/* 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 "config.h"

#include <stdlib.h>
#include <stdio.h>

#include "gdk/gdkkeysyms.h"

#include "appenv.h"
#include "drawable.h"
#include "errors.h"
#include "smudge.h"
#include "gdisplay.h"
#include "gimplut.h"
#include "gimpui.h"
#include "paint_funcs.h"
#include "paint_core.h"
#include "paint_options.h"
#include "selection.h"
#include "tools.h"
#include "gimage.h"

#include "libgimp/gimpintl.h"
#include "libgimp/gimpmath.h"


/* default defines */

#define SMUDGE_DEFAULT_RATE   50.0

/*  the smudge structures  */

typedef struct _SmudgeOptions SmudgeOptions;

struct _SmudgeOptions
{
  PaintOptions  paint_options;

  gdouble       rate;
  gdouble       rate_d;
  GtkObject    *rate_w;
};

static PixelRegion  accumPR;
static guchar      *accum_data;

/*  the smudge tool options  */
static SmudgeOptions * smudge_options = NULL;

/*  local variables */
static gdouble  non_gui_rate;

/*  function prototypes */
static void      smudge_motion     (PaintCore *, PaintPressureOptions *,
				    gdouble, GimpDrawable *);
static gboolean  smudge_init       (PaintCore *, GimpDrawable *);
static void      smudge_finish     (PaintCore *, GimpDrawable *);

static void      smudge_nonclipped_painthit_coords (PaintCore *paint_core,
						    gint      *x,
						    gint      *y, 
						    gint      *w,
						    gint      *h);
static void      smudge_allocate_accum_buffer      (gint       w,
						    gint       h, 
						    gint       bytes,
						    guchar    *do_fill);

static void
smudge_options_reset (void)
{
  SmudgeOptions *options = smudge_options;

  paint_options_reset ((PaintOptions *) options);

  gtk_adjustment_set_value (GTK_ADJUSTMENT (options->rate_w), options->rate_d);
}

static SmudgeOptions *
smudge_options_new (void)
{
  SmudgeOptions *options;

  GtkWidget *vbox;
  GtkWidget *hbox;
  GtkWidget *label;
  GtkWidget *scale;

  /*  the new smudge tool options structure  */
  options = g_new (SmudgeOptions, 1);
  paint_options_init ((PaintOptions *) options,
		      SMUDGE,
		      smudge_options_reset);

  options->rate = options->rate_d = SMUDGE_DEFAULT_RATE;

  /*  the main vbox  */
  vbox = ((ToolOptions *) options)->main_vbox;

  /*  the rate scale  */
  hbox = gtk_hbox_new (FALSE, 4);
  gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, FALSE, 0);

  label = gtk_label_new (_("Rate:"));
  gtk_misc_set_alignment (GTK_MISC (label), 1.0, 1.0);
  gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
  gtk_widget_show (label);

  options->rate_w =
    gtk_adjustment_new (options->rate_d, 0.0, 100.0, 1.0, 1.0, 0.0);
  scale = gtk_hscale_new (GTK_ADJUSTMENT (options->rate_w));
  gtk_box_pack_start (GTK_BOX (hbox), scale, TRUE, TRUE, 0);
  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->rate_w), "value_changed",
		      GTK_SIGNAL_FUNC (gimp_double_adjustment_update),
		      &options->rate);
  gtk_widget_show (scale);
  gtk_widget_show (hbox);

  return options;
}

void *
smudge_paint_func (PaintCore    *paint_core,
		   GimpDrawable *drawable,
		   int           state)
{
  /* initialization fails if the user starts outside the drawable */
  static gboolean initialized = FALSE;

  switch (state)
    {
    case INIT_PAINT:
      initialized = smudge_init (paint_core, drawable);
      break;
    case MOTION_PAINT:
      if (!initialized)
	initialized = smudge_init (paint_core, drawable);
      if (initialized)
	smudge_motion (paint_core, smudge_options->paint_options.pressure_options,
		       smudge_options->rate, drawable);
      break;
    case FINISH_PAINT:
      smudge_finish (paint_core, drawable);
      initialized = FALSE;
      break;
    }

  return NULL;
}

static void
smudge_finish (PaintCore    *paint_core,
	       GimpDrawable *drawable)
{
  if (accum_data)
    {
      g_free (accum_data);
      accum_data = NULL;
    }
}

static void 
smudge_nonclipped_painthit_coords (PaintCore *paint_core,
				   gint      *x, 
				   gint      *y, 
				   gint      *w, 
				   gint      *h)
{
  /* Note: these are the brush mask size plus a border of 1 pixel */
  *x = (gint) paint_core->curx - paint_core->brush->mask->width/2 - 1;
  *y = (gint) paint_core->cury - paint_core->brush->mask->height/2 - 1;
  *w = paint_core->brush->mask->width + 2;
  *h = paint_core->brush->mask->height + 2;
}

static gboolean
smudge_init (PaintCore    *paint_core,
	     GimpDrawable *drawable)
{
  GImage *gimage;
  TempBuf *area;
  PixelRegion  srcPR;
  gint x, y, w, h;
  gint was_clipped;
  guchar *do_fill = NULL;

  if (! (gimage = drawable_gimage (drawable)))
    return FALSE;

  /*  If the image type is indexed, don't smudge  */
  if ((drawable_type (drawable) == INDEXED_GIMAGE) ||
      (drawable_type (drawable) == INDEXEDA_GIMAGE))
    return FALSE;

  area = paint_core_get_paint_area (paint_core, drawable, 1.0);

  if (!area) 
    return FALSE;
  
  /*  adjust the x and y coordinates to the upper left corner of the brush  */
  smudge_nonclipped_painthit_coords (paint_core, &x, &y, &w, &h);
  
  if (x != area->x || y != area->y || w != area->width || h != area->height)
    was_clipped = TRUE;
  else 
    was_clipped = FALSE;

  /* When clipped, accum_data may contain pixels that map to
     off-canvas pixels of the under-the-brush image, particulary
     when the brush image contains an edge or corner of the
     image. These off-canvas pixels are not a part of the current
     composite, but may be composited in later generations. do_fill
     contains a copy of the color of the pixel at the center of the
     brush; assumed this is a reasonable choice for off- canvas pixels
     that may enter into the blend */

  if (was_clipped)
    do_fill = gimp_drawable_get_color_at (drawable,
                 CLAMP ((gint) paint_core->curx, 0, gimp_drawable_width (drawable) - 1),
                 CLAMP ((gint) paint_core->cury, 0, gimp_drawable_height (drawable) - 1));
  
  smudge_allocate_accum_buffer (w, h, gimp_drawable_bytes (drawable), do_fill);

  accumPR.x = area->x - x; 
  accumPR.y = area->y - y;
  accumPR.w = area->width;
  accumPR.h = area->height;
  accumPR.rowstride = accumPR.bytes * w; 
  accumPR.data = accum_data 
	+ accumPR.rowstride * accumPR.y 
	+ accumPR.x * accumPR.bytes;

  pixel_region_init (&srcPR, drawable_data (drawable), 
	    area->x, area->y, area->width, area->height, FALSE);

  /* copy the region under the original painthit. */
  copy_region (&srcPR, &accumPR);

  accumPR.x = area->x - x; 
  accumPR.y = area->y - y;
  accumPR.w = area->width;
  accumPR.h = area->height;
  accumPR.rowstride = accumPR.bytes * w;
  accumPR.data = accum_data
	+ accumPR.rowstride * accumPR.y 
	+ accumPR.x * accumPR.bytes;

  if (do_fill) 
    g_free(do_fill);

  return TRUE;
}

static void
smudge_allocate_accum_buffer (gint    w, 
			      gint    h, 
			      gint    bytes,
			      guchar *do_fill)
{ 
  /*  Allocate the accumulation buffer */
  accumPR.bytes = bytes;
  accum_data = g_malloc (w * h * bytes);
 
  if (do_fill != NULL)
    {
      /* guchar color[3] = {0,0,0}; */
      accumPR.x = 0; 
      accumPR.y = 0;
      accumPR.w = w;
      accumPR.h = h;
      accumPR.rowstride = accumPR.bytes * w;
      accumPR.data = accum_data;
      color_region (&accumPR, (const guchar*)do_fill);
    }
}

Tool *
tools_new_smudge (void)
{
  Tool * tool;
  PaintCore * private;

  /*  The tool options  */
  if (! smudge_options)
    {
      smudge_options = smudge_options_new ();
      tools_register (SMUDGE, (ToolOptions *) smudge_options);

      /*  press all default buttons  */
      smudge_options_reset ();
    }

  tool = paint_core_new (SMUDGE);
  /*tool->modifier_key_func = smudge_modifier_key_func;*/

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

  return tool;
}

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

static void
smudge_motion (PaintCore            *paint_core,
	       PaintPressureOptions *pressure_options,
	       gdouble               smudge_rate,
	       GimpDrawable         *drawable)
{
  GImage *gimage;
  TempBuf * area;
  PixelRegion srcPR, destPR, tempPR;
  gdouble rate;
  gint opacity;
  gint x,y,w,h;

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

  /*  If the image type is indexed, don't smudge  */
  if ((drawable_type (drawable) == INDEXED_GIMAGE) ||
      (drawable_type (drawable) == INDEXEDA_GIMAGE))
    return;

  smudge_nonclipped_painthit_coords (paint_core, &x, &y, &w, &h);

  /*  Get the paint area */
  /*  Smudge won't scale!  */
  if (! (area = paint_core_get_paint_area (paint_core, drawable, 1.0)))
    return;

  /* srcPR will be the pixels under the current painthit from 
     the drawable*/

  pixel_region_init (&srcPR, drawable_data (drawable), 
		     area->x, area->y, area->width, area->height, FALSE);

  /* Enable pressure sensitive rate */
  if (pressure_options->rate)
    rate = MIN (smudge_rate / 100.0 * paint_core->curpressure * 2.0, 1.0);
  else
    rate = smudge_rate / 100.0;

  /* The tempPR will be the built up buffer (for smudge) */ 
  tempPR.bytes = accumPR.bytes;
  tempPR.rowstride = accumPR.rowstride;
  tempPR.x = area->x - x; 
  tempPR.y = area->y - y;
  tempPR.w = area->width;
  tempPR.h = area->height;
  tempPR.data = accum_data +
    tempPR.rowstride * tempPR.y + tempPR.x * tempPR.bytes;

  /* The dest will be the paint area we got above (= canvas_buf) */    

  destPR.bytes = area->bytes;                                     
  destPR.x = 0; destPR.y = 0;                                     
  destPR.w = area->width;                                         
  destPR.h = area->height;                                        
  destPR.rowstride = area->width * area->bytes;                  
  destPR.data = temp_buf_data (area); 

  /*  
     Smudge uses the buffer Accum.
     For each successive painthit Accum is built like this
	Accum =  rate*Accum  + (1-rate)*I.
     where I is the pixels under the current painthit. 
     Then the paint area (canvas_buf) is built as 
	(Accum,1) (if no alpha),
  */

  blend_region (&srcPR, &tempPR, &tempPR, ROUND (rate * 255.0));

  /* re-init the tempPR */

  tempPR.bytes = accumPR.bytes;
  tempPR.rowstride = accumPR.rowstride;
  tempPR.x = area->x - x; 
  tempPR.y = area->y - y;
  tempPR.w = area->width;
  tempPR.h = area->height;
  tempPR.data = accum_data 
	+ tempPR.rowstride * tempPR.y 
	+ tempPR.x * tempPR.bytes;

  if (!drawable_has_alpha (drawable))                             
    add_alpha_region (&tempPR, &destPR);                          
  else                                                            
    copy_region(&tempPR, &destPR);

  opacity = 255 * gimp_context_get_opacity (NULL);
  if (pressure_options->opacity)
    opacity = opacity * 2.0 * paint_core->curpressure;

  /*Replace the newly made paint area to the gimage*/ 
  paint_core_replace_canvas (paint_core, drawable, 
			     MIN (opacity, 255),
			     OPAQUE_OPACITY, 
			     pressure_options->pressure ? PRESSURE : SOFT,
			     1.0, INCREMENTAL);
}

static void *
smudge_non_gui_paint_func (PaintCore    *paint_core,
			   GimpDrawable *drawable,
			   int           state)
{
  smudge_motion (paint_core, &non_gui_pressure_options, non_gui_rate, drawable);

  return NULL;
}

gboolean
smudge_non_gui_default (GimpDrawable *drawable,
			int           num_strokes,
			double       *stroke_array)
{
  gdouble rate = SMUDGE_DEFAULT_RATE;
  SmudgeOptions *options = smudge_options;

  if (options)
    rate = options->rate;

  return smudge_non_gui (drawable, rate, num_strokes, stroke_array);
}

gboolean
smudge_non_gui (GimpDrawable *drawable,
		gdouble       rate,
		int           num_strokes,
		double       *stroke_array)
{
  gint i;

  if (paint_core_init (&non_gui_paint_core, drawable,
		       stroke_array[0], stroke_array[1]))
    {
      smudge_init (&non_gui_paint_core, drawable);

      /* Set the paint core's paint func */
      non_gui_paint_core.paint_func = smudge_non_gui_paint_func;

      non_gui_rate = rate;

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

      smudge_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 ();
      smudge_finish (&non_gui_paint_core, drawable);
      return TRUE;
    }
  else
    return FALSE;
}
