gimp/app/tools/bezier_select.c

/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "appenv.h"
#include "draw_core.h"
#include "edit_selection.h"
#include "errors.h"
#include "gdisplay.h"
#include "gimage_mask.h"
#include "rect_select.h"
#include "interface.h"
#include "actionarea.h"
#include "bezier_select.h"
#include "bezier_selectP.h"
#include "paths_dialog.h"

#include "libgimp/gimpintl.h"

/* Bezier extensions made by Raphael FRANCOIS (fraph@ibm.net)

  BEZIER_EXTENDS VER 1.0 

  - work as the cut/copy/paste named functions.
  - allow to add/remove/replace bezier curves
  - allow to modify the control/anchor points even if the selection is made
  - allow to add/remove control/anchor points on a curve
  - allow to update a previous saved curve

  - cannot operate on open or multiple curves simultaneously
*/

#define BEZIER_DRAW_CURVE   1
#define BEZIER_DRAW_CURRENT 2
#define BEZIER_DRAW_HANDLES 4
#define BEZIER_DRAW_ALL     (BEZIER_DRAW_CURVE | BEZIER_DRAW_HANDLES)

#define BEZIER_WIDTH     8
#define BEZIER_HALFWIDTH 4


#define SUPERSAMPLE   3
#define SUPERSAMPLE2  9

#define NO  0
#define YES 1

#define ROUND(x)  ((int) ((x) + 0.5))

/* bezier select type definitions */

typedef double BezierMatrix[4][4];

/* The named paste dialog */
typedef struct _PasteNamedDlg PasteNamedDlg;

struct _PasteNamedDlg
{
  GtkWidget   *shell;
  GtkWidget   *list;
  GDisplay    *gdisp; 
};

/* The named buffer structure... */
typedef struct _named_buffer BezierNamedBuffer;

struct _named_buffer
{
  BezierSelect *sel;
  char *        name;
};

typedef struct {
  gdouble *stroke_points;
  gint	   num_stroke_points;	/* num of valid points */
  gint	   len_stroke_points;	/* allocated length */
} BezierRenderPnts;

typedef struct {
  gboolean firstpnt;
  gdouble  curdist;
  gdouble  dist;
  gdouble  *gradient;
  gint     *x;
  gint     *y;
  gdouble  lastx;
  gdouble  lasty;
  gboolean found;
} BezierDistance;

static void  bezier_select_button_press    (Tool *, GdkEventButton *, gpointer);
static void  bezier_select_button_release  (Tool *, GdkEventButton *, gpointer);
static void  bezier_select_motion          (Tool *, GdkEventMotion *, gpointer);
static void  bezier_select_control         (Tool *, int, gpointer);
static void  bezier_select_draw            (Tool *);

static void  bezier_offset_point           (BezierPoint *, int, int);
static int   bezier_check_point            (BezierPoint *, int, int, int);
static void  bezier_draw_handles           (BezierSelect *);
static void  bezier_draw_current           (BezierSelect *);
static void  bezier_draw_point             (BezierSelect *, BezierPoint *, int);
static void  bezier_draw_line              (BezierSelect *, BezierPoint *, BezierPoint *);
static void  bezier_draw_segment           (BezierSelect *, BezierPoint *, int, int, BezierPointsFunc,gpointer);
static void  bezier_draw_segment_points    (BezierSelect *, GdkPoint *, int, gpointer);
static void  bezier_compose                (BezierMatrix, BezierMatrix, BezierMatrix);

static void  bezier_convert                (BezierSelect *, GDisplay *, int, int);
static void  bezier_convert_points         (BezierSelect *, GdkPoint *, int, gpointer);
static void  bezier_convert_line           (GSList **, int, int, int, int);
static GSList * bezier_insert_in_list      (GSList *, int);

static int   test_add_point_on_segment     (BezierSelect *, BezierPoint *, int, int, int, int, int);
static void  bezier_to_sel_internal        (BezierSelect *, Tool *, GDisplay *, gint, gint);
static void  bezier_stack_points	   (BezierSelect *, GdkPoint *, int, gpointer);
static gboolean stroke_interpolatable    (int, int, int, int, gdouble);
static void bezier_stack_points_aux      (GdkPoint *, int, int, gdouble, BezierRenderPnts *);

static BezierMatrix basis =
{
  { -1,  3, -3,  1 },
  {  3, -6,  3,  0 },
  { -3,  3,  0,  0 },
  {  1,  0,  0,  0 },
};

/*
static BezierMatrix basis =
{
  { -1/6.0,  3/6.0, -3/6.0,  1/6.0 },
  {  3/6.0, -6/6.0,  3/6.0,  0 },
  { -3/6.0,  0,  3/6.0,  0 },
  {  1/6.0,  4/6.0,  1,  0 },
};
*/

/*  The named buffer list  */
GSList *bezier_named_buffers = NULL;
 
static SelectionOptions *bezier_options = NULL;

/* Global Static Variable to maintain informations about rhe "contexte" */
static BezierSelect * curSel;
static Tool * curTool;
static GDisplay * curGdisp;
static DrawCore * curCore;
static int ModeEdit = EXTEND_NEW;


static void
bezier_select_reset_options ()
{
  reset_selection_options (bezier_options);
}

Tool*
tools_new_bezier_select ()
{
  Tool * tool;
  BezierSelect * bezier_sel;

  /*  The tool options  */
  if (!bezier_options)
    bezier_options = create_selection_options (BEZIER_SELECT,
					       bezier_select_reset_options);

  tool = g_malloc (sizeof (Tool));

  bezier_sel = g_malloc (sizeof (BezierSelect));

  bezier_sel->num_points = 0;
  bezier_sel->mask = NULL;
  bezier_sel->core = draw_core_new (bezier_select_draw);
  bezier_select_reset (bezier_sel);

  tool->type = BEZIER_SELECT;
  tool->state = INACTIVE;
  tool->scroll_lock = 1;   /*  Do not allow scrolling  */
  tool->auto_snap_to = TRUE;
  tool->private = (void *) bezier_sel;
  tool->button_press_func = bezier_select_button_press;
  tool->button_release_func = bezier_select_button_release;
  tool->motion_func = bezier_select_motion;
  tool->arrow_keys_func = standard_arrow_keys_func;
  tool->cursor_update_func = rect_select_cursor_update;
  tool->control_func = bezier_select_control;
  tool->preserve = FALSE;

  curCore = bezier_sel->core;
  curSel = bezier_sel;
  curTool = tool;

  paths_new_bezier_select_tool();

  return tool;
}

void
tools_free_bezier_select (Tool *tool)
{
  BezierSelect * bezier_sel;

  bezier_sel = tool->private;

  if (tool->state == ACTIVE)
    draw_core_stop (bezier_sel->core, tool);
  draw_core_free (bezier_sel->core);

  bezier_select_reset (bezier_sel);

  g_free (bezier_sel);
}

int
bezier_select_load (void        *gdisp_ptr,
		    BezierPoint *pts,
		    int          num_pts,
		    int          closed)
{
  GDisplay * gdisp;
  Tool * tool;
  BezierSelect * bezier_sel;

  gdisp = (GDisplay *) gdisp_ptr;

  /*  select the bezier tool  */
  gtk_widget_activate (tool_info[BEZIER_SELECT].tool_widget);
  tool = active_tool;
  tool->state = ACTIVE;
  tool->gdisp_ptr = gdisp_ptr;
  bezier_sel = (BezierSelect *) tool->private;

  bezier_sel->points = pts;
  bezier_sel->last_point = pts->prev;
  bezier_sel->num_points = num_pts;
  bezier_sel->closed = closed;
  bezier_sel->state = BEZIER_EDIT;
  bezier_sel->draw = BEZIER_DRAW_ALL;

  bezier_convert (bezier_sel, tool->gdisp_ptr, SUBDIVIDE, NO);

  draw_core_start (bezier_sel->core, gdisp->canvas->window, tool);

  return 1;
}

void
bezier_draw_curve (BezierSelect    *bezier_sel,
		   BezierPointsFunc func, 
		   gint             coord,
		   gpointer         udata)
{
  BezierPoint * points;
  BezierPoint * start_pt;
  int num_points;

  points = bezier_sel->points;

  if (bezier_sel->closed)
    {
      start_pt = bezier_sel->points;

      do {
	bezier_draw_segment (bezier_sel, points,
			     SUBDIVIDE, coord,
			     func,
			     udata);

	points = points->next;
	points = points->next;
	points = points->next;
      } while (points != start_pt);
    }
  else
    {
      num_points = bezier_sel->num_points;

      while (num_points >= 4)
	{
	  bezier_draw_segment (bezier_sel, points,
			       SUBDIVIDE, coord,
			       func,
			       udata);

	  points = points->next;
	  points = points->next;
	  points = points->next;
	  num_points -= 3;
	}
    }
}

void
bezier_select_reset (BezierSelect *bezier_sel)
{
  BezierPoint * points;
  BezierPoint * start_pt;
  BezierPoint * temp_pt;

  if (bezier_sel->num_points > 0)
    {
      points = bezier_sel->points;
      start_pt = (bezier_sel->closed) ? (bezier_sel->points) : (NULL);

      do {
	temp_pt = points;
	points = points->next;

	g_free (temp_pt);
      } while (points != start_pt);
    }

  if (bezier_sel->mask)
    channel_delete (bezier_sel->mask);

  bezier_sel->state = BEZIER_START;    /* we are starting the curve */
  bezier_sel->draw = BEZIER_DRAW_ALL;  /* draw everything by default */
  bezier_sel->closed = 0;              /* the curve is initally open */
  bezier_sel->points = NULL;           /* initially there are no points */
  bezier_sel->cur_anchor = NULL;
  bezier_sel->cur_control = NULL;
  bezier_sel->last_point = NULL;
  bezier_sel->num_points = 0;          /* intially there are no points */
  bezier_sel->mask = NULL;             /* empty mask */
  bezier_sel->scanlines = NULL;
}

static gint
bezier_edit_point_on_curve(int           x,
			   int           y,
			   int           halfwidth,
			   GDisplay     *gdisp,
			   BezierSelect *bezier_sel,
			   Tool         *tool)
{
  gint grab_pointer = 0;
  BezierPoint  *points = bezier_sel->points;
  BezierPoint  *start_pt = bezier_sel->points;

  /* find if the button press occurred on a point */
  do {
    if (bezier_check_point (points, x, y, halfwidth))
      {
	  BezierPoint *finded=points;
	  BezierPoint *start_op; 
	  BezierPoint *end_op; 
	  
	  if (ModeEdit== EXTEND_REMOVE)
	    {
	      if (bezier_sel->num_points <= 7)
		{
		  /* If we've got less then 7 points ie: 2 anchors points 4 controls 
		     Then the curve is minimal closed curve.
		     I've decided to not operate on this kind of curve because it    
		     implies opening the curve and change some drawing states        
		     Removing 1 point of curve that contains 2 point is something    
		     similare to reconstruct the curve !!!
		  */
		  goto end;
		}
	      
	      bezier_sel->draw = BEZIER_DRAW_CURVE; 
	      draw_core_resume (bezier_sel->core, tool);
	      bezier_sel->draw = 0;
	      
	      draw_core_stop ( bezier_sel->core, tool );

	      if(!bezier_sel->closed && 
		 (finded == bezier_sel->points || finded == bezier_sel->points->next))
		{
		  /* This is the first point on the curve */
		  /* FIXME printf("Del first point\n"); */
		}
	      else if(!bezier_sel->closed && 
		      (finded == bezier_sel->last_point ||
		       finded == bezier_sel->last_point->prev || 
		       finded == bezier_sel->last_point->prev->prev))
		{
		  /* This is the last point on the curve */
		  /* FIXME printf("Del last point\n"); */
		}
	      else
		{
		  if ( finded->type == BEZIER_CONTROL )
		    {
		      if (finded->next->type == BEZIER_CONTROL)
			finded = finded->prev;
		      else
			finded = finded->next;
		    }
		  
		  start_op = finded->prev->prev;
		  end_op = finded->next->next;
		  
		  start_op->next = end_op;
		  end_op->prev = start_op;
		  
		  if ( (bezier_sel->last_point == finded) || 
		       (bezier_sel->last_point == finded->next) || 
		       (bezier_sel->last_point  == finded->prev))
		    {
		      bezier_sel->last_point = start_op->prev;
		      bezier_sel->points = start_op->prev;
		    }
		  
		  bezier_sel->num_points -= 3;
		  
		  g_free( finded->prev );
		  g_free( finded->next );
		  g_free( finded );
		  /* Clear current anchor and control */
		  bezier_sel->cur_anchor = NULL;
		  bezier_sel->cur_control = NULL;
		}
		  
	      bezier_sel->draw = BEZIER_DRAW_CURVE;       
	      draw_core_start (bezier_sel->core, gdisp->canvas->window, tool);
	    end:
	      bezier_sel->draw = BEZIER_DRAW_ALL; 
	      
	      draw_core_pause( bezier_sel->core, tool);               
	      draw_core_resume( bezier_sel->core, tool);
	    }
	  else
	    {
	      /* set the current anchor and control points */
	      switch (points->type)
		{
		case BEZIER_ANCHOR:
		  bezier_sel->cur_anchor = points;
		  bezier_sel->cur_control = bezier_sel->cur_anchor->next;
		  break;
		case BEZIER_CONTROL:
		  bezier_sel->cur_control = points;
		  if (bezier_sel->cur_control->next->type == BEZIER_ANCHOR)
		    bezier_sel->cur_anchor = bezier_sel->cur_control->next;
		  else
		    bezier_sel->cur_anchor = bezier_sel->cur_control->prev;
		  break;
		}
	    }
	  grab_pointer = 1;
	  break;
	}
	
	points = points->next;
      } while (points != start_pt && points);

  return grab_pointer;
}

static gint
bezier_add_point_on_segment(int           x,
			    int           y,
			    int           halfwidth,
			    GDisplay     *gdisp,
			    BezierSelect *bezier_sel,
			    Tool         *tool)
{
  BezierPoint  *points = bezier_sel->points;
  BezierPoint  *start_pt = bezier_sel->points;

  do {
    if (test_add_point_on_segment (bezier_sel,       
				   points,
				   SUBDIVIDE, 
				   IMAGE_COORDS,
				   x, y,
				   halfwidth))
      {
	bezier_sel->draw = BEZIER_DRAW_CURVE; 
	draw_core_resume (bezier_sel->core, tool);
	bezier_sel->draw = 0;
	draw_core_stop ( bezier_sel->core, tool );
	
	bezier_sel->draw = BEZIER_DRAW_CURVE;
	draw_core_start (bezier_sel->core, gdisp->canvas->window, tool);
	
	bezier_sel->draw = BEZIER_DRAW_ALL; 
	
	draw_core_pause( bezier_sel->core, tool);               
	draw_core_resume( bezier_sel->core, tool);
	
	return 1;
      }

    points = points->next;

    if(!points)
      return 0;

    points = points->next;

    if(!points)
      return 0;

    points = points->next;
  } while (points != start_pt && points);

  return 0;
}

static void
bezier_select_button_press (Tool           *tool,
			    GdkEventButton *bevent,
			    gpointer        gdisp_ptr)
{
  GDisplay *gdisp;
  BezierSelect *bezier_sel;
  BezierPoint *points;
  BezierPoint *start_pt;
  int grab_pointer;
  int op, replace;
  int x, y;
  int halfwidth, dummy;

  gdisp = (GDisplay *) gdisp_ptr;
  bezier_sel = tool->private;
  grab_pointer = 0;

  if (bezier_options->extend)
    {
      tool->gdisp_ptr = gdisp_ptr;
    }
  else
    {
      /*  If the tool was being used in another image...reset it  */
      if (tool->state == ACTIVE && gdisp_ptr != tool->gdisp_ptr) {
        draw_core_stop(bezier_sel->core, tool);
        bezier_select_reset (bezier_sel);
      }
    }

  gdisplay_untransform_coords (gdisp, bevent->x, bevent->y, &x, &y, TRUE, 0);

  /* get halfwidth in image coord */
  gdisplay_untransform_coords (gdisp, bevent->x + BEZIER_HALFWIDTH, 0, &halfwidth, &dummy, TRUE, 0);
  halfwidth -= x;

  curTool = active_tool;
  curSel = curTool->private;
  curGdisp = (GDisplay *) gdisp_ptr;
  active_tool->gdisp_ptr = gdisp_ptr;
  curCore = bezier_sel->core;

  switch (bezier_sel->state)
    {
    case BEZIER_START:
      grab_pointer = 1;
      tool->state = ACTIVE;
      tool->gdisp_ptr = gdisp_ptr;

      if (bevent->state & GDK_MOD1_MASK)
	{
	  init_edit_selection (tool, gdisp_ptr, bevent, MaskTranslate);
	  break;
	}
      else if (!(bevent->state & GDK_SHIFT_MASK) && !(bevent->state & GDK_CONTROL_MASK))
	if (! (layer_is_floating_sel (gimage_get_active_layer (gdisp->gimage))) &&
	    gdisplay_mask_value (gdisp, bevent->x, bevent->y) > HALF_WAY)
	  {
	    init_edit_selection (tool, gdisp_ptr, bevent, MaskToLayerTranslate);
	    break;
	  }

      bezier_sel->state = BEZIER_ADD;
      bezier_sel->draw = BEZIER_DRAW_CURRENT | BEZIER_DRAW_HANDLES;

      bezier_add_point (bezier_sel, BEZIER_ANCHOR, x, y);
      bezier_add_point (bezier_sel, BEZIER_CONTROL, x, y);

      draw_core_start (bezier_sel->core, gdisp->canvas->window, tool);
      break;
    case BEZIER_ADD:

      grab_pointer = 1;

      if(ModeEdit == EXTEND_EDIT)
	{ 
	  /* erase the handles */
	  bezier_sel->draw = BEZIER_DRAW_HANDLES;
	  draw_core_pause (bezier_sel->core, tool);
	  /* unset the current anchor and control */
	  bezier_sel->cur_anchor = NULL;
	  bezier_sel->cur_control = NULL;

	  grab_pointer = bezier_edit_point_on_curve(x,y,halfwidth,gdisp,bezier_sel,tool);

	  bezier_sel->draw = BEZIER_DRAW_HANDLES;
	  draw_core_resume (bezier_sel->core, tool);

	  if (grab_pointer)
	    gdk_pointer_grab (gdisp->canvas->window, FALSE,
			      GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON1_MOTION_MASK | GDK_BUTTON_RELEASE_MASK,
			      NULL, NULL, bevent->time);
	  return;
	}

      if(ModeEdit == EXTEND_REMOVE)
	{ 
	  if(bezier_sel->num_points < 6)
	    return;

	  /* erase the handles */
	  bezier_sel->draw = BEZIER_DRAW_HANDLES;
	  draw_core_pause (bezier_sel->core, tool);
	  /* unset the current anchor and control */
	  bezier_sel->cur_anchor = NULL;
	  bezier_sel->cur_control = NULL;

	  bezier_edit_point_on_curve(x,y,halfwidth,gdisp,bezier_sel,tool);

	  bezier_sel->draw = BEZIER_DRAW_HANDLES;
	  draw_core_resume (bezier_sel->core, tool);
	  return;
	}

      if(ModeEdit == EXTEND_ADD)
	{
	  if(bezier_sel->num_points < 5)
	    return;
	  bezier_sel->draw = BEZIER_DRAW_ALL; 
	  draw_core_pause (bezier_sel->core, tool); 

	  grab_pointer = bezier_add_point_on_segment(x,y,halfwidth,gdisp,bezier_sel,tool);

	  bezier_sel->draw = BEZIER_DRAW_ALL;
	  draw_core_resume (bezier_sel->core, tool);
	  break;
	}

      if(bezier_sel->cur_anchor)
	{
	  if (bezier_check_point (bezier_sel->cur_anchor, x, y, halfwidth))
	    {
	      break;
	    }
	  
	  if (bezier_sel->cur_anchor->next &&
	      bezier_check_point (bezier_sel->cur_anchor->next, x, y, halfwidth))
	    {
	      bezier_sel->cur_control = bezier_sel->cur_anchor->next;
	      break;
	    }

	  if (bezier_sel->cur_anchor->prev &&
	      bezier_check_point (bezier_sel->cur_anchor->prev, x, y, halfwidth))
	    {
	      bezier_sel->cur_control = bezier_sel->cur_anchor->prev;
	      break;
	    }
	}

      if (bezier_check_point (bezier_sel->points, x, y, halfwidth))
	{
	  bezier_sel->draw = BEZIER_DRAW_ALL;
	  draw_core_pause (bezier_sel->core, tool);

	  bezier_add_point (bezier_sel, BEZIER_CONTROL, x, y);
	  bezier_sel->last_point->next = bezier_sel->points;
	  bezier_sel->points->prev = bezier_sel->last_point;
	  bezier_sel->cur_anchor = bezier_sel->points;
	  bezier_sel->cur_control = bezier_sel->points->next;

	  bezier_sel->closed = 1;
	  bezier_sel->state = BEZIER_EDIT;
	  bezier_sel->draw = BEZIER_DRAW_ALL;

	  draw_core_resume (bezier_sel->core, tool);
	}
      else
	{
	  bezier_sel->draw = BEZIER_DRAW_HANDLES;
	  draw_core_pause (bezier_sel->core, tool);

	  bezier_add_point (bezier_sel, BEZIER_CONTROL, x, y);
	  bezier_add_point (bezier_sel, BEZIER_ANCHOR, x, y);
	  bezier_add_point (bezier_sel, BEZIER_CONTROL, x, y);

	  bezier_sel->draw = BEZIER_DRAW_CURRENT | BEZIER_DRAW_HANDLES;

	  draw_core_resume (bezier_sel->core, tool);
	}
      break;
    case BEZIER_EDIT:
      if (!bezier_sel->closed)
	fatal_error (_("tried to edit on open bezier curve in edit selection"));

      /* erase the handles */
      bezier_sel->draw = BEZIER_DRAW_HANDLES;
      draw_core_pause (bezier_sel->core, tool);

      /* unset the current anchor and control */
      bezier_sel->cur_anchor = NULL;
      bezier_sel->cur_control = NULL;

      points = bezier_sel->points;
      start_pt = bezier_sel->points;

      if (ModeEdit == EXTEND_ADD)
	{
	  if (bezier_sel->closed)
	    {
	      grab_pointer = bezier_add_point_on_segment(x,y,halfwidth,gdisp,bezier_sel,tool);
	    }
	}
      else
	{
	  grab_pointer = bezier_edit_point_on_curve(x,y,halfwidth,gdisp,bezier_sel,tool);
	}

      if (!grab_pointer && channel_value (bezier_sel->mask, x, y))
	{
	  replace = 0;
	  if ((bevent->state & GDK_SHIFT_MASK) && !(bevent->state & GDK_CONTROL_MASK))
	    op = ADD;
	  else if ((bevent->state & GDK_CONTROL_MASK) && !(bevent->state & GDK_SHIFT_MASK))
	    op = SUB;
	  else if ((bevent->state & GDK_CONTROL_MASK) && (bevent->state & GDK_SHIFT_MASK))
	    op = INTERSECT;
	  else
	    {
	      op = ADD;
	      replace = 1;
	    }
	  bezier_to_sel_internal(bezier_sel,tool,gdisp,op,replace);
	}
      else
	{
	  /* draw the handles */
	  bezier_sel->draw = BEZIER_DRAW_HANDLES;
	  draw_core_resume (bezier_sel->core, tool);
	}
      break;
    }

  if (grab_pointer)
    gdk_pointer_grab (gdisp->canvas->window, FALSE,
		      GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON1_MOTION_MASK | GDK_BUTTON_RELEASE_MASK,
		      NULL, NULL, bevent->time);

  /* Don't bother doing this if we don't have any points */
  if(bezier_sel->num_points > 0)
    paths_first_button_press(bezier_sel,gdisp);
}

static void
bezier_select_button_release (Tool           *tool,
			      GdkEventButton *bevent,
			      gpointer        gdisp_ptr)
{
  GDisplay * gdisp;
  BezierSelect *bezier_sel;

  gdisp = tool->gdisp_ptr;
  bezier_sel = tool->private;
  bezier_sel->state &= ~(BEZIER_DRAG);

  gdk_pointer_ungrab (bevent->time);
  gdk_flush ();

  if (bezier_sel->closed)
    bezier_convert (bezier_sel, tool->gdisp_ptr, SUBDIVIDE, NO);

  /* Here ?*/
  paths_newpoint_current(bezier_sel,gdisp);
}

static void
bezier_select_motion (Tool           *tool,
		      GdkEventMotion *mevent,
		      gpointer        gdisp_ptr)
{
  static int lastx, lasty;

  GDisplay * gdisp;
  BezierSelect * bezier_sel;
  BezierPoint * anchor;
  BezierPoint * opposite_control;
  int offsetx;
  int offsety;
  int x, y;

  if (tool->state != ACTIVE)
    return;

  gdisp = gdisp_ptr;
  bezier_sel = tool->private;

  if (!bezier_sel->cur_anchor || !bezier_sel->cur_control)
    return;

  if (mevent->state & GDK_MOD1_MASK)
    {
      bezier_sel->draw = BEZIER_DRAW_ALL;
    }
  else
    {
      bezier_sel->draw = BEZIER_DRAW_CURRENT | BEZIER_DRAW_HANDLES;
    }

  draw_core_pause (bezier_sel->core, tool);

  gdisplay_untransform_coords (gdisp, mevent->x, mevent->y, &x, &y, TRUE, 0);

  /* If this is the first point then change the state and "remember" the point.
   */
  if (!(bezier_sel->state & BEZIER_DRAG))
    {
      bezier_sel->state |= BEZIER_DRAG;
      lastx = x;
      lasty = y;
    }

  /* The Alt key is down... Move all the points of the bezier curve */

  if (mevent->state & GDK_MOD1_MASK)
    {
      int i;
      BezierPoint *tmp = bezier_sel->points;

      offsetx = x - lastx;
      offsety = y - lasty;

      for (i=0; i< bezier_sel->num_points; i++)
       {
         bezier_offset_point (tmp, offsetx, offsety);
         tmp = tmp->next;
       }
    }

  if (mevent->state & GDK_CONTROL_MASK)
    {
      /* the control key is down ... move the current anchor point */
      /* we must also move the neighboring control points appropriately */

      offsetx = x - lastx;
      offsety = y - lasty;

      bezier_offset_point (bezier_sel->cur_anchor, offsetx, offsety);
      bezier_offset_point (bezier_sel->cur_anchor->next, offsetx, offsety);
      bezier_offset_point (bezier_sel->cur_anchor->prev, offsetx, offsety);
    }
  else
    {
      /* the control key is not down ... we move the current control point */

      offsetx = x - bezier_sel->cur_control->x;
      offsety = y - bezier_sel->cur_control->y;

      bezier_offset_point (bezier_sel->cur_control, offsetx, offsety);

      /* if the shift key is not down then we align the opposite control */
      /* point...ie the opposite control point acts like a mirror of the */
      /* current control point */

      if (!(mevent->state & GDK_SHIFT_MASK))
	{
	  anchor = NULL;
	  opposite_control = NULL;

	  if (bezier_sel->cur_control->next)
	    {
	      if (bezier_sel->cur_control->next->type == BEZIER_ANCHOR)
		{
		  anchor = bezier_sel->cur_control->next;
		  opposite_control = anchor->next;
		}
	    }
	  if (bezier_sel->cur_control->prev)
	    {
	      if (bezier_sel->cur_control->prev->type == BEZIER_ANCHOR)
		{
		  anchor = bezier_sel->cur_control->prev;
		  opposite_control = anchor->prev;
		}
	    }

	  if (!anchor)
	    fatal_error (_("Encountered orphaned bezier control point"));

	  if (opposite_control)
	    {
	      offsetx = bezier_sel->cur_control->x - anchor->x;
	      offsety = bezier_sel->cur_control->y - anchor->y;

	      opposite_control->x = anchor->x - offsetx;
	      opposite_control->y = anchor->y - offsety;
	    }
	}
    }

  /* As we're moving all the control points of the curve,
     we have to redraw all !!!
     */

  if ( mevent->state & GDK_MOD1_MASK)
    bezier_sel->draw = BEZIER_DRAW_ALL;
  else
    bezier_sel->draw = BEZIER_DRAW_CURRENT | BEZIER_DRAW_HANDLES;

  draw_core_resume (bezier_sel->core, tool);

  lastx = x;
  lasty = y;
}

static void
bezier_select_control (Tool     *tool,
		       int       action,
		       gpointer  gdisp_ptr)
{
  BezierSelect * bezier_sel;

  bezier_sel = tool->private;



  switch (action)
    {
    case PAUSE :
      draw_core_pause (bezier_sel->core, tool);
      break;
    case RESUME :
      draw_core_resume (bezier_sel->core, tool);
      break;
    case HALT :
      draw_core_stop (bezier_sel->core, tool);
      bezier_select_reset (bezier_sel);
      break;
    default:
      break;
    }
}

static void
bezier_select_draw (Tool *tool)
{
  GDisplay * gdisp;
  BezierSelect * bezier_sel;
  BezierPoint * points;
  int num_points;
  int draw_curve;
  int draw_handles;
  int draw_current;

  gdisp = tool->gdisp_ptr;
  bezier_sel = tool->private;

  if (!bezier_sel->draw)
    return;

  draw_curve = bezier_sel->draw & BEZIER_DRAW_CURVE;
  draw_current = bezier_sel->draw & BEZIER_DRAW_CURRENT;
  draw_handles = bezier_sel->draw & BEZIER_DRAW_HANDLES;

  /* reset to the default drawing state of drawing the curve and handles */
  bezier_sel->draw = BEZIER_DRAW_ALL;

  /* transform the points from image space to screen space */
  points = bezier_sel->points;
  num_points = bezier_sel->num_points;

  while (points && num_points)
   {
      gdisplay_transform_coords (gdisp, points->x, points->y,
				 &points->sx, &points->sy, 0);
      points = points->next;
      num_points--;
    }

  if (draw_curve)
    bezier_draw_curve (bezier_sel,bezier_draw_segment_points,SCREEN_COORDS,NULL);
  if (draw_handles)
    bezier_draw_handles (bezier_sel);
  if (draw_current)
    bezier_draw_current (bezier_sel);

}

void
bezier_add_point (BezierSelect *bezier_sel,
		  int           type,
		  int           x,
		  int           y)
{
  BezierPoint *newpt;

  newpt = g_malloc (sizeof (BezierPoint));

  newpt->type = type;
  newpt->x = x;
  newpt->y = y;
  newpt->next = NULL;
  newpt->prev = NULL;

  if (bezier_sel->last_point)
    {
      bezier_sel->last_point->next = newpt;
      newpt->prev = bezier_sel->last_point;
      bezier_sel->last_point = newpt;
    }
  else
    {
      bezier_sel->points = newpt;
      bezier_sel->last_point = newpt;
    }

  switch (type)
    {
    case BEZIER_ANCHOR:
      bezier_sel->cur_anchor = newpt;
      break;
    case BEZIER_CONTROL:
      bezier_sel->cur_control = newpt;
      break;
    }

  bezier_sel->num_points += 1;
}

static void
bezier_offset_point (BezierPoint *pt,
		     int          x,
		     int          y)
{
  if (pt)
    {
      pt->x += x;
      pt->y += y;
    }
}

static int
bezier_check_point (BezierPoint *pt,
		    int          x,
		    int          y,
		    int		 halfwidth)
{
  int l, r, t, b;

  if (pt)
    {
      l = pt->x - halfwidth;
      r = pt->x + halfwidth;
      t = pt->y - halfwidth;
      b = pt->y + halfwidth;

      return ((x >= l) && (x <= r) && (y >= t) && (y <= b));
    }

  return 0;
}


static void
bezier_draw_handles (BezierSelect *bezier_sel)
{
  BezierPoint * points;
  int num_points;

  points = bezier_sel->points;
  num_points = bezier_sel->num_points;
  if (num_points <= 0)
    return;

  do {
    if (points == bezier_sel->cur_anchor)
      {
	bezier_draw_point (bezier_sel, points, 0);
	bezier_draw_point (bezier_sel, points->next, 0);
	bezier_draw_point (bezier_sel, points->prev, 0);
	bezier_draw_line (bezier_sel, points, points->next);
	bezier_draw_line (bezier_sel, points, points->prev);
      }
    else
      {
	bezier_draw_point (bezier_sel, points, 1);
      }

    if (points) points = points->next;
    if (points) points = points->next;
    if (points) points = points->next;
    num_points -= 3;
  } while (num_points > 0);
}

static void
bezier_draw_current (BezierSelect *bezier_sel)
{
  BezierPoint * points;

  points = bezier_sel->cur_anchor;

  if (points) points = points->prev;
  if (points) points = points->prev;
  if (points) points = points->prev;

  if (points)
    bezier_draw_segment (bezier_sel, points,
			 SUBDIVIDE, SCREEN_COORDS,
			 bezier_draw_segment_points,
			 NULL);

  if (points != bezier_sel->cur_anchor)
    {
      points = bezier_sel->cur_anchor;

      if (points) points = points->next;
      if (points) points = points->next;
      if (points) points = points->next;

      if (points)
	bezier_draw_segment (bezier_sel, bezier_sel->cur_anchor,
			     SUBDIVIDE, SCREEN_COORDS,
			     bezier_draw_segment_points,
			     NULL);
    }
}

static void
bezier_draw_point (BezierSelect *bezier_sel,
		   BezierPoint  *pt,
		   int           fill)
{
  if (pt)
    {
      switch (pt->type)
	{
	case BEZIER_ANCHOR:
	  if (fill)
	    {
	      gdk_draw_arc (bezier_sel->core->win, bezier_sel->core->gc, 1,
			    pt->sx - BEZIER_HALFWIDTH, pt->sy - BEZIER_HALFWIDTH,
			    BEZIER_WIDTH, BEZIER_WIDTH, 0, 23040);
	    }
	  else
	    {
	      gdk_draw_arc (bezier_sel->core->win, bezier_sel->core->gc, 0,
			    pt->sx - BEZIER_HALFWIDTH, pt->sy - BEZIER_HALFWIDTH,
			    BEZIER_WIDTH, BEZIER_WIDTH, 0, 23040);
	    }
	  break;
	case BEZIER_CONTROL:
	  if (fill)
	    {
	      gdk_draw_rectangle (bezier_sel->core->win, bezier_sel->core->gc, 1,
				  pt->sx - BEZIER_HALFWIDTH, pt->sy - BEZIER_HALFWIDTH,
				  BEZIER_WIDTH, BEZIER_WIDTH);
	    }
	  else
	    {
	      gdk_draw_rectangle (bezier_sel->core->win, bezier_sel->core->gc, 0,
				  pt->sx - BEZIER_HALFWIDTH, pt->sy - BEZIER_HALFWIDTH,
				  BEZIER_WIDTH, BEZIER_WIDTH);
	    }
	  break;
	}
    }
}

static void
bezier_draw_line (BezierSelect *bezier_sel,
		  BezierPoint  *pt1,
		  BezierPoint  *pt2)
{
  if (pt1 && pt2)
    {
      gdk_draw_line (bezier_sel->core->win,
		     bezier_sel->core->gc,
		     pt1->sx, pt1->sy, pt2->sx, pt2->sy);
    }
}

static void
bezier_draw_segment (BezierSelect     *bezier_sel,
		     BezierPoint      *points,
		     int               subdivisions,
		     int               space,
		     BezierPointsFunc  points_func,
		     gpointer          udata)
{
#define ROUND(x)  ((int) ((x) + 0.5))

  static GdkPoint gdk_points[256];
  static int npoints = 256;

  BezierMatrix geometry;
  BezierMatrix tmp1, tmp2;
  BezierMatrix deltas;
  double x, dx, dx2, dx3;
  double y, dy, dy2, dy3;
  double d, d2, d3;
  int lastx, lasty;
  int newx, newy;
  int index;
  int i;

  /* construct the geometry matrix from the segment */
  /* assumes that a valid segment containing 4 points is passed in */

  for (i = 0; i < 4; i++)
    {
      if (!points)
	fatal_error (_("bad bezier segment"));

      switch (space)
	{
	case IMAGE_COORDS:
	  geometry[i][0] = points->x;
	  geometry[i][1] = points->y;
	  break;
	case AA_IMAGE_COORDS:
	  geometry[i][0] = points->x * SUPERSAMPLE;
	  geometry[i][1] = points->y * SUPERSAMPLE;
	  break;
	case SCREEN_COORDS:
	  geometry[i][0] = points->sx;
	  geometry[i][1] = points->sy;
	  break;
	default:
	  fatal_error (_("unknown coordinate space: %d"), space);
	  break;
	}

      geometry[i][2] = 0;
      geometry[i][3] = 0;

      points = points->next;
    }

  /* subdivide the curve n times */
  /* n can be adjusted to give a finer or coarser curve */

  d = 1.0 / subdivisions;
  d2 = d * d;
  d3 = d * d * d;

  /* construct a temporary matrix for determining the forward diffencing deltas */

  tmp2[0][0] = 0;     tmp2[0][1] = 0;     tmp2[0][2] = 0;    tmp2[0][3] = 1;
  tmp2[1][0] = d3;    tmp2[1][1] = d2;    tmp2[1][2] = d;    tmp2[1][3] = 0;
  tmp2[2][0] = 6*d3;  tmp2[2][1] = 2*d2;  tmp2[2][2] = 0;    tmp2[2][3] = 0;
  tmp2[3][0] = 6*d3;  tmp2[3][1] = 0;     tmp2[3][2] = 0;    tmp2[3][3] = 0;

  /* compose the basis and geometry matrices */
  bezier_compose (basis, geometry, tmp1);

  /* compose the above results to get the deltas matrix */
  bezier_compose (tmp2, tmp1, deltas);

  /* extract the x deltas */
  x = deltas[0][0];
  dx = deltas[1][0];
  dx2 = deltas[2][0];
  dx3 = deltas[3][0];

  /* extract the y deltas */
  y = deltas[0][1];
  dy = deltas[1][1];
  dy2 = deltas[2][1];
  dy3 = deltas[3][1];

  lastx = x;
  lasty = y;

  gdk_points[0].x = lastx;
  gdk_points[0].y = lasty;
  index = 1;

  /* loop over the curve */
  for (i = 0; i < subdivisions; i++)
    {
      /* increment the x values */
      x += dx;
      dx += dx2;
      dx2 += dx3;

      /* increment the y values */
      y += dy;
      dy += dy2;
      dy2 += dy3;

      newx = ROUND (x);
      newy = ROUND (y);

      /* if this point is different than the last one...then draw it */
      if ((lastx != newx) || (lasty != newy))
	{
	  /* add the point to the point buffer */
	  gdk_points[index].x = newx;
	  gdk_points[index].y = newy;
	  index++;

	  /* if the point buffer is full put it to the screen and zero it out */
	  if (index >= npoints)
	    {
	      (* points_func) (bezier_sel, gdk_points, index, udata);
	      index = 0;
	    }
	}

      lastx = newx;
      lasty = newy;
    }

  /* if there are points in the buffer, then put them on the screen */
  if (index)
    (* points_func) (bezier_sel, gdk_points, index, udata);
}

static void
bezier_draw_segment_points (BezierSelect *bezier_sel,
			    GdkPoint     *points,
			    int           npoints,
			    gpointer      udata)
{
  gdk_draw_points (bezier_sel->core->win,
		   bezier_sel->core->gc, points, npoints);
}

static void
bezier_compose (BezierMatrix a,
		BezierMatrix b,
		BezierMatrix ab)
{
  int i, j;

  for (i = 0; i < 4; i++)
    {
      for (j = 0; j < 4; j++)
        {
          ab[i][j] = (a[i][0] * b[0][j] +
                      a[i][1] * b[1][j] +
                      a[i][2] * b[2][j] +
                      a[i][3] * b[3][j]);
        }
    }
}

static int start_convert;
static int width, height;
static int lastx;
static int lasty;

static void
bezier_convert (BezierSelect *bezier_sel,
		GDisplay     *gdisp,
		int           subdivisions,
		int           antialias)
{
  PixelRegion maskPR;
  BezierPoint * points;
  BezierPoint * start_pt;
  GSList * list;
  unsigned char *buf, *b;
  int draw_type;
  int * vals, val;
  int start, end;
  int x, x2, w;
  int i, j;

  if (!bezier_sel->closed)
    fatal_error (_("tried to convert an open bezier curve"));

  /* destroy previous mask */
  if (bezier_sel->mask)
    {
      channel_delete (bezier_sel->mask);
      bezier_sel->mask = NULL;
    }

  /* get the new mask's maximum extents */
  if (antialias)
    {
      buf = (unsigned char *) g_malloc (width);
      width = gdisp->gimage->width * SUPERSAMPLE;
      height = gdisp->gimage->height * SUPERSAMPLE;
      draw_type = AA_IMAGE_COORDS;
      /* allocate value array  */
      vals = (int *) g_malloc (sizeof (int) * width);
    }
  else
    {
      buf = NULL;
      width = gdisp->gimage->width;
      height = gdisp->gimage->height;
      draw_type = IMAGE_COORDS;
      vals = NULL;
    }

  /* create a new mask */
  bezier_sel->mask = channel_ref (channel_new_mask (gdisp->gimage, 
						    gdisp->gimage->width,
						    gdisp->gimage->height));

  /* allocate room for the scanlines */
  bezier_sel->scanlines = g_malloc (sizeof (GSList *) * height);

  /* zero out the scanlines */
  for (i = 0; i < height; i++)
    bezier_sel->scanlines[i] = NULL;

  /* scan convert the curve */
  points = bezier_sel->points;
  start_pt = bezier_sel->points;
  start_convert = 1;

  do {
    bezier_draw_segment (bezier_sel, points,
			 subdivisions, draw_type,
			 bezier_convert_points,
			 NULL);

    /*  advance to the next segment  */
    points = points->next;
    points = points->next;
    points = points->next;
  } while (points != start_pt);

  if (antialias)
    bezier_convert_line (bezier_sel->scanlines, lastx, lasty,
			 bezier_sel->points->x * SUPERSAMPLE,
			 bezier_sel->points->y * SUPERSAMPLE);
  else
    bezier_convert_line (bezier_sel->scanlines, lastx, lasty,
			 bezier_sel->points->x, bezier_sel->points->y);

  pixel_region_init (&maskPR, drawable_data (GIMP_DRAWABLE(bezier_sel->mask)), 
		     0, 0,
		     drawable_width (GIMP_DRAWABLE(bezier_sel->mask)),
		     drawable_height (GIMP_DRAWABLE(bezier_sel->mask)), TRUE);
  for (i = 0; i < height; i++)
    {
      list = bezier_sel->scanlines[i];

      /*  zero the vals array  */
      if (antialias && !(i % SUPERSAMPLE))
	memset (vals, 0, width * sizeof (int));

      while (list)
        {
          x = (long) list->data;
          list = list->next;
/*
          if (!list)
	    g_message (_("cannot properly scanline convert bezier curve: %d"), i);
          else
*/
            {
	      /*  bounds checking  */
	      x = BOUNDS (x, 0, width);
	      x2 = BOUNDS ((long) list->data, 0, width);

	      w = x2 - x;

	      if (!antialias)
		channel_add_segment (bezier_sel->mask, x, i, w, 255);
	      else
		for (j = 0; j < w; j++)
		  vals[j + x] += 255;

              list = g_slist_next (list);
            }
        }

      if (antialias && !((i+1) % SUPERSAMPLE))
	{
	  b = buf;
	  start = 0;
	  end = width;
	  for (j = start; j < end; j += SUPERSAMPLE)
	    {
	      val = 0;
	      for (x = 0; x < SUPERSAMPLE; x++)
		val += vals[j + x];

	      *b++ = (unsigned char) (val / SUPERSAMPLE2);
	    }

	  pixel_region_set_row (&maskPR, 0, (i / SUPERSAMPLE), 
				drawable_width (GIMP_DRAWABLE(bezier_sel->mask)), buf);
	}

      g_slist_free (bezier_sel->scanlines[i]);
    }

  if (antialias)
    {
      g_free (vals);
      g_free (buf);
    }

  g_free (bezier_sel->scanlines);
  bezier_sel->scanlines = NULL;

  channel_invalidate_bounds (bezier_sel->mask);
}

static void
bezier_convert_points (BezierSelect *bezier_sel,
		       GdkPoint     *points,
		       int           npoints,
		       gpointer      udata)
{
  int i;

  if (start_convert)
    start_convert = 0;
  else
    bezier_convert_line (bezier_sel->scanlines, lastx, lasty, points[0].x, points[0].y);

  for (i = 0; i < (npoints - 1); i++)
    {
      bezier_convert_line (bezier_sel->scanlines,
			   points[i].x, points[i].y,
			   points[i+1].x, points[i+1].y);
    }

  lastx = points[npoints-1].x;
  lasty = points[npoints-1].y;
}

static void
bezier_convert_line (GSList ** scanlines,
		     int       x1,
		     int       y1,
		     int       x2,
		     int       y2)
{
  int dx, dy;
  int error, inc;
  int tmp;
  float slope;

  if (y1 == y2)
    return;

  if (y1 > y2)
    {
      tmp = y2; y2 = y1; y1 = tmp;
      tmp = x2; x2 = x1; x1 = tmp;
    }

  if (y1 < 0)
    {
      if (y2 < 0)
	return;

      if (x2 == x1)
	{
	  y1 = 0;
	}
      else
	{
	  slope = (float) (y2 - y1) / (float) (x2 - x1);
	  x1 = x2 + (0 - y2) / slope;
	  y1 = 0;
	}
    }

  if (y2 >= height)
    {
      if (y1 >= height)
	return;

      if (x2 == x1)
	{
	  y2 = height;
	}
      else
	{
	  slope = (float) (y2 - y1) / (float) (x2 - x1);
	  x2 = x1 + (height - y1) / slope;
	  y2 = height;
	}
    }

  if (y1 == y2)
    return;

  dx = x2 - x1;
  dy = y2 - y1;

  scanlines = &scanlines[y1];

  if (((dx < 0) ? -dx : dx) > ((dy < 0) ? -dy : dy))
    {
      if (dx < 0)
        {
          inc = -1;
          dx = -dx;
        }
      else
        {
          inc = 1;
        }

      error = -dx /2;
      while (x1 != x2)
        {
          error += dy;
          if (error > 0)
            {
              error -= dx;
	      *scanlines = bezier_insert_in_list (*scanlines, x1);
	      scanlines++;
            }

          x1 += inc;
        }
    }
  else
    {
      error = -dy /2;
      if (dx < 0)
        {
          dx = -dx;
          inc = -1;
        }
      else
        {
          inc = 1;
        }

      while (y1++ < y2)
        {
	  *scanlines = bezier_insert_in_list (*scanlines, x1);
	  scanlines++;

          error += dx;
          if (error > 0)
            {
              error -= dy;
              x1 += inc;
            }
        }
    }
}

static GSList *
bezier_insert_in_list (GSList * list,
		       int      x)
{
  GSList * orig = list;
  GSList * rest;

  if (!list)
    return g_slist_prepend (list, (void *) ((long) x));

  while (list)
    {
      rest = g_slist_next (list);
      if (x < (long) list->data)
        {
          rest = g_slist_prepend (rest, list->data);
          list->next = rest;
          list->data = (void *) ((long) x);
          return orig;
        }
      else if (!rest)
        {
          g_slist_append (list, (void *) ((long) x));
          return orig;
        }
      list = g_slist_next (list);
    }

  return orig;
}

void
bezier_paste_bezierselect_to_current(GDisplay *gdisp,BezierSelect *bsel)
{
  BezierPoint *pts;
  gint i;
  Tool * tool;

  /*  If the tool was being used before clear it */
  if (active_tool_type == BEZIER_SELECT &&
      active_tool->state == ACTIVE)
    {
      BezierSelect *bezier_sel = (BezierSelect*)active_tool->private;
      if(bezier_sel)
	{
	  draw_core_stop ( curSel->core, active_tool );
	  bezier_select_reset (bezier_sel);
	}
    }

  gtk_widget_activate (tool_info[BEZIER_SELECT].tool_widget);
  tools_select(BEZIER_SELECT);
  active_tool->paused_count = 0;
  active_tool->gdisp_ptr = gdisp;;
  active_tool->drawable = gimage_active_drawable (gdisp->gimage);  

  tool = active_tool;

  bezier_select_reset( curSel );

  draw_core_start (curSel->core, gdisp->canvas->window, tool);

  tool->state = ACTIVE;

  pts = (BezierPoint *) bsel->points;

  for (i=0; i< bsel->num_points; i++)
    {
      bezier_add_point( curSel, pts->type, pts->x, pts->y);
      pts = pts->next;
    }
      
  if ( bsel->closed )
    {
      curSel->last_point->next = curSel->points;
      curSel->points->prev = curSel->last_point;
      curSel->cur_anchor = curSel->points;
      curSel->cur_control = curSel-> points->next;
      curSel->closed = 1;
      if (curTool->gdisp_ptr)
	bezier_convert(curSel, curTool->gdisp_ptr, SUBDIVIDE, NO);
    }

  if(bsel->num_points == 0)
    {
      curSel->state = BEZIER_START;
      curSel->draw = 0;
      draw_core_stop( curSel->core, curTool);
    }
  else
    {
      curSel->state = bsel->state;
      curSel->draw = BEZIER_DRAW_ALL;
      draw_core_resume( curSel->core, curTool);
    }
}

static void
bezier_to_sel_internal(BezierSelect  *bezier_sel,
		       Tool          *tool,
		       GDisplay      *gdisp,
		       gint           op, 
		       gint           replace)
{
  /*  If we're antialiased, then recompute the
   *  mask...
   */
  if (bezier_options->antialias)
    bezier_convert (bezier_sel, tool->gdisp_ptr, SUBDIVIDE, YES);
  
  if (!bezier_options->extend)
    {
      tool->state = INACTIVE;
      bezier_sel->draw = BEZIER_DRAW_CURVE;
      draw_core_resume (bezier_sel->core, tool);
      
      bezier_sel->draw = 0;
      draw_core_stop (bezier_sel->core, tool);
    }

   if (replace)
    gimage_mask_clear (gdisp->gimage);
  else
    gimage_mask_undo (gdisp->gimage);
  
  if (bezier_options->feather)
    channel_feather (bezier_sel->mask,
		     gimage_get_mask (gdisp->gimage),
		     bezier_options->feather_radius, op, 0, 0);
  else
    channel_combine_mask (gimage_get_mask (gdisp->gimage),
			  bezier_sel->mask, op, 0, 0);
  
  /*  show selection on all views  */
  bezier_sel->draw = BEZIER_DRAW_HANDLES;
  draw_core_resume (bezier_sel->core, tool); 

  gdisplays_flush ();
}

static int
test_add_point_on_segment (BezierSelect     *bezier_sel,
			    BezierPoint      *pt,
			    int               subdivisions,
			    int               space,
			    int xpos, 
			    int ypos, 
			    int halfwidth)

{
  BezierPoint *points;
  BezierMatrix geometry;
  BezierMatrix tmp1, tmp2;
  BezierMatrix deltas;
  double x, dx, dx2, dx3;
  double y, dy, dy2, dy3;
  double d, d2, d3;
  int lastx, lasty;
  int newx, newy;
  int i;
  double ratio;

  /* construct the geometry matrix from the segment */
  /* assumes that a valid segment containing 4 points is passed in */
  /* ALT ignore invalid segments since we might be working on an open curve */

  points = pt;

  ratio = -1.0;

  for (i = 0; i < 4; i++)
    {
      if (!points)
	return 0;

      switch (space)
	{
	case IMAGE_COORDS:
	  geometry[i][0] = points->x;
	  geometry[i][1] = points->y;
	  break;
	case AA_IMAGE_COORDS:
	  geometry[i][0] = points->x * SUPERSAMPLE;
	  geometry[i][1] = points->y * SUPERSAMPLE;
	  break;
	case SCREEN_COORDS:
	  geometry[i][0] = points->sx;
	  geometry[i][1] = points->sy;
	  break;
	default:
	  fatal_error (_("unknown coordinate space: %d"), space);
	  break;
	}

      geometry[i][2] = 0;
      geometry[i][3] = 0;

      points = points->next;
    }

  /* subdivide the curve n times */
  /* n can be adjusted to give a finer or coarser curve */

  d = 1.0 / subdivisions;
  d2 = d * d;
  d3 = d * d * d;

  /* construct a temporary matrix for determining the forward diffencing deltas */

  tmp2[0][0] = 0;     tmp2[0][1] = 0;     tmp2[0][2] = 0;    tmp2[0][3] = 1;
  tmp2[1][0] = d3;    tmp2[1][1] = d2;    tmp2[1][2] = d;    tmp2[1][3] = 0;
  tmp2[2][0] = 6*d3;  tmp2[2][1] = 2*d2;  tmp2[2][2] = 0;    tmp2[2][3] = 0;
  tmp2[3][0] = 6*d3;  tmp2[3][1] = 0;     tmp2[3][2] = 0;    tmp2[3][3] = 0;

  /* compose the basis and geometry matrices */
  bezier_compose (basis, geometry, tmp1);

  /* compose the above results to get the deltas matrix */
  bezier_compose (tmp2, tmp1, deltas);

  /* extract the x deltas */
  x = deltas[0][0];
  dx = deltas[1][0];
  dx2 = deltas[2][0];
  dx3 = deltas[3][0];

  /* extract the y deltas */
  y = deltas[0][1];
  dy = deltas[1][1];
  dy2 = deltas[2][1];
  dy3 = deltas[3][1];

  lastx = x;
  lasty = y;

  /* loop over the curve */
  for (i = 0; i < subdivisions; i++)
    {
      /* increment the x values */
      x += dx;
      dx += dx2;
      dx2 += dx3;

      /* increment the y values */
      y += dy;
      dy += dy2;
      dy2 += dy3;

      newx = ROUND (x);
      newy = ROUND (y);

      /* if this point is different than the last one...then test it */
      if ((lastx != newx) || (lasty != newy))
	{
	  int l, r, b, t;
	  
	  l = newx - halfwidth;
	  r = newx + halfwidth;
	  t = newy - halfwidth;
	  b = newy + halfwidth;
	  
	  if  ((xpos >= l) && (xpos <= r) && (ypos >= t) && (ypos <= b))
	    {
	      /* so we found one point in the square hit */
	      
	      ratio = (double)i/(double)subdivisions;

	      /* We found the exact point on the curve, so take it ...*/

	      if ((xpos==newx) && (ypos==newy)) break;

	      /* to Implement :

		 keep each time the nearest point of the curve from where we've clicked
		 in the case where we haven't click exactely on the curve.
	      */

	    }
	}
      lastx = newx;
      lasty = newy;
    }

  /* we found a point on the curve */

  if (ratio >= 0.0)
    {
      BezierPoint *pts, *pt1, *pt2, *pt3;
      BezierPoint *P00, *P01, *P02, *P03;
      BezierPoint P10, P11, P12;
      BezierPoint P20, P21;
      BezierPoint P30;

      pts = pt;

      P00 = pts;
      pts = pts->next;
      P01 = pts;
      pts = pts->next;
      P02 = pts;
      pts = pts->next;
      P03 = pts;

      /* De Casteljau algorithme 
	 [Advanced Animation & Randering Technics / Alan & Mark WATT]
	 [ADDISON WESLEY ref 54412]
	 Iteratif way of drawing a Bezier curve by geometrical approch 
	 
	 P0x represent the four controls points ( anchor / control /control /anchor ) 
	 P30 represent the new anchor point to add on the curve 
	 P2x represent the new control points of P30
	 P1x represent the new values of the control points P01 and P02

	 so if we moves ratio from 0 to 1 we draw the all curve between P00 and P03
      */
	 
      P10.x = (int)((1-ratio)*P00->x + ratio * P01->x);
      P10.y = (int)((1-ratio)*P00->y + ratio * P01->y);

      P11.x = (1-ratio)*P01->x + ratio * P02->x;
      P11.y = (1-ratio)*P01->y + ratio * P02->y;

      P12.x = (1-ratio)*P02->x + ratio * P03->x;
      P12.y = (1-ratio)*P02->y + ratio * P03->y;

      P20.x = (1-ratio)*P10.x + ratio * P11.x;
      P20.y = (1-ratio)*P10.y + ratio * P11.y;

      P21.x = (1-ratio)*P11.x + ratio * P12.x;
      P21.y = (1-ratio)*P11.y + ratio * P12.y;

      P30.x = (1-ratio)*P20.x + ratio * P21.x;
      P30.y = (1-ratio)*P20.y + ratio * P21.y;
      
      P01->x = P10.x;
      P01->y = P10.y;

      P02->x = P12.x;
      P02->y = P12.y;

      /* All the computes are done, let's insert the new point on the curve */

      pt1 = g_malloc (sizeof (BezierPoint));
      pt2 = g_malloc (sizeof (BezierPoint));
      pt3 = g_malloc (sizeof (BezierPoint));
      
      pt1->type = BEZIER_CONTROL;
      pt2->type = BEZIER_ANCHOR;
      pt3->type = BEZIER_CONTROL;
      
      pt1->x = P20.x; pt1->y = P20.y;    
      pt2->x = P30.x; pt2->y = P30.y;
      pt3->x = P21.x; pt3->y = P21.y;
      
      
      P01->next  = pt1;
      
      pt1->prev = P01;
      pt1->next = pt2;
      
      pt2->prev = pt1;
      pt2->next = pt3;
      
      pt3->prev = pt2; 
      pt3->next = P02;
      
      P02->prev = pt3;
      
      bezier_sel->num_points += 3;

      bezier_sel->cur_anchor = pt2;
      bezier_sel->cur_control = pt1;

      return 1;
    }

  return 0;
  
}

void bezier_select_mode(gint mode)
{
  ModeEdit = mode;
}

/* The curve has to be closed to do a selection. */

void
bezier_to_selection(BezierSelect *bezier_sel,
		    GDisplay     *gdisp)
{
  /* Call the internal function */
  if(!bezier_sel->closed)
    {
      g_warning("Curve not closed");
      return;
    }

  /* force the passed selection to be the current selection..*/
  /* This loads it into curSel for this image */
  bezier_paste_bezierselect_to_current(gdisp,bezier_sel);
  bezier_to_sel_internal(curSel,curTool,gdisp,ADD,1);
}

void printSel( BezierSelect *sel)
{
  BezierPoint *pt;
  int i;

  pt = sel->points;

  printf("\n");

  for(i=0; i<sel->num_points; i++)
    {
      printf("%d %d %d\n", i, pt->x, pt->y);
      pt = pt->next;
    }

  printf("core : %p\n", sel->core);
  printf("closed : %d\n", sel->closed);
  printf("draw : %d\n", sel->draw);
  printf("state: %d\n", sel->state);
}

/* check whether vectors (offx, offy), (l_offx, l_offy) have the same angle. */
static gboolean
stroke_interpolatable (int offx, int offy, int l_offx, int l_offy, gdouble error)
{
  if      ((offx == l_offx) & (offy == l_offy))
    return TRUE;
  else if ((offx == 0) | (l_offx == 0))
    if (offx == l_offx)
      return ((0 <= offy) & (0 <= offy)) | ((offy < 0) & (l_offy < 0));
    else
      return FALSE;
  else if ((offy == 0) | (l_offy == 0))
    if (offy == l_offy)
      return ((0 < offx) & (0 < l_offx)) | ((offx < 0) & (l_offx < 0));
    else
      return FALSE;
  /* At this point, we can assert: offx, offy, l_offx, l_offy != 0 */
  else if (((0 < offx) & (0 < l_offx)) | ((offx < 0) & (l_offx < 0)))
    {
      gdouble	grad1, grad2;

      if (ABS (offy) < ABS (offx))
	{
	  grad1 = (gdouble) offy / (gdouble) offx;
	  grad2 = (gdouble) l_offy / (gdouble) l_offx;
	}
      else
	{
	  grad1 = (gdouble) offx / (gdouble) offy;
	  grad2 = (gdouble) l_offx / (gdouble) l_offy;
	}
      /* printf ("error: %f / %f\n", ABS (grad1 - grad2), error); */
      return (ABS (grad1 - grad2) <= error);
    }
  else
    return FALSE;
}

static void
bezier_stack_points_aux (GdkPoint *points,
			 int      start,
			 int	  end,
			 gdouble  error,
			 BezierRenderPnts *rpnts)
{
  const gint	expand_size = 32;
  gint		med;
  gint		offx, offy, l_offx, l_offy;

  if (rpnts->stroke_points == NULL)
    return;

  /* BASE CASE: stack the end point */
  if (end - start <= 1)
    {
      if ((rpnts->stroke_points[rpnts->num_stroke_points * 2 - 2] == points[end].x)
	  && (rpnts->stroke_points[rpnts->num_stroke_points * 2 - 1] == points[end].y))
	return;

      rpnts->num_stroke_points++;
      if (rpnts->len_stroke_points <= rpnts->num_stroke_points)
	{
	  rpnts->len_stroke_points += expand_size;
	  rpnts->stroke_points = g_renew (double, rpnts->stroke_points, 2 * rpnts->len_stroke_points);
	  if (rpnts->stroke_points == NULL)
	    {
	      rpnts->len_stroke_points = rpnts->num_stroke_points = 0;
	      return;
	    }
	}
      rpnts->stroke_points[rpnts->num_stroke_points * 2 - 2] = points[end].x;
      rpnts->stroke_points[rpnts->num_stroke_points * 2 - 1] = points[end].y;
      return;
    }

  if (end - start <= 32)
    {
      gint i;

      for (i = start+ 1; i <= end; i++)
	bezier_stack_points_aux (points, i, i, 0,rpnts);
      return;
    }
  /* Otherwise, check whether to divide the segment recursively */
  offx = points[end].x - points[start].x;
  offy = points[end].y - points[start].y;
  med = (end + start) / 2;

  l_offx = points[med].x - points[start].x;
  l_offy = points[med].y - points[start].y;

  if (! stroke_interpolatable (offx, offy, l_offx, l_offy, error))
    {
      bezier_stack_points_aux (points, start, med, error, rpnts);
      bezier_stack_points_aux (points, med, end, error, rpnts);
      return;
    }

  l_offx = points[end].x - points[med].x;
  l_offy = points[end].y - points[med].y;

  if (! stroke_interpolatable (offx, offy, l_offx, l_offy, error))
    {
      bezier_stack_points_aux (points, start, med, error, rpnts);
      bezier_stack_points_aux (points, med, end, error, rpnts);
      return;
    }
  /* Now, the curve can be represented by a points pair: (start, end).
     So, add the last point to stroke_points. */
  bezier_stack_points_aux (points, end, end, 0, rpnts);
}

static void
bezier_stack_points (BezierSelect *bezier_sel,
		     GdkPoint     *points,
		     int           npoints,
		     gpointer      udata)
{
  gint	i;
  gint	expand_size = 32;
  gint	minx, maxx, miny, maxy;
  gdouble error;
  BezierRenderPnts *rpnts = udata;

  if (npoints < 2)		/* Does this happen? */
    return;

  if (rpnts->stroke_points == NULL)	/*  initialize it here */
    {
      rpnts->num_stroke_points = 0;
      rpnts->len_stroke_points = expand_size;
      rpnts->stroke_points = g_new (double, 2 * rpnts->len_stroke_points);
    }

  maxx = minx = points[0].x;
  maxy = miny = points[0].y;
  for (i = 1; i < npoints; i++)
    {
      if (points[i].x < minx)
	minx = points[i].x;
      else if (maxx < points[i].x)
	maxx = points[i].x;
      if (points[i].y < miny)
	miny = points[i].x;
      else if (maxy < points[i].y)
	maxy = points[i].y;
    }
  /* allow one pixel fluctuation */
  error = 2.0 / MAX(maxx - minx, maxy - miny);

  /* add the start point */
  bezier_stack_points_aux (points, 0, 0, 0, rpnts);

  /* divide segments recursively */
  bezier_stack_points_aux (points, 0, npoints - 1, error, rpnts);

  /* printf ("npoints: %d\n", npoints); */
}

static gint
bezier_gen_points(BezierSelect     *bezier_sel,
		  int	            open_path,
		  BezierRenderPnts *rpnts)
{
  BezierPoint * points;
  int num_points;
  int redraw = FALSE;

  /* stack points */
  points = bezier_sel->points;
  num_points = bezier_sel->num_points;
  
  if (bezier_sel->closed && (! open_path))
    {
      BezierPoint * start_pt;
      
      start_pt = bezier_sel->points;
      
      do {
	bezier_draw_segment (bezier_sel, points,
			     SUBDIVIDE, IMAGE_COORDS,
			     bezier_stack_points,
			     (gpointer)rpnts);
	
	points = points->next;
	points = points->next;
	points = points->next;
      } while (points != start_pt);
    }
  else
    {
      if (bezier_sel->closed)
	{
	  redraw = TRUE;
	  num_points--;
	}
      while (num_points >= 4)
	{
	  bezier_draw_segment (bezier_sel, points,
			       SUBDIVIDE, IMAGE_COORDS,
			       bezier_stack_points,
			       (gpointer)rpnts);

	  points = points->next;
	  points = points->next;
	  points = points->next;
	  num_points -= 3;
	}
    }

  return (redraw);
}

void
bezier_stroke (BezierSelect *bezier_sel,
	       GDisplay     *gdisp,
	       int          subdivisions,
	       int	    open_path)
{
  Argument *return_vals;
  int nreturn_vals;
  int redraw;
  BezierRenderPnts *rpnts = g_new0(BezierRenderPnts,1);

  redraw = bezier_gen_points(bezier_sel,open_path,rpnts);

  if (rpnts->stroke_points)
    {
      GimpDrawable *drawable;
      int offset_x, offset_y;
    
      drawable = gimage_active_drawable (gdisp->gimage);
      gimp_drawable_offsets (drawable, &offset_x, &offset_y);

      if ((offset_x != 0) || (offset_y != 0))
       {
         gdouble *ptr;

         ptr = rpnts->stroke_points;
         while (ptr < rpnts->stroke_points + (rpnts->num_stroke_points * 2))
           {
             *ptr++ -= offset_x;
             *ptr++ -= offset_y;
           }
       }

      return_vals = procedural_db_run_proc ("gimp_paintbrush",
					    &nreturn_vals,
					    PDB_DRAWABLE, drawable_ID (drawable),
					    PDB_FLOAT, (gdouble) 0,
					    PDB_INT32, (gint32) rpnts->num_stroke_points * 2,
					    PDB_FLOATARRAY, rpnts->stroke_points,
					    PDB_END);

      if (return_vals[0].value.pdb_int == PDB_SUCCESS)
	{
	  if (redraw)
	    {
	      /* FIXME: how to update the image? */
	    }
	  gdisplays_flush ();
	}
      else
	g_message (_("Paintbrush operation failed."));

      procedural_db_destroy_args (return_vals, nreturn_vals);

      g_free (rpnts->stroke_points);
    }
  /* printf ("num_stroke_points: %d\ndone.\n", num_stroke_points); */

  rpnts->stroke_points = NULL;
  rpnts->len_stroke_points = rpnts->num_stroke_points = 0;

  g_free(rpnts);
}

static void
bezier_draw_segment_for_distance (BezierSelect     *bezier_sel,
				  BezierPoint      *points,
				  int               subdivisions,
				  BezierDistance   *bdist)
{
  BezierMatrix geometry;
  BezierMatrix tmp1, tmp2;
  BezierMatrix deltas;
  double x, dx, dx2, dx3;
  double y, dy, dy2, dy3;
  double d, d2, d3;
  int index;
  int i;

  /* construct the geometry matrix from the segment */
  /* assumes that a valid segment containing 4 points is passed in */

  if(bdist->found)
    return;

  for (i = 0; i < 4; i++)
    {
      if (!points)
	fatal_error (_("bad bezier segment"));

      geometry[i][0] = points->x;
      geometry[i][1] = points->y;
      geometry[i][2] = 0;
      geometry[i][3] = 0;

      points = points->next;
    }

  /* subdivide the curve n times */
  /* n can be adjusted to give a finer or coarser curve */

  d = 1.0 / subdivisions;
  d2 = d * d;
  d3 = d * d * d;

  /* construct a temporary matrix for determining the forward diffencing deltas */

  tmp2[0][0] = 0;     tmp2[0][1] = 0;     tmp2[0][2] = 0;    tmp2[0][3] = 1;
  tmp2[1][0] = d3;    tmp2[1][1] = d2;    tmp2[1][2] = d;    tmp2[1][3] = 0;
  tmp2[2][0] = 6*d3;  tmp2[2][1] = 2*d2;  tmp2[2][2] = 0;    tmp2[2][3] = 0;
  tmp2[3][0] = 6*d3;  tmp2[3][1] = 0;     tmp2[3][2] = 0;    tmp2[3][3] = 0;

  /* compose the basis and geometry matrices */
  bezier_compose (basis, geometry, tmp1);

  /* compose the above results to get the deltas matrix */
  bezier_compose (tmp2, tmp1, deltas);

  /* extract the x deltas */
  x = deltas[0][0];
  dx = deltas[1][0];
  dx2 = deltas[2][0];
  dx3 = deltas[3][0];

  /* extract the y deltas */
  y = deltas[0][1];
  dy = deltas[1][1];
  dy2 = deltas[2][1];
  dy3 = deltas[3][1];

  index = 1;

  /* loop over the curve */
  for (i = 0; i < subdivisions; i++)
    {
      /* increment the x values */
      x += dx;
      dx += dx2;
      dx2 += dx3;

      /* increment the y values */
      y += dy;
      dy += dy2;
      dy2 += dy3;

/*       printf("x = %g, y = %g\n",x,y); */

      /* if this point is different than the last one...then draw it */
      /* Note :
       * It assumes the udata is the place we want the 
       * floating version of the coords to be stuffed.
       * These are needed when we calculate the gradient of the 
       * curve.
       */

      if(!bdist->firstpnt)
	{
	  gdouble rx = x;
	  gdouble ry = y;
 	  gdouble dx = bdist->lastx - rx; 
 	  gdouble dy = bdist->lasty - ry; 

 	  bdist->curdist += sqrt((dx*dx)+(dy*dy)); 
 	  if(bdist->curdist >= bdist->dist) 
 	    { 
 	      *(bdist->x) = (gint)ROUND((rx + dx/2)); 
 	      *(bdist->y) = (gint)ROUND((ry + dy/2)); 
 	      if(dx == 0.0) 
 		*(bdist->gradient) = G_MAXDOUBLE; 
 	      else 
 		*(bdist->gradient) = dy/dx; 

/* 	      printf("found x = %d, y = %d\n",*(bdist->x),*(bdist->y)); */
	      bdist->found = TRUE;
 	      break; 
 	    } 
 	  bdist->lastx = rx; 
 	  bdist->lasty = ry; 
	}
      else
	{
	  bdist->firstpnt = FALSE;
	  bdist->lastx = x;
	  bdist->lasty = y;
	}
    }
}

static void
bezier_draw_curve_for_distance (BezierSelect    *bezier_sel,
				BezierDistance  *udata)
{
  BezierPoint * points;
  BezierPoint * start_pt;
  int num_points;

  points = bezier_sel->points;

  if (bezier_sel->closed)
    {
      start_pt = bezier_sel->points;

      do {
	bezier_draw_segment_for_distance (bezier_sel, points,
					  SUBDIVIDE, 
					  udata);

	points = points->next;
	points = points->next;
	points = points->next;
      } while (points != start_pt);
    }
  else
    {
      num_points = bezier_sel->num_points;

      while (num_points >= 4)
	{
	  bezier_draw_segment_for_distance (bezier_sel, points,
					    SUBDIVIDE, 
					    udata);
	  points = points->next;
	  points = points->next;
	  points = points->next;
	  num_points -= 3;
	}
    }
}

gint
bezier_distance_along(BezierSelect *bezier_sel,
		      int	    open_path,
		      gdouble       dist,
		      gint         *x,
		      gint         *y,
		      gdouble      *gradient)
{
  /* Render the curve as points then walk along it... */
  BezierDistance *bdist = g_new0(BezierDistance,1);
  gint ret;

  bdist->firstpnt = TRUE;
  bdist->curdist = 0.0;
  bdist->lastx = 0.0;
  bdist->lasty = 0.0;
  bdist->dist = dist;
  bdist->x = x;
  bdist->y = y;
  bdist->gradient = gradient;
  bdist->found = FALSE;

  bezier_draw_curve_for_distance (bezier_sel,bdist);
  ret = bdist->found;

  g_free(bdist);
  return (ret);
}