gimp/app/paintbrush.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 <math.h>
#include "appenv.h"
#include "gimpbrushlist.h"
#include "drawable.h"
#include "errors.h"
#include "gdisplay.h"
#include "gradient.h"
#include "paint_funcs.h"
#include "paint_core.h"
#include "palette.h"
#include "paintbrush.h"
#include "selection.h"
#include "tool_options_ui.h"
#include "tools.h"

#include "libgimp/gimpintl.h"

/*  defines  */
#define  PAINT_LEFT_THRESHOLD  0.05

/*  the paintbrush structures  */

typedef struct _PaintOptions PaintOptions;
struct _PaintOptions
{
  ToolOptions  tool_options;

  double       fade_out;
  double       fade_out_d;
  GtkObject   *fade_out_w;

  int          use_gradient;
  int          use_gradient_d;
  GtkWidget   *use_gradient_w;

  double       gradient_length;
  double       gradient_length_d;
  GtkObject   *gradient_length_w;

  int          gradient_type;
  int          gradient_type_d;
  GtkWidget   *gradient_type_w;

  gboolean     incremental;
  gboolean     incremental_d;
  GtkWidget   *incremental_w;
};

/*  the paint brush tool options  */
static PaintOptions *paintbrush_options = NULL;

/*  local variables  */
static double        non_gui_fade_out;
static double        non_gui_gradient_length;
static int           non_gui_gradient_type;
static double        non_gui_incremental;


/*  forward function declarations  */
static void         paintbrush_motion      (PaintCore *, GimpDrawable *, double, double, gboolean, int);
static Argument *   paintbrush_invoker     (Argument *);
static Argument *   paintbrush_extended_invoker     (Argument *);
static Argument *   paintbrush_extended_gradient_invoker     (Argument *);


/*  functions  */

static void
paintbrush_gradient_toggle_callback (GtkWidget *widget,
				     gpointer   data)
{
  PaintOptions *options = paintbrush_options;

  static int incremental_save = FALSE;

  tool_options_toggle_update (widget, data);

  if (paintbrush_options->use_gradient)
    {
      incremental_save = options->incremental;
      gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->incremental_w),
				    TRUE);
      gtk_widget_set_sensitive (options->incremental_w, FALSE);
    }
  else
    {
      gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->incremental_w),
				    incremental_save);
      gtk_widget_set_sensitive (options->incremental_w, TRUE);
    }
}

static void
paintbrush_gradient_type_callback (GtkWidget *widget,
				   gpointer   data)
{
  if (paintbrush_options)
    paintbrush_options->gradient_type = (int) data;
}


static void
paintbrush_options_reset (void)
{
  PaintOptions *options = paintbrush_options;

  gtk_adjustment_set_value (GTK_ADJUSTMENT (options->fade_out_w),
			    options->fade_out_d);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->use_gradient_w),
				options->use_gradient_d);
  gtk_adjustment_set_value (GTK_ADJUSTMENT (options->gradient_length_w),
			    options->gradient_length_d);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->gradient_type_w),
				TRUE);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->incremental_w),
				options->incremental_d);
}

static PaintOptions *
paintbrush_options_new (void)
{
  PaintOptions *options;

  GtkWidget *vbox;
  GtkWidget *abox;
  GtkWidget *table;
  GtkWidget *label;
  GtkWidget *scale;
  GSList    *group = NULL;
  GtkWidget *radio_frame;
  GtkWidget *radio_box;
  GtkWidget *radio_button;

  int i;
  char *gradient_types[4] =
  {
    N_("Once Forward"),
    N_("Once Backward"),
    N_("Loop Sawtooth"),
    N_("Loop Triangle")
  };

  /*  the new paint tool options structure  */
  options = (PaintOptions *) g_malloc (sizeof (PaintOptions));
  tool_options_init ((ToolOptions *) options,
		     _("Paintbrush Options"),
		     paintbrush_options_reset);
  options->fade_out        = options->fade_out_d        = 0.0;
  options->incremental     = options->incremental_d     = FALSE;
  options->use_gradient    = options->use_gradient_d    = FALSE;
  options->gradient_length = options->gradient_length_d = 10.0;
  options->gradient_type   = options->gradient_type_d   = 3;
  
  /*  the main vbox  */
  vbox = options->tool_options.main_vbox;

  /*  the fade-out scale  */
  table = gtk_table_new (4, 2, FALSE);
  gtk_table_set_col_spacing (GTK_TABLE (table), 0, 6);
  gtk_table_set_row_spacing (GTK_TABLE (table), 0, 2);
  gtk_table_set_row_spacing (GTK_TABLE (table), 2, 3);
  gtk_box_pack_start (GTK_BOX (vbox), table, FALSE, FALSE, 0);

  label = gtk_label_new (_("Fade Out:"));
  gtk_misc_set_alignment (GTK_MISC (label), 1.0, 1.0);
  gtk_table_attach (GTK_TABLE (table), label, 0, 1, 0, 1,
		    GTK_SHRINK | GTK_FILL, GTK_SHRINK | GTK_FILL, 0, 0);
  gtk_widget_show (label);

  options->fade_out_w =
    gtk_adjustment_new (options->fade_out_d, 0.0, 1000.0, 1.0, 1.0, 0.0);
  scale = gtk_hscale_new (GTK_ADJUSTMENT (options->fade_out_w));
  gtk_table_attach_defaults (GTK_TABLE (table), scale, 1, 2, 0, 1);
  gtk_scale_set_value_pos (GTK_SCALE (scale), GTK_POS_TOP);
  gtk_range_set_update_policy (GTK_RANGE (scale), GTK_UPDATE_DELAYED);
  gtk_signal_connect (GTK_OBJECT (options->fade_out_w), "value_changed",
		      (GtkSignalFunc) tool_options_double_adjustment_update,
		      &options->fade_out);
  gtk_widget_show (scale);

  /*  the use gradient toggle  */
  options->use_gradient_w =
    gtk_check_button_new_with_label (_("Gradient"));
  gtk_table_attach (GTK_TABLE (table), options->use_gradient_w, 0, 1, 1, 2,
		    GTK_SHRINK | GTK_FILL, GTK_SHRINK, 0, 0);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->use_gradient_w),
				options->use_gradient_d);
  gtk_signal_connect (GTK_OBJECT (options->use_gradient_w), "toggled",
		      (GtkSignalFunc) paintbrush_gradient_toggle_callback,
		      &options->use_gradient);
  gtk_widget_show (options->use_gradient_w);

  label = gtk_label_new (_("Length:"));
  gtk_misc_set_alignment (GTK_MISC (label), 1.0, 1.0);
  gtk_table_attach (GTK_TABLE (table), label, 0, 1, 2, 3,
		    GTK_SHRINK | GTK_FILL, GTK_SHRINK | GTK_FILL, 0, 0);
  gtk_widget_show (label);

  /*  the gradient length scale  */
  abox = gtk_alignment_new (0.5, 1.0, 1.0, 0.0);
  gtk_table_attach (GTK_TABLE (table), abox, 1, 2, 1, 3,
		    GTK_EXPAND | GTK_FILL, GTK_SHRINK | GTK_FILL, 0, 0);
  gtk_widget_show (abox);

  options->gradient_length_w =
    gtk_adjustment_new (options->gradient_length_d, 1.0, 50.0, 1.1, 0.1, 0.0);
  scale = gtk_hscale_new (GTK_ADJUSTMENT (options->gradient_length_w));
  gtk_container_add (GTK_CONTAINER (abox), scale);
  gtk_scale_set_value_pos (GTK_SCALE (scale), GTK_POS_TOP);
  gtk_range_set_update_policy (GTK_RANGE (scale), GTK_UPDATE_DELAYED);
  gtk_signal_connect (GTK_OBJECT (options->gradient_length_w), "value_changed",
		      (GtkSignalFunc) tool_options_double_adjustment_update,
		      &options->gradient_length);
  gtk_widget_show (scale);
  gtk_widget_show (table);

   /*  the radio frame and box  */
  radio_frame = gtk_frame_new (_("Gradient Type"));
  gtk_table_attach_defaults (GTK_TABLE (table), radio_frame, 0, 2, 3, 4);

  /*  automatically set the sensitive state of the gradient stuff  */
  gtk_widget_set_sensitive (scale, options->use_gradient_d);
  gtk_widget_set_sensitive (label, options->use_gradient_d);
  gtk_widget_set_sensitive (radio_frame, options->use_gradient_d);
  gtk_object_set_data (GTK_OBJECT (options->use_gradient_w), "set_sensitive",
		       scale);
  gtk_object_set_data (GTK_OBJECT (scale), "set_sensitive",
		       label);
  gtk_object_set_data (GTK_OBJECT (label), "set_sensitive",
		       radio_frame);

  radio_box = gtk_vbox_new (FALSE, 1);
  gtk_container_set_border_width (GTK_CONTAINER (radio_box), 2);
  gtk_container_add (GTK_CONTAINER (radio_frame), radio_box);

    /*  the radio buttons  */
  group = NULL;  
  for (i = 0; i < 4; i++)
    {
      radio_button = gtk_radio_button_new_with_label (group, gradient_types[i]);
      group = gtk_radio_button_group (GTK_RADIO_BUTTON (radio_button));
      gtk_signal_connect (GTK_OBJECT (radio_button), "toggled",
			  (GtkSignalFunc) paintbrush_gradient_type_callback,
			  (void *)((long) i));
      gtk_box_pack_start (GTK_BOX (radio_box), radio_button, FALSE, FALSE, 0);
      gtk_widget_show (radio_button);

      if (i == options->gradient_type_d)
	options->gradient_type_w = radio_button;
    }
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->gradient_type_w),
				TRUE);
  gtk_widget_show (radio_box);
  gtk_widget_show (radio_frame);

  /* the incremental toggle */
  options->incremental_w = gtk_check_button_new_with_label (_("Incremental"));
  gtk_box_pack_start (GTK_BOX (vbox), options->incremental_w, FALSE, FALSE, 0);
  gtk_signal_connect (GTK_OBJECT (options->incremental_w), "toggled",
		      (GtkSignalFunc) tool_options_toggle_update,
		      &options->incremental);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->incremental_w),
				options->incremental_d);
  gtk_widget_show (options->incremental_w);
  
  return options;
}


#define USE_SPEEDSHOP_CALIPERS 0
#define TIMED_BRUSH 0

#if USE_SPEEDSHOP_CALIPERS
#include <SpeedShop/api.h>
#endif

void *
paintbrush_paint_func (PaintCore *paint_core,
		       GimpDrawable *drawable,
		       int        state)
{
#if TIMED_BRUSH
  static GTimer *timer;
#endif
  switch (state)
    {
    case INIT_PAINT :
#if TIMED_BRUSH
      timer = g_timer_new();
      g_timer_start(timer);
#if USE_SPEEDSHOP_CALIPERS
      ssrt_caliper_point(0, "Painting");
#endif /* USE_SPEEDSHOP_CALIPERS */
#endif /* TIMED_BRUSH */
      break;

    case MOTION_PAINT :
      paintbrush_motion (paint_core, drawable, 
			 paintbrush_options->fade_out, 
			 paintbrush_options->use_gradient ? 
			 exp(paintbrush_options->gradient_length/10) : 0,
			 paintbrush_options->incremental,
			 paintbrush_options->gradient_type);
      break;

    case FINISH_PAINT :
#if TIMED_BRUSH
#if USE_SPEEDSHOP_CALIPERS
      ssrt_caliper_point(0, "Not Painting Anymore");
#endif /* USE_SPEEDSHOP_CALIPERS */
      g_timer_stop(timer);
      printf("painting took %f:\n", g_timer_elapsed(timer, NULL));
      g_timer_destroy(timer);
#endif /* TIMED_BRUSH */
      break;

    default :
      break;
    }

  return NULL;
}


Tool *
tools_new_paintbrush ()
{
  Tool * tool;
  PaintCore * private;

  /*  The tool options  */
  if (! paintbrush_options)
    {
      paintbrush_options = paintbrush_options_new ();
      tools_register (PAINTBRUSH, (ToolOptions *) paintbrush_options);
    }

  tool = paint_core_new (PAINTBRUSH);

  private = (PaintCore *) tool->private;
  private->paint_func = paintbrush_paint_func;

  return tool;
}


void
tools_free_paintbrush (Tool *tool)
{
  paint_core_free (tool);
}


static void
paintbrush_motion (PaintCore *paint_core,
		   GimpDrawable *drawable,
		   double     fade_out,
		   double     gradient_length,
		   gboolean   incremental,
		   int gradient_type)
{
  GImage *gimage;
  TempBuf * area;
  double x, paint_left;
  double position;
  unsigned char local_blend = OPAQUE_OPACITY;
  unsigned char temp_blend = OPAQUE_OPACITY;
  unsigned char col[MAX_CHANNELS];
  double r,g,b,a;
  int mode;

  position = 0.0;
  if (! (gimage = drawable_gimage (drawable)))
    return;

  gimage_get_foreground (gimage, drawable, col);

  /*  Get a region which can be used to p\\aint to  */
  if (! (area = paint_core_get_paint_area (paint_core, drawable)))
    return;

  /*  factor in the fade out value  */
  if (fade_out)
    {
      /*  Model the amount of paint left as a gaussian curve  */
      x = ((double) paint_core->distance / fade_out);
      paint_left = exp (- x * x * 0.5);

      local_blend = (int) (255 * paint_left);
    }

  if (local_blend)
    {
      /*  set the alpha channel  */
      col[area->bytes - 1] = OPAQUE_OPACITY;
      temp_blend = local_blend;
      
      /* hard core to mode LOOP_TRIANGLE */
      /* need to maek a gui to handle this */
      mode = gradient_type;

      if(gradient_length)
	{
	  paint_core_get_color_from_gradient (paint_core, gradient_length, &r,&g,&b,&a,mode);
	  r = r * 255.0;
	  g = g * 255.0;
	  b = b * 255.0;
	  a = a * 255.0;
	  temp_blend =  (gint)((a * local_blend)/255);
	  col[0] = (gint)r;
	  col[1] = (gint)g;
	  col[2] = (gint)b;
	  /* always use incremental mode with gradients */
	  /* make the gui cool later */
	  incremental = INCREMENTAL;
	}
  /* just leave this because I know as soon as i delete it i'll find a bug */
      /*          printf("temp_blend: %u grad_len: %f distance: %f \n",temp_blend, gradient_length, distance); */ 
	
      /*  color the pixels  */
      color_pixels (temp_buf_data (area), col,
		    area->width * area->height, area->bytes);

      /*  paste the newly painted canvas to the gimage which is being worked on  */
      paint_core_paste_canvas (paint_core, drawable, temp_blend,
			       (int) (gimp_brush_get_opacity () * 255),
			       gimp_brush_get_paint_mode (), PRESSURE, 
			       incremental ? INCREMENTAL : CONSTANT);
    }
}


static void *
paintbrush_non_gui_paint_func (PaintCore *paint_core,
			       GimpDrawable *drawable,
			       int        state)
{	
  paintbrush_motion (paint_core, drawable, non_gui_fade_out,non_gui_gradient_length,  non_gui_incremental, non_gui_gradient_type);

  return NULL;
}


/*  The paintbrush procedure definition  */
ProcArg paintbrush_args[] =
{
  { PDB_DRAWABLE,
    "drawable",
    "the drawable"
  },
  { PDB_FLOAT,
    "fade_out",
    "fade out parameter: fade_out > 0"
  },
  { PDB_INT32,
    "num_strokes",
    "number of stroke control points (count each coordinate as 2 points)"
  },
  { PDB_FLOATARRAY,
    "strokes",
    "array of stroke coordinates: {s1.x, s1.y, s2.x, s2.y, ..., sn.x, sn.y}"
  }
};

ProcArg paintbrush_extended_args[] =
{
  { PDB_DRAWABLE,
    "drawable",
    "the drawable"
  },
  { PDB_FLOAT,
    "fade_out",
    "fade out parameter: fade_out > 0"
  },
  { PDB_INT32,
    "num_strokes",
    "number of stroke control points (count each coordinate as 2 points)"
  },
  { PDB_FLOATARRAY,
    "strokes",
    "array of stroke coordinates: {s1.x, s1.y, s2.x, s2.y, ..., sn.x, sn.y}"
  },
  { PDB_INT32,
    "method",
    "CONTINUOUS(0) or INCREMENTAL(1)"
  }
};

ProcArg paintbrush_extended_gradient_args[] =
{
  { PDB_DRAWABLE,
    "drawable",
    "the drawable"
  },
  { PDB_FLOAT,
    "fade_out",
    "fade out parameter: fade_out > 0"
  },
  { PDB_FLOAT,
    "gradient_length",
    "Length of gradient to draw: gradient_lengtth >0"
  },
  { PDB_INT32,
    "num_strokes",
    "number of stroke control points (count each coordinate as 2 points)"
  },
  { PDB_FLOATARRAY,
    "strokes",
    "array of stroke coordinates: {s1.x, s1.y, s2.x, s2.y, ..., sn.x, sn.y}"
  },
  { PDB_INT32,
    "method",
    "CONTINUOUS(0) or INCREMENTAL(1)"
  }
};


ProcRecord paintbrush_proc =
{
  "gimp_paintbrush",
  "Paint in the current brush with optional fade out parameter",
  "This tool is the standard paintbrush.  It draws linearly interpolated lines through the specified stroke coordinates.  It operates on the specified drawable in the foreground color with the active brush.  The \"fade_out\" parameter is measured in pixels and allows the brush stroke to linearly fall off.  The pressure is set to the maximum at the beginning of the stroke.  As the distance of the stroke nears the fade_out value, the pressure will approach zero.",
  "Spencer Kimball & Peter Mattis",
  "Spencer Kimball & Peter Mattis",
  "1995-1996",
  PDB_INTERNAL,

  /*  Input arguments  */
  4,
  paintbrush_args,

  /*  Output arguments  */
  0,
  NULL,

  /*  Exec method  */
  { { paintbrush_invoker } },
};

ProcRecord paintbrush_extended_proc =
{
  "gimp_paintbrush_extended",
  "Paint in the current brush with optional fade out parameter",
  "This tool is the standard paintbrush.  It draws linearly interpolated lines through the specified stroke coordinates.  It operates on the specified drawable in the foreground color with the active brush.  The \"fade_out\" parameter is measured in pixels and allows the brush stroke to linearly fall off.  The pressure is set to the maximum at the beginning of the stroke.  As the distance of the stroke nears the fade_out value, the pressure will approach zero.",
  "Spencer Kimball & Peter Mattis",
  "Spencer Kimball & Peter Mattis",
  "1995-1996",
  PDB_INTERNAL,

  /*  Input arguments  */
  5,
  paintbrush_extended_args,

  /*  Output arguments  */
  0,
  NULL,

  /*  Exec method  */
  { { paintbrush_extended_invoker } },
};

ProcRecord paintbrush_extended_gradient_proc =
{
  "gimp_paintbrush_extended_gradient",
  "Paint in the current brush with optional fade out parameter and a pull colors from a gradient",
  "This tool is the gradient paintbrush.  It draws linearly interpolated lines through the specified stroke coordinates.  It operates on the specified drawable with colors drawn from the current active gradient with the active brush.  The \"fade_out\" parameter is measured in pixels and allows the brush stroke to linearly fall off.  The pressure is set to the maximum at the beginning of the stroke.  As the distance of the stroke nears the fade_out value, the pressure will approach zero. The gradient_length is the distance to spread the gradient over. It is measured in pixels.",
  "Spencer Kimball & Peter Mattis",
  "Spencer Kimball & Peter Mattis",
  "1995-1996",
  PDB_INTERNAL,

  /*  Input arguments  */
  6,
  paintbrush_extended_gradient_args,

  /*  Output arguments  */
  0,
  NULL,

  /*  Exec method  */
  { { paintbrush_extended_gradient_invoker } },
};

static Argument *
paintbrush_invoker (Argument *args)
{
  int success = TRUE;
  GImage *gimage;
  GimpDrawable *drawable;
  int num_strokes;
  double *stroke_array;
  int int_value;
  double fp_value;
  int i;

  drawable = NULL;
  num_strokes = 0;

  /*  the drawable  */
  if (success)
    {
      int_value = args[0].value.pdb_int;
      drawable = drawable_get_ID (int_value);
      if (drawable == NULL)                                        
        success = FALSE;
      else
        gimage = drawable_gimage (drawable);
    }
  /*  fade out  */
  if (success)
    {
      fp_value = args[1].value.pdb_float;
      if (fp_value >= 0.0)
	non_gui_fade_out = fp_value;
      else
	success = FALSE;
    }
  /* FIXME FIXME FIXME */
  /* but we need to change the pdb call to gimp_paintbrush...ouch!! */
  /* should this be enough to do this without breaking PDB? */
  if (success)
    {
      non_gui_gradient_length = 0.0;
      non_gui_gradient_type = 0;
    }
  /*  num strokes  */
  if (success)
    {
      int_value = args[2].value.pdb_int;
      if (int_value > 0)
	num_strokes = int_value / 2;
      else
	success = FALSE;
    }

  /*  point array  */
  if (success)
    stroke_array = (double *) args[3].value.pdb_pointer;

  if (success)
    /*  init the paint core  */
    success = paint_core_init (&non_gui_paint_core, drawable,
			       stroke_array[0], stroke_array[1]);

  if (success)
    {
      non_gui_incremental = 0;
      /*  set the paint core's paint func  */
      non_gui_paint_core.paint_func = paintbrush_non_gui_paint_func;

      non_gui_paint_core.startx = non_gui_paint_core.lastx = stroke_array[0];
      non_gui_paint_core.starty = non_gui_paint_core.lasty = stroke_array[1];

      if (num_strokes == 1)
	paintbrush_non_gui_paint_func (&non_gui_paint_core, drawable, 0);

      for (i = 1; i < num_strokes; i++)
	{
	  non_gui_paint_core.curx = stroke_array[i * 2 + 0];
	  non_gui_paint_core.cury = stroke_array[i * 2 + 1];

	  paint_core_interpolate (&non_gui_paint_core, drawable);

	  non_gui_paint_core.lastx = non_gui_paint_core.curx;
	  non_gui_paint_core.lasty = non_gui_paint_core.cury;
	}

      /*  finish the painting  */
      paint_core_finish (&non_gui_paint_core, drawable, -1);

      /*  cleanup  */
      paint_core_cleanup ();
    }

  return procedural_db_return_args (&paintbrush_proc, success);
}


static Argument *
paintbrush_extended_invoker (Argument *args)
{
  int success = TRUE;
  GImage *gimage;
  GimpDrawable *drawable;
  int num_strokes;
  double *stroke_array;
  int int_value;
  double fp_value;
  int i;

  drawable = NULL;
  num_strokes = 0;

  /*  the drawable  */
  if (success)
    {
      int_value = args[0].value.pdb_int;
      drawable = drawable_get_ID (int_value);
      if (drawable == NULL)                                        
        success = FALSE;
      else
        gimage = drawable_gimage (drawable);
    }
  /*  fade out  */
  if (success)
    {
      fp_value = args[1].value.pdb_float;
      if (fp_value >= 0.0)
	non_gui_fade_out = fp_value;
      else
	success = FALSE;
    }
  /* FIXME FIXME FIXME */
  /* but we need to change the pdb call to gimp_paintbrush...ouch!! */
  /* should this be enough to do this without breaking PDB? */
  if (success)
    {
      non_gui_gradient_length = 0.0;
      non_gui_gradient_type = 3;
    }
  /*  num strokes  */
  if (success)
    {
      int_value = args[2].value.pdb_int;
      if (int_value > 0)
	num_strokes = int_value / 2;
      else
	success = FALSE;
    }

  /*  point array  */
  if (success)
    stroke_array = (double *) args[3].value.pdb_pointer;

  if (success)
    /*  init the paint core  */
    success = paint_core_init (&non_gui_paint_core, drawable,
			       stroke_array[0], stroke_array[1]);

  if (success)
    {
      non_gui_incremental = args[4].value.pdb_int;
      /*  set the paint core's paint func  */
      non_gui_paint_core.paint_func = paintbrush_non_gui_paint_func;

      non_gui_paint_core.startx = non_gui_paint_core.lastx = stroke_array[0];
      non_gui_paint_core.starty = non_gui_paint_core.lasty = stroke_array[1];

      if (num_strokes == 1)
	paintbrush_non_gui_paint_func (&non_gui_paint_core, drawable, 0);

      for (i = 1; i < num_strokes; i++)
	{
	  non_gui_paint_core.curx = stroke_array[i * 2 + 0];
	  non_gui_paint_core.cury = stroke_array[i * 2 + 1];

	  paint_core_interpolate (&non_gui_paint_core, drawable);

	  non_gui_paint_core.lastx = non_gui_paint_core.curx;
	  non_gui_paint_core.lasty = non_gui_paint_core.cury;
	}

      /*  finish the painting  */
      paint_core_finish (&non_gui_paint_core, drawable, -1);

      /*  cleanup  */
      paint_core_cleanup ();
    }

  return procedural_db_return_args (&paintbrush_extended_proc, success);
}








static Argument *
paintbrush_extended_gradient_invoker (Argument *args)
{
  int success = TRUE;
  GImage *gimage;
  GimpDrawable *drawable;
  int num_strokes;
  double *stroke_array;
  int int_value;
  double fp_value;
  int i;

  drawable = NULL;
  num_strokes = 0;

  /*  the drawable  */
  if (success)
    {
      int_value = args[0].value.pdb_int;
      drawable = drawable_get_ID (int_value);
      if (drawable == NULL)                                        
        success = FALSE;
      else
        gimage = drawable_gimage (drawable);
    }
  /*  fade out  */
  if (success)
    {
      fp_value = args[1].value.pdb_float;
      if (fp_value >= 0.0)
	non_gui_fade_out = fp_value;
      else
	success = FALSE;
    }
  /* gradient length */
  if(success)
    {
      fp_value = args[2].value.pdb_float;
      if(fp_value >= 0.0)
	 non_gui_gradient_length = fp_value;
      else
	success = FALSE;
    }
  /*  num strokes  */
  if (success)
    {
      int_value = args[3].value.pdb_int;
      if (int_value > 0)
	num_strokes = int_value / 2;
      else
	success = FALSE;
    }

  /*  point array  */
  if (success)
    stroke_array = (double *) args[4].value.pdb_pointer;

  if (success)
    /*  init the paint core  */
    success = paint_core_init (&non_gui_paint_core, drawable,
			       stroke_array[0], stroke_array[1]);

  if (success)
    {
      non_gui_incremental = args[5].value.pdb_int;
      /*  set the paint core's paint func  */
      non_gui_paint_core.paint_func = paintbrush_non_gui_paint_func;

      non_gui_paint_core.startx = non_gui_paint_core.lastx = stroke_array[0];
      non_gui_paint_core.starty = non_gui_paint_core.lasty = stroke_array[1];

      if (num_strokes == 1)
	paintbrush_non_gui_paint_func (&non_gui_paint_core, drawable, 0);

      for (i = 1; i < num_strokes; i++)
	{
	  non_gui_paint_core.curx = stroke_array[i * 2 + 0];
	  non_gui_paint_core.cury = stroke_array[i * 2 + 1];

	  paint_core_interpolate (&non_gui_paint_core, drawable);

	  non_gui_paint_core.lastx = non_gui_paint_core.curx;
	  non_gui_paint_core.lasty = non_gui_paint_core.cury;
	}

      /*  finish the painting  */
      paint_core_finish (&non_gui_paint_core, drawable, -1);

      /*  cleanup  */
      paint_core_cleanup ();
    }

  return procedural_db_return_args (&paintbrush_extended_gradient_proc, success);
}