, FILLED_BIT) && arc->line_width
	 /*&& ISCLEAR(arc->flags, RELIEF_OK)*/);
}


/*
 **********************************************************************************
 *
 * Configure --
 *
 **********************************************************************************
 */
static int
Configure(Item		item,
	  int		argc,
	  Tcl_Obj *CONST argv[],
	  int		*flags)
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;
  int		status = ZN_OK;

  status = ITEM_P.ConfigureAttributes((char *) item, -1, argc, argv, flags);

  if (ISSET(*flags, ZN_TILE_FLAG)) {
    Tk_Image	tile;

    if (strcmp(arc->tile_name, "") != 0) {
      tile = Tk_GetImage(wi->interp, wi->win, arc->tile_name,
			  ArcTileChange, (ClientData) arc);
      if (tile == NULL) {
	/*
	 * The name will not be in sync with the image in
	 * this case.
	 */
	status = ZN_ERROR;
      }
    }
    else {
      tile = ZnUnspecifiedImage;
    }
    if (arc->tile != ZnUnspecifiedImage) {
      Tk_FreeImage(arc->tile);
    }
    arc->tile = tile;
  }

  SetRenderFlags(arc);
  
  return status;
}


/*
 **********************************************************************************
 *
 * Query --
 *
 **********************************************************************************
 */
static int
Query(Item		item,
      int		argc,
      Tcl_Obj *CONST	argv[])
{
  if (ITEM_P.QueryAttribute((char *) item, -1, argv[0]) == ZN_ERROR) {
    return ZN_ERROR;
  }  

  return ZN_OK;
}


/*
 * Tangent --
 *	Compute a point describing the arc tangent at the first/last
 *	end of the arc. The point is on the tangent segment next to
 *	the arc (ie: it is suitable for drawing arrows).
 */
void
Tangent(ArcItem	arc,
	ZnBool	first,
	ZnPoint	*p)
{
  double	a2, b2, w_2, h_2;
  double	angle;
  ZnPoint	p1, center;

  if (first) {
    angle = DegreesToRadian(arc->start_angle);
  }
  else {
    angle = DegreesToRadian(arc->start_angle + arc->angle_extent);
  }
  p1.x = cos(angle);
  p1.y = sin(angle);
  w_2 = (arc->corner.x - arc->orig.x) / 2.0;
  h_2 = (arc->corner.y - arc->orig.y) / 2.0;
  center.x = (arc->orig.x + arc->corner.x) / 2.0;
  center.y = (arc->orig.y + arc->corner.y) / 2.0;

  /*
   * Slope of the initial segment.
   *
   * a1 = (center->y - p1.y) / (center->x - p1.x);
   * a2 = -1/a1;
   */
  a2 = - p1.x / p1.y;
  b2 = p1.y - a2*p1.x;

  if (p1.y == 0.0) {
    p->x = p1.x;
    if (!first) {
      p->y = p1.y - 10.0;
    }
    else {
      p->y = p1.y + 10.0;
    }
  }
  else {
    if ((!first && (p1.y < 0.0)) || (first && (p1.y > 0.0))) {
      p->x = p1.x - 10.0;
    }
    else {
      p->x = p1.x + 10.0;
    }
    p->y = a2*p->x + b2;
  }
  p->x = center.x + REAL_TO_INT(p->x*w_2);
  p->y = center.y + REAL_TO_INT(p->y*h_2);
}


/*
 **********************************************************************************
 *
 * ComputeCoordinates --
 *
 **********************************************************************************
 */
static void
ComputeCoordinates(Item		item,
		   ZnBool	force)
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;
  ZnReal	angle, sin1, cos1, sin2, cos2;
  ZnReal	tmp, w_2, h_2, center_x, center_y;
  int		num_p, i;
  ZnPoint	*p_list, p;
  ZnPoint	end_points[LINE_END_POINTS];
  ZnReal	width_2, height_2, ox, oy;
  
  ResetBBox(&item->item_bounding_box);
  /*
   * If it is neither filled nor outlined, then nothing to show.
   */
  if (!arc->line_width && ISCLEAR(arc->flags, FILLED_BIT)) {
    return;
  }

  /*
   * Special casing for ellipse rotation and gradient.
   */
  ZnTransfoDecompose(wi->current_transfo, NULL, NULL, &angle, NULL);
  width_2 = (arc->coords[1].x - arc->coords[0].x)/2.0;
  height_2 = (arc->coords[1].y - arc->coords[0].y)/2.0;
  if (((angle >= PRECISION_LIMIT) && ((width_2 - height_2) > PRECISION_LIMIT)) ||
      arc->grad_geom) {
    SET(arc->flags, USING_POLY_BIT);
    if (!arc->render_shape) {
      arc->render_shape = ZnListNew(4, sizeof(ZnPoint));
    }
    GetArcPath(DegreesToRadian(arc->start_angle),
	       DegreesToRadian(arc->start_angle+arc->angle_extent),
	       (ISCLEAR(arc->flags, CLOSED_BIT) ? 0 :
		ISCLEAR(arc->flags, PIE_SLICE_BIT) ? 1 : 2), arc->render_shape);
    p_list = (ZnPoint *) ZnListArray(arc->render_shape);
    num_p = ZnListSize(arc->render_shape);
    ox = (arc->coords[1].x + arc->coords[0].x)/2.0;
    oy = (arc->coords[1].y + arc->coords[0].y)/2.0;
    for (i = 0; i < num_p; i++, p_list++) {
      p.x = ox + p_list->x*width_2;
      p.y = oy + p_list->y*height_2;
      ZnTransformPoint(wi->current_transfo, &p, p_list);
      AddPointToBBox(&item->item_bounding_box, p_list->x, p_list->y);
    }

    tmp = (arc->line_width + 1.0) / 2.0 + 1.0;
    item->item_bounding_box.orig.x -= tmp;
    item->item_bounding_box.orig.y -= tmp;
    item->item_bounding_box.corner.x += tmp;
    item->item_bounding_box.corner.y += tmp;

    /*
     * Add the arrows if any.
     */
    if (ISSET(arc->flags, FIRST_END_OK)) {
      GetLineEnd(p_list, p_list+1, arc->line_width, CapRound,
		 arc->first_end, end_points);
      AddPointsToBBox(&item->item_bounding_box, end_points, LINE_END_POINTS);
    }
    if (ISSET(arc->flags, LAST_END_OK)) {
      GetLineEnd(&p_list[num_p-1], &p_list[num_p-2], arc->line_width, CapRound,
		 arc->last_end, end_points);
      AddPointsToBBox(&item->item_bounding_box, end_points, LINE_END_POINTS);
    }
    return;
  }

  /*
   *******		********			**********
   * This part is for X drawn arcs: not rotated.
   *******		********			**********
   */
  CLEAR(arc->flags, USING_POLY_BIT);
  ZnTransformPoint(wi->current_transfo, &arc->coords[0], &arc->orig);
  ZnTransformPoint(wi->current_transfo, &arc->coords[1], &arc->corner);

  if (arc->orig.x > arc->corner.x) {
    tmp = arc->orig.x;
    arc->orig.x = arc->corner.x;
    arc->corner.x = tmp;
  }
  if (arc->orig.y > arc->corner.y) {
    tmp = arc->orig.y;
    arc->orig.y = arc->corner.y;
    arc->corner.y = tmp;
  }

  /*
   * now compute the two points at the centers of the ends of the arc.
   * We first compute the position for a unit circle and then scale
   * to fit the shape.
   * Angles are running clockwise and y coordinates are inverted.
   */
  angle = DegreesToRadian(arc->start_angle);
  sin1 = sin(angle);
  cos1 = cos(angle);
  angle += DegreesToRadian(arc->angle_extent);
  sin2 = sin(angle);
  cos2 = cos(angle);
  
  w_2 = (arc->corner.x - arc->orig.x) / 2;
  h_2 = (arc->corner.y - arc->orig.y) / 2;
  center_x = (arc->corner.x + arc->orig.x) / 2;
  center_y = (arc->corner.y + arc->orig.y) / 2;

  arc->center1.x = center_x + REAL_TO_INT(cos1*w_2);
  arc->center1.y = center_y + REAL_TO_INT(sin1*h_2);
  arc->center2.x = center_x + REAL_TO_INT(cos2*w_2);
  arc->center2.y = center_y + REAL_TO_INT(sin2*h_2);
  
  /*
   * Add the ends centers to the bbox.
   */
  AddPointToBBox(&item->item_bounding_box, arc->center1.x, arc->center1.y);
  AddPointToBBox(&item->item_bounding_box, arc->center2.x, arc->center2.y);
  
  /*
   * If the arc is filled or if the outline is closed in pie slice,
   * add the center of the arc.
   */
  if ((ISSET(arc->flags, FILLED_BIT) || ISSET(arc->flags, CLOSED_BIT)) &&
      ISSET(arc->flags, PIE_SLICE_BIT)) {
    AddPointToBBox(&item->item_bounding_box, center_x, center_y);
  }
  
  /*
   * Then add the 3-o'clock, 6-o'clock, 9-o'clock, 12-o'clock position
   * as required.
   */
  tmp = -arc->start_angle;
  if (tmp < 0) {
    tmp += 360;
  }
  if ((tmp < arc->angle_extent) || ((tmp - 360) > arc->angle_extent)) {
    AddPointToBBox(&item->item_bounding_box, arc->corner.x, center_y);
  }

  tmp = 180 - arc->start_angle;
  if (tmp < 0) {
    tmp += 360;
  }
  if ((tmp < arc->angle_extent) || ((tmp - 360) > arc->angle_extent)) {
    AddPointToBBox(&item->item_bounding_box, arc->orig.x, center_y);
  }
  
  tmp = 90 - arc->start_angle;
  if (tmp < 0) {
    tmp += 360;
  }
  if ((tmp < arc->angle_extent) || ((tmp - 360) > arc->angle_extent)) {
    AddPointToBBox(&item->item_bounding_box, center_x, arc->corner.y);
  }

  tmp = 270 - arc->start_angle;
  if (tmp < 0) {
    tmp += 360;
  }
  if ((tmp < arc->angle_extent) || ((tmp - 360) > arc->angle_extent)) {
    AddPointToBBox(&item->item_bounding_box, center_x, arc->orig.y);
  }
  
  /*
   * Now take care of the arc outline width plus one pixel of margin.
   */
  tmp = (arc->line_width + 1.0) / 2.0 + 1.0;
  item->item_bounding_box.orig.x -= tmp;
  item->item_bounding_box.orig.y -= tmp;
  item->item_bounding_box.corner.x += tmp;
  item->item_bounding_box.corner.y += tmp;

  /*
   * Then add the arrows if any.
   */
  if (ISSET(arc->flags, FIRST_END_OK)) {
    Tangent(arc, True, &p);
    GetLineEnd(&arc->center1, &p, arc->line_width, CapRound,
	       arc->first_end, end_points);
    AddPointsToBBox(&item->item_bounding_box, end_points, LINE_END_POINTS);
  }
  if (ISSET(arc->flags, LAST_END_OK)) {
    Tangent(arc, False, &p);
    GetLineEnd(&arc->center2, &p, arc->line_width, CapRound,
	       arc->last_end, end_points);
    AddPointsToBBox(&item->item_bounding_box, end_points, LINE_END_POINTS);
  }
}


/*
 **********************************************************************************
 *
 * ToArea --
 *	Tell if the object is entirely outside (-1),
 *	entirely inside (1) or in between (0).
 *
 **********************************************************************************
 */
static int
ToArea(Item	item,
       ZnBBox	*area,
       Tk_Uid	tag_uid,
       int	enclosed,
       ZnBool	report)
{
  ArcItem	arc = (ArcItem) item;
  WidgetInfo	*wi = item->wi;
  ZnPoint	*points;
  ZnPoint	pts[20]; /* Should be at least LINE_END_POINTS large */
  ZnPoint	center, tang;
  ZnBBox	t_area;
  int		num_points, result=-1, result2;
  ZnReal	lw = arc->line_width;
  ZnReal	rx, ry, angle, tmp;
  ZnBool	inside, new_inside;
  
  if (ISSET(arc->flags, USING_POLY_BIT) &&
      (ISSET(arc->flags, FILLED_BIT) || (arc->line_width))) {
    GetBezierPath(arc->render_shape, wi->work_pts);
    points = (ZnPoint *) ZnListArray(wi->work_pts);
    num_points = ZnListSize(wi->work_pts);

    if (ISSET(arc->flags, FILLED_BIT)) {
      result = PolygonInBBox(points, num_points, area, NULL);
      if (result == 0) {
	return 0;
      }
    }
    if (arc->line_width > 0) {
      result2 = PolylineInBBox(points, num_points, arc->line_width,
			       CapRound, JoinRound, area);
      if (ISCLEAR(arc->flags, FILLED_BIT)) {
	if (result2 == 0) {
	  return 0;
	}
	result = result2;
      }
      else if (result2 != result) {
	return 0;
      }
      if (ISSET(arc->flags, CLOSED_BIT) && ISSET(arc->flags, PIE_SLICE_BIT)) {
	pts[0] = points[num_points-1];
	pts[1] = points[0];
	if (PolylineInBBox(pts, 2, arc->line_width,
			   CapRound, JoinRound, area) != result) {
	  return 0;
	}
      }
      /*
       * Check line ends.
       */
      if (ISSET(arc->flags, FIRST_END_OK)) {
	GetLineEnd(&points[0], &points[1], arc->line_width, CapRound,
		   arc->first_end, pts);
	if (PolygonInBBox(pts, LINE_END_POINTS, area, NULL) != result) {
	  return 0;
	}
      }
      if (ISSET(arc->flags, LAST_END_OK)) {
	GetLineEnd(&points[num_points-1], &points[num_points-2], arc->line_width,
		   CapRound, arc->last_end, pts);
	if (PolygonInBBox(pts, LINE_END_POINTS, area, NULL) != result) {
	  return 0;
	}
      }
    }
    return result;
  }

  /*
   *******		********			**********
   * The rest of this code deal with non rotated arcs.           *
   * It has been stolen from tkCanvArc.c			 *
   *******		********			**********
   */
  /*
   * Transform both the arc and the rectangle so that the arc's oval
   * is centered on the origin.
   */
  center.x = (arc->orig.x + arc->corner.x)/2.0;
  center.y = (arc->orig.y + arc->corner.y)/2.0;
  t_area.orig.x = area->orig.x - center.x;
  t_area.orig.y = area->orig.y - center.y;
  t_area.corner.x = area->corner.x - center.x;
  t_area.corner.y = area->corner.y - center.y;
  rx = arc->corner.x - center.x + lw/2.0;
  ry = arc->corner.y - center.y + lw/2.0;

  /*
   * Find the extreme points of the arc and see whether these are all
   * inside the rectangle (in which case we're done), partly in and
   * partly out (in which case we're done), or all outside (in which
   * case we have more work to do).  The extreme points include the
   * following, which are checked in order:
   *
   * 1. The outside points of the arc, corresponding to start and
   *	  extent.
   * 2. The center of the arc (but only in pie-slice mode).
   * 3. The 12, 3, 6, and 9-o'clock positions (but only if the arc
   *    includes those angles).
   */
  points = pts;
  angle = DegreesToRadian(arc->start_angle);
  points->x = rx*cos(angle);
  points->y = ry*sin(angle);
  angle += DegreesToRadian(arc->angle_extent);
  points[1].x = rx*cos(angle);
  points[1].y = ry*sin(angle);
  num_points = 2;
  points += 2;

  if (ISSET(arc->flags, PIE_SLICE_BIT) && (arc->angle_extent < 180.0)) {
    points->x = 0.0;
    points->y = 0.0;
    num_points++;
    points++;
  }

  tmp = -arc->start_angle;
  if (tmp < 0) {
    tmp += 360.0;
  }
  if ((tmp < arc->angle_extent) || ((tmp-360) > arc->angle_extent)) {
    points->x = rx;
    points->y = 0.0;
    num_points++;
    points++;
  }
  tmp = 180.0 - arc->start_angle;
  if (tmp < 0) {
    tmp += 360.0;
  }
  if ((tmp < arc->angle_extent) || ((tmp-360) > arc->angle_extent)) {
    points->x = 0.0;
    points->y = ry;
    num_points++;
    points++;
  }
  tmp = 90.0 - arc->start_angle;
  if (tmp < 0) {
    tmp += 360.0;
  }
  if ((tmp < arc->angle_extent) || ((tmp-360) > arc->angle_extent)) {
    points->x = -rx;
    points->y = 0.0;
    num_points++;
    points++;
  }
  tmp = 270.0 - arc->start_angle;
  if (tmp < 0) {
    tmp += 360.0;
  }
  if ((tmp < arc->angle_extent) || ((tmp-360) > arc->angle_extent)) {
    points->x = 0.0;
    points->y = -ry;
    num_points++;
  }

  /*
   * Now that we've located the extreme points, loop through them all
   * to see which are inside the rectangle.
   */
  inside = PointInBBox(&t_area, pts->x, pts->y);
  for (points = pts+1; num_points > 1; points++, num_points--) {
    new_inside = PointInBBox(&t_area, points->x, points->y);
    if (new_inside != inside) {
      return 0;
    }
  }
  result = inside ? 1 : -1;
  
  /*
   * So far, oval appears to be outside rectangle, but can't yet tell
   * for sure.  Next, test each of the four sides of the rectangle
   * against the bounding region for the arc.  If any intersections
   * are found, then return "overlapping".  First, test against the
   * polygon(s) forming the sides of a chord or pie-slice.
   */
  if ((lw >= 1.0) && (ISSET(arc->flags, CLOSED_BIT))) {
    if (ISSET(arc->flags, PIE_SLICE_BIT)) {
      pts[0] = arc->center1;
      pts[1] = center;
      pts[2] = arc->center2;
      num_points = 3;
    }
    else {
      pts[0] = arc->center1;
      pts[1] = arc->center2;
      num_points = 2;
    }
    if (PolylineInBBox(pts, num_points, lw, CapRound, JoinRound, area) != result) {
      return 0;
    }
  }
  else if (ISSET(arc->flags, FILLED_BIT)) {
    if (ISSET(arc->flags, PIE_SLICE_BIT)) {
      if ((LineInBBox(&center, &arc->center1, area) != result) ||
	  (LineInBBox(&center, &arc->center2, area) != result)) {
	return 0;
      }
    }
    else {
      if (LineInBBox(&arc->center1, &arc->center2, area) != result) {
	return 0;
      }
    }
  }

  /*
   * Check line ends.
   */
  if (ISSET(arc->flags, FIRST_END_OK)) {
    Tangent(arc, True, &tang);
    GetLineEnd(&arc->center1, &tang, arc->line_width, CapRound,
	       arc->first_end, pts);
    if (PolygonInBBox(pts, LINE_END_POINTS, area, NULL) != result) {
      return 0;
    }
  }
  if (ISSET(arc->flags, LAST_END_OK)) {
    Tangent(arc, False, &tang);
    GetLineEnd(&arc->center2, &tang, arc->line_width, CapRound,
	       arc->last_end, pts);
    if (PolygonInBBox(pts, LINE_END_POINTS, area, NULL) != result) {
      return 0;
    }
  }
  if (result == 1) {
    return result;
  }
  
  /*
   * Next check for overlap between each of the four sides and the
   * outer perimiter of the arc.  If the arc isn't filled, then also
   * check the inner perimeter of the arc.
   */
  if (HorizLineToArc(t_area.orig.x, t_area.corner.x, t_area.orig.y,
		     rx, ry, arc->start_angle, arc->angle_extent) ||
      HorizLineToArc(t_area.orig.x, t_area.corner.x, t_area.corner.y,
		     rx, ry, arc->start_angle, arc->angle_extent) ||
      VertLineToArc(t_area.orig.x, t_area.orig.y, t_area.corner.y,
		       rx, ry, arc->start_angle, arc->angle_extent) ||
      VertLineToArc(t_area.corner.x, t_area.orig.y, t_area.corner.y,
		    rx, ry, arc->start_angle, arc->angle_extent)) {
    return 0;
  }
  if ((lw > 1.0) && ISCLEAR(arc->flags, FILLED_BIT)) {
    rx -= lw;
    ry -= lw;
    if (HorizLineToArc(t_area.orig.x, t_area.corner.x, t_area.orig.y,
		       rx, ry, arc->start_angle, arc->angle_extent) ||
	HorizLineToArc(t_area.orig.x, t_area.corner.x, t_area.corner.y,
		       rx, ry, arc->start_angle, arc->angle_extent) ||
	VertLineToArc(t_area.orig.x, t_area.orig.y, t_area.corner.y,
		      rx, ry, arc->start_angle, arc->angle_extent) ||
	VertLineToArc(t_area.corner.x, t_area.orig.y, t_area.corner.y,
		      rx, ry, arc->start_angle, arc->angle_extent)) {
      return 0;
    }
  }
  
  /*
   * The arc still appears to be totally disjoint from the rectangle,
   * but it's also possible that the rectangle is totally inside the arc.
   * Do one last check, which is to check one point of the rectangle
   * to see if it's inside the arc.  If it is, we've got overlap.  If
   * it isn't, the arc's really outside the rectangle.
   */
  if (Pick(item, &area->orig, ZN_NO_ITEM, 0, NULL, NULL) == 0.0) {
    return 0;
  }

  return -1;
}


/*
 **********************************************************************************
 *
 * Draw --
 *
 **********************************************************************************
 */
static void
Draw(Item	item)
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;
  XGCValues  	values;
  int		width=0, height=0;
  ZnPoint	*p=NULL;
  XPoint	*xp=NULL;
  int		num_points=0, i;
  
  if (ISSET(arc->flags, USING_POLY_BIT) &&
      (ISSET(arc->flags, FILLED_BIT) || (arc->line_width))) {
    GetBezierPath(arc->render_shape, wi->work_pts);
    p = (ZnPoint *) ZnListArray(wi->work_pts);
    num_points = ZnListSize(wi->work_pts);
    ZnListAssertSize(wi->work_xpts, num_points);
    xp = (XPoint *) ZnListArray(wi->work_xpts);
    for (i = 0; i < num_points; i++, p++) {
      xp[i].x = (short) p->x;
      xp[i].y = (short) p->y;
    }
    p = (ZnPoint *) ZnListArray(wi->work_pts);
  }
  else {
    width = arc->corner.x - arc->orig.x;
    height = arc->corner.y - arc->orig.y;
  }
  
  /* Fill if requested */
  if (ISSET(arc->flags, FILLED_BIT)) {
    if (arc->grad_geom) {
      ZnPoly	poly;
      POLY_CONTOUR1(&poly, p, num_points);
      DrawPolygonGradient(wi, arc->grad_geom, arc->fill_color, &poly,
			  &item->item_bounding_box);
    }
    else {
      values.foreground = ZnPixel(ZnColorGradientMidColor(wi->win, arc->fill_color));
      values.arc_mode = ISSET(arc->flags, PIE_SLICE_BIT) ? ArcPieSlice : ArcChord;
      if (arc->tile != ZnUnspecifiedImage) { /* Fill Tiled */
	Pixmap pmap = GetImagePixmap(wi->win, arc->tile_name, arc->tile, NULL);
	values.fill_style = FillTiled;
	values.tile = pmap;
	values.ts_x_origin = (int) item->item_bounding_box.orig.x;
	values.ts_y_origin = (int) item->item_bounding_box.orig.y;
	XChangeGC(wi->dpy, wi->gc,
		  GCTileStipXOrigin|GCTileStipYOrigin|GCFillStyle|GCTile|GCArcMode,
		  &values);
      }
      else if (arc->fill_pattern != ZnUnspecifiedPattern) { /* Fill stippled */
	values.fill_style = FillStippled;
	values.stipple = arc->fill_pattern;
	values.ts_x_origin = (int) item->item_bounding_box.orig.x;
	values.ts_y_origin = (int) item->item_bounding_box.orig.y;
	XChangeGC(wi->dpy, wi->gc,
		  GCTileStipXOrigin|GCTileStipYOrigin|GCFillStyle|GCStipple|GCForeground|GCArcMode,
		  &values);
      }
      else { /* Fill solid */
	values.fill_style = FillSolid;
	XChangeGC(wi->dpy, wi->gc, GCForeground|GCFillStyle|GCArcMode, &values);
      }
      if (ISSET(arc->flags, USING_POLY_BIT)) {
	XFillPolygon(wi->dpy, wi->draw_buffer, wi->gc,
		     xp, num_points, Convex, CoordModeOrigin);
      }
      else {
	XFillArc(wi->dpy, wi->draw_buffer, wi->gc,
		 arc->orig.x, arc->orig.y, width, height,
		 -arc->start_angle*64, -arc->angle_extent*64);
      }
    }
  }

  /*
   * Draw the arc.
   */
  if (arc->line_width) {
    ZnPoint  end_points[LINE_END_POINTS];
    XPoint      xap[LINE_END_POINTS];
    ZnPoint	tang;
      
    SetLineStyle(wi->dpy, wi->gc, arc->line_style);
    values.foreground = ZnPixel(arc->line_color);
    values.line_width = (arc->line_width == 1) ? 0 : arc->line_width;
    values.cap_style = CapRound;
    values.join_style = JoinRound;
    if (arc->line_pattern == ZnUnspecifiedPattern) {
      values.fill_style = FillSolid;
      XChangeGC(wi->dpy, wi->gc,
		GCFillStyle|GCLineWidth|GCCapStyle|GCJoinStyle|GCForeground, &values);
    }
    else {
      values.fill_style = FillStippled;
      values.stipple = arc->line_pattern;
      XChangeGC(wi->dpy, wi->gc,
		GCFillStyle|GCStipple|GCLineWidth|GCCapStyle|GCJoinStyle|GCForeground,
		&values);
    }
    if (ISSET(arc->flags, USING_POLY_BIT)) {
      XDrawLines(wi->dpy, wi->draw_buffer, wi->gc,
		 xp, num_points, CoordModeOrigin);
      if (ISSET(arc->flags, CLOSED_BIT) && ISSET(arc->flags, PIE_SLICE_BIT)) {
	XDrawLine(wi->dpy, wi->draw_buffer, wi->gc,
		  xp[num_points-1].x, xp[num_points-1].y,
		  xp[0].x, xp[0].y);
      }
      if (ISSET(arc->flags, FIRST_END_OK)) {
	p = (ZnPoint *) ZnListArray(arc->render_shape);
	GetLineEnd(p, p+1, arc->line_width, CapRound,
		   arc->first_end, end_points);
	for (i = 0; i < LINE_END_POINTS; i++) {
	  xap[i].x = end_points[i].x;
	  xap[i].y = end_points[i].y;
	}
	XFillPolygon(wi->dpy, wi->draw_buffer, wi->gc, xap, LINE_END_POINTS,
		     Nonconvex, CoordModeOrigin);
      }
      if (ISSET(arc->flags, LAST_END_OK)) {
	p = (ZnPoint *) ZnListArray(arc->render_shape);
	num_points = ZnListSize(arc->render_shape);
	GetLineEnd(&p[num_points-1], &p[num_points-2], arc->line_width,
		   CapRound, arc->last_end, end_points);
	for (i = 0; i < LINE_END_POINTS; i++) {
	  xap[i].x = end_points[i].x;
	  xap[i].y = end_points[i].y;
	}
	XFillPolygon(wi->dpy, wi->draw_buffer, wi->gc, xap, LINE_END_POINTS,
		     Nonconvex, CoordModeOrigin);
      }
    }
    else {
      XDrawArc(wi->dpy, wi->draw_buffer, wi->gc,
	       arc->orig.x, arc->orig.y, width, height,
	       -arc->start_angle*64, -arc->angle_extent*64);
      /*
       * If the outline is closed, draw the closure.
       */
      if (ISSET(arc->flags, CLOSED_BIT)) {
	if (ISSET(arc->flags, PIE_SLICE_BIT)) {
	  XPoint	points[3];
	  
	  points[0].x = arc->center1.x;
	  points[0].y = arc->center1.y;
	  points[1].x = (arc->corner.x + arc->orig.x) / 2;
	  points[1].y = (arc->corner.y + arc->orig.y) / 2;
	  points[2].x = arc->center2.x;
	  points[2].y = arc->center2.y;
	  XDrawLines(wi->dpy, wi->draw_buffer, wi->gc, points, 3, CoordModeOrigin);
	}
	else {
	  XDrawLine(wi->dpy, wi->draw_buffer, wi->gc,
		    arc->center1.x, arc->center1.y, arc->center2.x, arc->center2.y);
	}
      }
      if (ISSET(arc->flags, FIRST_END_OK)) {
	Tangent(arc, True, &tang);
	GetLineEnd(&arc->center1, &tang, arc->line_width, CapRound,
		   arc->first_end, end_points);
	for (i = 0; i < LINE_END_POINTS; i++) {
	  xap[i].x = end_points[i].x;
	  xap[i].y = end_points[i].y;
	}
	XFillPolygon(wi->dpy, wi->draw_buffer, wi->gc, xap, LINE_END_POINTS,
		     Nonconvex, CoordModeOrigin);
      }
      if (ISSET(arc->flags, LAST_END_OK)) {
	Tangent(arc, False, &tang);
	GetLineEnd(&arc->center2, &tang, arc->line_width, CapRound,
		   arc->last_end, end_points);
	for (i = 0; i < LINE_END_POINTS; i++) {
	  xap[i].x = end_points[i].x;
	  xap[i].y = end_points[i].y;
	}
	XFillPolygon(wi->dpy, wi->draw_buffer, wi->gc, xap, LINE_END_POINTS,
		     Nonconvex, CoordModeOrigin);
      }
    }
  }
}


/*
 **********************************************************************************
 *
 * Render --
 *
 **********************************************************************************
 */
static void
Render(Item	item)
{
  /*WidgetInfo	*wi = item->wi;
    ArcItem	arc = (ArcItem) item;*/

}


/*
 **********************************************************************************
 *
 * IsSensitive --
 *
 **********************************************************************************
 */
static ZnBool
IsSensitive(Item	item,
	    int		item_part)
{
  return (ISSET(item->flags, SENSITIVE_BIT) &&
	  item->parent->class->IsSensitive(item->parent, ZN_NO_PART));
}


/*
 **********************************************************************************
 *
 * Pick --
 *
 **********************************************************************************
 */
static double
Pick(Item	item,
     ZnPoint	*p,
     Item	start_item,
     int	aperture,
     Item	*a_item,
     int	*a_part)
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;
  double	dist = 1e40, new_dist;
  ZnBool	point_in_angle, filled, closed;
  ZnBool	in_triangle, acute_angle;
  ZnPoint	p1, center, tang;
  ZnPoint	*points;
  ZnPoint	end_points[LINE_END_POINTS];
  int		num_points;
  int		width, height;
  ZnDim		lw = arc->line_width;
  
  if (ISSET(arc->flags, USING_POLY_BIT) &&
      (ISSET(arc->flags, FILLED_BIT) || (arc->line_width))) {
    GetBezierPath(arc->render_shape, wi->work_pts);
    points = (ZnPoint *) ZnListArray(wi->work_pts);
    num_points = ZnListSize(wi->work_pts);

    if (ISSET(arc->flags, FILLED_BIT)) {
      dist = PolygonToPointDist(points, num_points, p);
      if (dist <= 0.0) {
	return 0.0;
      }
    }
    if (arc->line_width > 0) {
      new_dist = PolylineToPointDist(points, num_points, arc->line_width,
				     CapRound, JoinRound, p);
      if (new_dist < dist) {
	dist = new_dist;
      }
      if (ISSET(arc->flags, CLOSED_BIT) && ISSET(arc->flags, PIE_SLICE_BIT)) {
	new_dist = LineToPointDist(&points[num_points-1], &points[0], p);
	if (new_dist < dist) {
	  dist = new_dist;
	}
      }
      if (dist <= 0.0) {
	return 0.0;
      }
    }
    /*
     * Check line ends.
     */
    if (ISSET(arc->flags, FIRST_END_OK)) {
      GetLineEnd(&points[0], &points[1], arc->line_width, CapRound,
		 arc->first_end, end_points);
      new_dist = PolygonToPointDist(end_points, LINE_END_POINTS, p);
      if (new_dist < dist) {
	dist = new_dist;
      }
      if (dist <= 0.0) {
	return 0.0;
      }
    }
    if (ISSET(arc->flags, LAST_END_OK)) {
      GetLineEnd(&points[num_points-1], &points[num_points-2], arc->line_width,
		 CapRound, arc->last_end, end_points);
      new_dist = PolygonToPointDist(end_points, LINE_END_POINTS, p);
      if (new_dist < dist) {
	dist = new_dist;
      }
      if (dist <= 0.0) {
	return 0.0;
      }
    }
    return dist;
  }

  /*
   *******		********			**********
   * The rest of this code deal with non rotated or relief arcs. *
   *******		********			**********
   */
  center.x = (arc->corner.x + arc->orig.x) / 2;
  center.y = (arc->corner.y + arc->orig.y) / 2;
  width = arc->corner.x - arc->orig.x;
  height = arc->corner.y - arc->orig.y;
  
  /*
   * Let see if the point is in the angular range. First
   * transform the coordinates so that the oval is circular.
   */
  p1.y = (p->y - center.y) / height;
  p1.x = (p->x - center.x) / width;
  point_in_angle = PointInAngle(arc->start_angle, arc->angle_extent, &p1);

  /*
   * Now try to compute the distance dealing with the
   * many possible configurations.
   */
  filled = !ISCLEAR(arc->flags, FILLED_BIT);
  closed = !ISCLEAR(arc->flags, CLOSED_BIT);

  /*
   * First the case of an arc not filled, not closed. We suppose
   * here that the outline is drawn since we cannot get here without
   * filling or outlining.
   */
  if (!filled && !closed) {
    if (point_in_angle) {
      dist = OvalToPointDist(&center, width, height, lw, p);
      if (dist < 0.0) {
	dist = -dist;
      }
    }
    else {
      dist = hypot((p->x - arc->center1.x), (p->y - arc->center1.y));
    }
    new_dist = hypot((p->x - arc->center2.x), (p->y - arc->center2.y));
    if (new_dist < dist) {
      dist = new_dist;
    }
    /* Take into account CapRounded path. */
    if (lw > 1) {
      dist -= lw/2;
      if (dist < 0.0) {
	dist = 0.0;
      }
    }
    if (dist == 0.0) {
      return 0.0;
    }

    /*
     * Check line ends.
     */
    if (ISSET(arc->flags, FIRST_END_OK)) {
      Tangent(arc, True, &tang);
      GetLineEnd(&arc->center1, &tang, arc->line_width, CapRound,
		 arc->first_end, end_points);
      new_dist = PolygonToPointDist(end_points, LINE_END_POINTS, p);
      if (new_dist < dist) {
	dist = new_dist;
      }
      if (dist <= 0.0) {
	return 0.0;
      }
    }
    if (ISSET(arc->flags, LAST_END_OK)) {
      Tangent(arc, False, &tang);
      GetLineEnd(&arc->center2, &tang, arc->line_width,
		 CapRound, arc->last_end, end_points);
      new_dist = PolygonToPointDist(end_points, LINE_END_POINTS, p);
      if (new_dist < dist) {
	dist = new_dist;
      }
      if (dist <= 0.0) {
	return 0.0;
      }
    }
    return dist;
  }
  
  /*
   * Try to deal with filled and/or outline-closed arcs (not having full
   * angular extent).
   */
  if (ISSET(arc->flags, PIE_SLICE_BIT)) {
    dist = LineToPointDist(&center, &arc->center1, p);
    new_dist = LineToPointDist(&center, &arc->center2, p);
    if (new_dist < dist) {
      dist = new_dist;
    }
    if (arc->line_width > 1) {
      if (closed) {
	dist -= arc->line_width/2;
      }
      /*
       * The arc outline is CapRounded so if it is not
       * full extent, includes the caps.
       */
      else {
	new_dist = hypot(p->x - arc->center1.x, p->y - arc->center1.y) - lw/2;
	if (new_dist < dist) {
	  dist = new_dist;
	}
	new_dist = hypot(p->x - arc->center2.x, p->y - arc->center2.y) - lw/2;
	if (new_dist < dist) {
	  dist = new_dist;
	}
      }
    }
    if (dist <= 0.0) {
      return 0.0;
    }
    if (point_in_angle) {
      new_dist = OvalToPointDist(&center, width, height, lw, p);
      if (new_dist < dist) {
	dist = new_dist;
      }
      if (dist < 0.0) {
	dist = filled ? 0.0 : -dist;
      }
    }
    return dist;
  }

  /*
   * This is a chord closed oval.
   */    
  dist = LineToPointDist(&arc->center1, &arc->center2, p);
  if (arc->line_width > 1) {
    if (closed) {
      dist -= arc->line_width/2;
    }
    /*
     * The arc outline is CapRounded so if it is not
     * full extent, includes the caps.
     */
    else {
      new_dist = hypot(p->x - arc->center1.x, p->y - arc->center1.y) - lw/2;
      if (new_dist < dist) {
	dist = new_dist;
      }
      new_dist = hypot(p->x - arc->center2.x, p->y - arc->center2.y) - lw/2;
      if (new_dist < dist) {
	dist = new_dist;
      }
    }
  }
  if (dist <= 0.0) {
    return 0.0;
  }
  
  /*
   * Need to check the point against the triangle formed
   * by the difference between Chord mode and PieSlice mode.
   * This triangle needs to be included if extend is more than
   * 180 degrees and excluded otherwise. We try to see if
   * the center of the arc and the point are both on the same
   * side of the chord. If they are, the point is in the triangle
   */
  if (arc->center1.x == arc->center2.x) {
    in_triangle = ((center.x <= arc->center1.x) && (p->x <= arc->center1.x)) ||
      ((center.x > arc->center1.x) && (p->x > arc->center1.x));
  }
  else {
    double	a, b;
    
    a = ((double) (arc->center2.y - arc->center1.y)) /
      ((double) (arc->center2.x - arc->center1.x));
    b = arc->center1.y - a*arc->center1.x;
    in_triangle = (((a*center.x + b - center.y) >= 0.0) ==
		   ((a*p->x + b - p->y) >= 0.0));
  }
  
  acute_angle = ((arc->angle_extent > -180) && (arc->angle_extent < 180));
  if (!point_in_angle && !acute_angle && filled && in_triangle) {
    return 0.0;
  }
  
  if (point_in_angle && (!acute_angle || !in_triangle)) {
    new_dist = OvalToPointDist(&center, width, height, lw, p);
    if (new_dist < dist) {
      dist = new_dist;
    }
    if (dist < 0.0) {
      dist = filled ? 0.0 : -dist;
    }
    if (dist == 0.0) {
      return 0.0;
    }
  }

  return dist;
}


/*
 **********************************************************************************
 *
 * GetClipVertices --
 *	Get the clipping shape.
 *
 **********************************************************************************
 */
static ZnBool
GetClipVertices(Item	item,
		ZnPoly	*poly)
{
  WidgetInfo	*wi = item->wi;
  ArcItem	arc = (ArcItem) item;
  ZnReal	ox, oy, width_2, height_2;
  int		i, num_p;
  ZnPoint	*p_list;
  
  if (ISCLEAR(arc->flags, USING_POLY_BIT)) {
    if (!arc->render_shape) {
      arc->render_shape = ZnListNew(4, sizeof(ZnPoint));
    }
    GetArcPath(DegreesToRadian(arc->start_angle),
	       DegreesToRadian(arc->start_angle+arc->angle_extent),
	       (ISCLEAR(arc->flags, CLOSED_BIT) ? 0 :
		ISCLEAR(arc->flags, PIE_SLICE_BIT) ? 1 : 2), arc->render_shape);
    ox = (arc->corner.x + arc->orig.x) / 2.0;
    oy = (arc->corner.y + arc->orig.y) / 2.0;
    width_2 = (arc->corner.x - arc->orig.x) / 2.0;
    height_2 = (arc->corner.y - arc->orig.y) / 2.0;
    num_p = ZnListSize(arc->render_shape);
    p_list = (ZnPoint *) ZnListArray(arc->render_shape);
    for (i = 0; i < num_p; i++, p_list++) {
      p_list->x = ox + p_list->x*width_2;
      p_list->y = oy + p_list->y*height_2;
    }
    SET(arc->flags, USING_POLY_BIT);
  }
  GetBezierPath(arc->render_shape, wi->work_pts);

  POLY_CONTOUR1(poly, (ZnPoint *) ZnListArray(wi->work_pts),
		ZnListSize(wi->work_pts));

  return False;
}


/*
 **********************************************************************************
 *
 * Coords --
 *	Return or edit the item vertices.
 *
 **********************************************************************************
 */
static int
Coords(Item	item,
       int	contour,
       int	index,
       int	cmd,
       ZnPoint	**pts,
       int	*num_pts)
{
  ArcItem	arc = (ArcItem) item;

  if ((cmd == COORDS_ADD) || (cmd == COORDS_ADD_LAST) || (cmd == COORDS_REMOVE)) {
    Tcl_AppendResult(item->wi->interp,
		     " arcs can't add or remove vertices", NULL);
    return ZN_ERROR;
  }
  else if (cmd == COORDS_REPLACE_ALL) {
    if (*num_pts != 2) {
      Tcl_AppendResult(item->wi->interp,
		       " coords command need 2 points on arcs", NULL);
      return ZN_ERROR;
    }
    arc->coords[0] = (*pts)[0];
    arc->coords[1] = (*pts)[1];
    ITEM.Invalidate(item, ZN_COORDS_FLAG);
  }
  else if (cmd == COORDS_REPLACE) {
    if (*num_pts < 1) {
      Tcl_AppendResult(item->wi->interp,
		       " coords command need at least 1 point", NULL);
      return ZN_ERROR;
    }
    if (index < 0) {
      index += 2;
    }
    if ((index < 0) || (index > 1)) {
    range_err:
      Tcl_AppendResult(item->wi->interp,
		       " incorrect coord index, should be between -2 and 1", NULL);
      return ZN_ERROR;
    }
    arc->coords[index] = (*pts)[0];
    ITEM.Invalidate(item, ZN_COORDS_FLAG);
  }
  else if (cmd == COORDS_READ_ALL) {
    *num_pts = 2;
    *pts = arc->coords;
  }
  else if (cmd == COORDS_READ) {
    if (index < 0) {
      index += 2;
    }
    if ((index < 0) || (index > 1)) {
      goto range_err;
    }
    *num_pts = 1;
    *pts = &arc->coords[index];
  }

  return ZN_OK;
}


/*
 **********************************************************************************
 *
 * PostScript --
 *
 **********************************************************************************
 */
static void
PostScript(Item			item,
	   PostScriptInfo	ps_info)
{
}


/*
 **********************************************************************************
 *
 * Exported functions struct --
 *
 **********************************************************************************
 */
static ItemClassStruct ARC_ITEM_CLASS = {
  sizeof(ArcItemStruct),
  False,		/* has_fields */
  0,			/* num_parts */
  False,		/* has_anchors */
  "arc",
  arc_attrs,
  Init,
  Clone,
  Destroy,
  Configure,
  Query,
  NULL,			/* GetFieldSet */
  NULL,			/* GetAnchor */
  GetClipVertices,
  Coords,
  NULL,			/* InsertChars */
  NULL,			/* DeleteChars */
  NULL,			/* Cursor */
  NULL,			/* Index */
  NULL,			/* Part */
  NULL,			/* Selection */
  NULL,			/* Contour */
  ComputeCoordinates,
  ToArea,
  Draw,
  Render,
  IsSensitive,
  Pick,
  NULL,			/* PickVertex */
  PostScript
};

ZnItemClassId ZnArc = (ZnItemClassId) &ARC_ITEM_CLASS;