/*
 * This is a plugin for the GIMP.
 *
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 * Copyright (C) 1996 Torsten Martinsen
 *
 * 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.
 *
 * $Id$
 */

/*
 * This filter adds random noise to an image.
 * The amount of noise can be set individually for each RGB channel.
 * This filter does not operate on indexed images.
 *
 * May 2000 tim copperfield [timecop@japan.co.jp]
 * Added dynamic preview.
 *
 * alt@gimp.org. Fixed previews so they handle alpha channels correctly.
 */

#include "config.h"

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

#include <gtk/gtk.h>

#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>

#include "libgimp/stdplugins-intl.h"


#define SCALE_WIDTH      125
#define TILE_CACHE_SIZE  16

typedef struct
{
  gint    independent;
  gdouble noise[4];     /*  per channel  */
} NoisifyVals;

typedef struct
{
  gint       channels;
  GtkObject *channel_adj[4];
  gint       run;
} NoisifyInterface;

/* Declare local functions.
 */
static void       query  (void);
static void       run    (gchar      *name,
			  gint        nparams,
			  GimpParam  *param,
			  gint       *nreturn_vals,
			  GimpParam **return_vals);

static void       noisify (GimpDrawable *drawable,
                           gboolean      preview_mode);
static gdouble    gauss   (GRand *gr);

static gint       noisify_dialog                   (GimpDrawable *drawable, 
						    gint           channels);
static void       noisify_ok_callback              (GtkWidget     *widget,
						    gpointer       data);
static void       noisify_double_adjustment_update (GtkAdjustment *adjustment,
						    gpointer       data);

GimpPlugInInfo PLUG_IN_INFO =
{
  NULL,  /* init_proc */
  NULL,  /* quit_proc */
  query, /* query_proc */
  run,   /* run_proc */
};

static NoisifyVals nvals =
{
  TRUE,
  { 0.20, 0.20, 0.20, 0.20 }
};

static NoisifyInterface noise_int =
{
  0,
  { NULL, NULL, NULL, NULL },
  FALSE     /* run */
};

static GimpRunMode       run_mode;
static GimpFixMePreview *preview;

MAIN ()

static void
query (void)
{
  static GimpParamDef args[] =
  {
    { GIMP_PDB_INT32, "run_mode", "Interactive, non-interactive" },
    { GIMP_PDB_IMAGE, "image", "Input image (unused)" },
    { GIMP_PDB_DRAWABLE, "drawable", "Input drawable" },
    { GIMP_PDB_INT32, "independent", "Noise in channels independent" },
    { GIMP_PDB_FLOAT, "noise_1", "Noise in the first channel (red, gray)" },
    { GIMP_PDB_FLOAT, "noise_2", "Noise in the second channel (green, gray_alpha)" },
    { GIMP_PDB_FLOAT, "noise_3", "Noise in the third channel (blue)" },
    { GIMP_PDB_FLOAT, "noise_4", "Noise in the fourth channel (alpha)" }
  };

  gimp_install_procedure ("plug_in_noisify",
			  "Adds random noise to a drawable's channels",
			  "More here later",
			  "Torsten Martinsen",
			  "Torsten Martinsen",
			  "May 2000",
			  N_("<Image>/Filters/Noise/Noisify..."),
			  "RGB*, GRAY*",
			  GIMP_PLUGIN,
			  G_N_ELEMENTS (args), 0,
			  args, NULL);
}

static void
run (gchar      *name,
     gint        nparams,
     GimpParam  *param,
     gint       *nreturn_vals,
     GimpParam **return_vals)
{
  static GimpParam   values[1];
  GimpDrawable      *drawable;
  GimpPDBStatusType  status = GIMP_PDB_SUCCESS;

  run_mode = param[0].data.d_int32;

  *nreturn_vals = 1;
  *return_vals  = values;

  values[0].type          = GIMP_PDB_STATUS;
  values[0].data.d_status = status;

  /*  Get the specified drawable  */
  drawable = gimp_drawable_get (param[2].data.d_drawable);

  switch (run_mode)
    {
    case GIMP_RUN_INTERACTIVE:
      INIT_I18N_UI();
      /*  Possibly retrieve data  */
      gimp_get_data ("plug_in_noisify", &nvals);

      /*  First acquire information with a dialog  */
      if (! noisify_dialog (drawable, drawable->bpp))
	{
	  gimp_drawable_detach (drawable);
	  return;
	}
      break;

    case GIMP_RUN_NONINTERACTIVE:
      INIT_I18N();
      /*  Make sure all the arguments are there!  */
      if (nparams != 8)
	{
	  status = GIMP_PDB_CALLING_ERROR;
	}
      else
	{
	  nvals.independent = param[3].data.d_int32 ? TRUE : FALSE;
	  nvals.noise[0]    = param[4].data.d_float;
	  nvals.noise[1]    = param[5].data.d_float;
	  nvals.noise[2]    = param[6].data.d_float;
	  nvals.noise[3]    = param[7].data.d_float;
	}
      break;

    case GIMP_RUN_WITH_LAST_VALS:
      INIT_I18N();
      /*  Possibly retrieve data  */
      gimp_get_data ("plug_in_noisify", &nvals);
      break;

    default:
      break;
    }

  /*  Make sure that the drawable is gray or RGB color  */
  if (gimp_drawable_is_rgb (drawable->drawable_id) ||
      gimp_drawable_is_gray (drawable->drawable_id))
    {
      gimp_progress_init (_("Adding Noise..."));
      gimp_tile_cache_ntiles (TILE_CACHE_SIZE);

      /*  compute the luminosity which exceeds the luminosity threshold  */
      noisify (drawable, FALSE);

      if (run_mode != GIMP_RUN_NONINTERACTIVE)
	gimp_displays_flush ();

      /*  Store data  */
      if (run_mode == GIMP_RUN_INTERACTIVE) {
	gimp_set_data ("plug_in_noisify", &nvals, sizeof (NoisifyVals));
      }
    }
  else
    {
      /* gimp_message ("blur: cannot operate on indexed color images"); ??? BLUR ??? */
      status = GIMP_PDB_EXECUTION_ERROR;
    }

  values[0].data.d_status = status;

  gimp_drawable_detach (drawable);
}

static void 
noisify_func (guchar *src, guchar *dest, gint bpp, GRand *gr)
{
  gint noise = 0, b;

  if (!nvals.independent)
    noise = (gint) (nvals.noise[0] * gauss (gr) * 127);
  
  for (b = 0; b < bpp; b++)
    {
      if (nvals.noise[b] > 0.0)
	{
	  gint p;

          if (nvals.independent)
	    noise = (gint) (nvals.noise[b] * gauss (gr) * 127);

	  p = src[b] + noise;
	  dest[b] = CLAMP0255 (p);
	}
      else
        {
          dest[b] = src[b];
        }
    }
}

static void
noisify (GimpDrawable *drawable, 
	 gboolean   preview_mode)
{
  GRand *gr;

  gr = g_rand_new ();

  if (preview_mode) 
    {
      guchar *src, *dest, *dest_data;
      gint width, height, row_stride;
      gint row, col;
      gint bpp;

      width = preview->width;
      height = preview->height;
      bpp = preview->bpp;
      row_stride = preview->rowstride;

      dest_data = g_malloc (row_stride);

      for (row = 0; row < height; row++)
	{
	  src  = preview->cache + row * row_stride;
	  dest = dest_data;

	  for (col = 0; col < width; col++)
	    {
	      noisify_func (src, dest, bpp, gr);
	      src += bpp;
	      dest += bpp;
	    }

	  gimp_fixme_preview_do_row(preview, row, width, dest_data);
	}

      g_free (dest_data);
      gtk_widget_queue_draw (preview->widget);
    } 
  else 
    {
      gimp_rgn_iterate2 (drawable, run_mode, (GimpRgnFunc2) noisify_func, gr);
    }

  g_rand_free (gr);

}

static void
noisify_add_channel (GtkWidget *table, gint channel, gchar *name, 
		     GimpDrawable *drawable)
{
  GtkObject *adj;

  adj = gimp_scale_entry_new (GTK_TABLE (table), 0, channel + 1,
			      name, SCALE_WIDTH, 0,
			      nvals.noise[channel], 0.0, 1.0, 0.01, 0.1, 2,
			      TRUE, 0, 0,
			      NULL, NULL);

  g_object_set_data (G_OBJECT (adj), "drawable", drawable);

  g_signal_connect (adj, "value_changed",
		    G_CALLBACK (noisify_double_adjustment_update),
		    &nvals.noise[channel]);

  noise_int.channel_adj[channel] = adj;
}

static gint
noisify_dialog (GimpDrawable *drawable, 
		gint       channels)
{
  GtkWidget *dlg;
  GtkWidget *main_vbox;
  GtkWidget *toggle;
  GtkWidget *frame;
  GtkWidget *table;

  gimp_ui_init ("noisify", FALSE);

  dlg = gimp_dialog_new (_("Noisify"), "noisify",
			 gimp_standard_help_func, "filters/noisify.html",
			 GTK_WIN_POS_MOUSE,
			 FALSE, TRUE, FALSE,

			 GTK_STOCK_CANCEL, gtk_widget_destroy,
			 NULL, 1, NULL, FALSE, TRUE,
			 GTK_STOCK_OK, noisify_ok_callback,
			 NULL, NULL, NULL, TRUE, FALSE,

			 NULL);

  g_signal_connect (dlg, "destroy",
                    G_CALLBACK (gtk_main_quit),
                    NULL);

  main_vbox = gtk_vbox_new (FALSE, 2);
  gtk_container_set_border_width (GTK_CONTAINER (main_vbox), 0);
  gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dlg)->vbox), main_vbox, TRUE, TRUE, 0);
  gtk_widget_show (main_vbox);

  /* preview */
  preview = gimp_fixme_preview_new (NULL, TRUE);
  gtk_box_pack_start (GTK_BOX (main_vbox), preview->frame, FALSE, FALSE, 0);
  gtk_widget_show (preview->widget);
  gimp_fixme_preview_fill (preview, drawable);
  noisify (drawable, TRUE); /* preview noisify */
  
  /*  parameter settings  */
  frame = gtk_frame_new (_("Parameter Settings"));
  gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_ETCHED_IN);
  gtk_container_set_border_width (GTK_CONTAINER (frame), 6);
  gtk_box_pack_start (GTK_BOX (main_vbox), frame, TRUE, TRUE, 0);

  table = gtk_table_new (channels + 1, 3, FALSE);
  gtk_table_set_col_spacings (GTK_TABLE (table), 4);
  gtk_table_set_row_spacings (GTK_TABLE (table), 2);
  gtk_table_set_row_spacing (GTK_TABLE (table), 0, 4);
  gtk_container_set_border_width (GTK_CONTAINER (table), 4);
  gtk_container_add (GTK_CONTAINER (frame), table);

  toggle = gtk_check_button_new_with_mnemonic (_("_Independent"));
  gtk_table_attach (GTK_TABLE (table), toggle, 0, 3, 0, 1, GTK_FILL, 0, 0, 0);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle), nvals.independent);
  gtk_widget_show (toggle);

  g_signal_connect (toggle, "toggled",
                    G_CALLBACK (gimp_toggle_button_update),
                    &nvals.independent);

  noise_int.channels = channels;

  if (channels == 1) 
    {
      noisify_add_channel (table, 0, _("_Gray:"), drawable);
    }
  else if (channels == 2)
    {
      noisify_add_channel (table, 0, _("_Gray:"), drawable);
      noisify_add_channel (table, 1, _("_Alpha:"), drawable);
    }  
  else if (channels == 3)
    {
      noisify_add_channel (table, 0, _("_Red:"), drawable);
      noisify_add_channel (table, 1, _("_Green:"), drawable);
      noisify_add_channel (table, 2, _("_Blue:"), drawable);
    }

  else if (channels == 4)
    {
      noisify_add_channel (table, 0, _("_Red:"), drawable);
      noisify_add_channel (table, 1, _("_Green:"), drawable);
      noisify_add_channel (table, 2, _("_Blue:"), drawable);
      noisify_add_channel (table, 3, _("_Alpha:"), drawable);
    }
  else
    {
      gchar *buffer;
      gint   i;

      for (i = 0; i < channels; i++)
	{
	  buffer = g_strdup_printf (_("Channel #%d:"), i);

	  noisify_add_channel (table, i, buffer, drawable);

	  g_free (buffer);
	}
    }

  gtk_widget_show (frame);
  gtk_widget_show (table);

  gtk_widget_show (dlg);

  gtk_main ();
  gdk_flush ();

  return noise_int.run;
}

/*
 * Return a Gaussian (aka normal) random variable.
 *
 * Adapted from ppmforge.c, which is part of PBMPLUS.
 * The algorithm comes from:
 * 'The Science Of Fractal Images'. Peitgen, H.-O., and Saupe, D. eds.
 * Springer Verlag, New York, 1988.
 *
 * It would probably be better to use another algorithm, such as that 
 * in Knuth
 */
static gdouble
gauss (GRand *gr)
{
  gint i;
  gdouble sum = 0.0;

  for (i = 0; i < 4; i++)
    sum += g_rand_int_range (gr, 0, 0x7FFF);

  return sum * 5.28596089837e-5 - 3.46410161514;
}

static void
noisify_ok_callback (GtkWidget *widget,
		     gpointer   data)
{
  noise_int.run = TRUE;

  gtk_widget_destroy (GTK_WIDGET (data));
}

static void
noisify_double_adjustment_update (GtkAdjustment *adjustment,
				  gpointer       data)
{
  GimpDrawable *drawable;
  
  gimp_double_adjustment_update (adjustment, data);

  drawable = g_object_get_data (G_OBJECT (adjustment), "drawable");

  noisify (drawable, TRUE);

  if (! nvals.independent)
    {
      gint i;

      for (i = 0; i < noise_int.channels; i++)
	if (adjustment != GTK_ADJUSTMENT (noise_int.channel_adj[i]))
	  gtk_adjustment_set_value (GTK_ADJUSTMENT (noise_int.channel_adj[i]),
				    adjustment->value);
    }
}