/* max_rgb.c -- This is a plug-in for the GIMP (1.0's API)
 * Author: Shuji Narazaki <narazaki@InetQ.or.jp>
 * Time-stamp: <2000-01-01 00:24:57 yasuhiro>
 * Version: 0.35
 *
 * Copyright (C) 1997 Shuji Narazaki <narazaki@InetQ.or.jp>
 *
 * 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 <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <gtk/gtk.h>

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

#include "libgimp/stdplugins-intl.h"

/* Replace them with the right ones */
#define	PLUG_IN_NAME	     "plug_in_max_rgb"
#define SHORT_NAME	     "max_rgb"
#define PROGRESS_UPDATE_NUM  100

static void	query	(void);
static void	run	(gchar  *name,
			 gint    nparams,
			 GParam *param,
			 gint   *nreturn_vals,
			 GParam **return_vals);

static GStatusType main_function (gint32 drawable_id);

static gint	   dialog      (void);
static void        ok_callback (GtkWidget *widget,
				gpointer   data);


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

enum
{
  MIN_CHANNELS = 0,
  MAX_CHANNELS = 1
};

typedef struct
{
  gint max_p;  /* gint, gdouble, and so on */
} ValueType;

typedef struct 
{
  gint run;
} Interface;

static ValueType pvals = 
{
  MAX_CHANNELS
};

static Interface interface =
{
  FALSE
};


MAIN ()

static void
query (void)
{
  static GParamDef args [] =
  {
    { PARAM_INT32, "run_mode", "Interactive, non-interactive"},
    { PARAM_IMAGE, "image", "Input image (not used)"},
    { PARAM_DRAWABLE, "drawable", "Input drawable"},
    { PARAM_INT32, "max_p", "1 for maximizing, 0 for minimizing"}
  };
  static GParamDef *return_vals = NULL;
  static int nargs = sizeof (args) / sizeof (args[0]);
  static int nreturn_vals = 0;

  INIT_I18N();
  
  gimp_install_procedure (PLUG_IN_NAME,
			  _("Return an image in which each pixel holds only the channel that has the maximum value in three (red, green, blue) channels, and other channels are zero-cleared"),
			  "the help is not yet written for this plug-in",
			  "Shuji Narazaki (narazaki@InetQ.or.jp)",
			  "Shuji Narazaki",
			  "1997",
                          N_("<Image>/Filters/Colors/Max RGB..."),
			  "RGB*",
			  PROC_PLUG_IN,
			  nargs, nreturn_vals,
			  args, return_vals);
}

static void
run (char	*name,
     int	nparams,
     GParam	*param,
     int	*nreturn_vals,
     GParam	**return_vals)
{
  static GParam	 values[1];
  GStatusType	status = STATUS_EXECUTION_ERROR;
  GRunModeType	run_mode;
  gint		drawable_id;
  
  run_mode = param[0].data.d_int32;
  drawable_id = param[2].data.d_int32;

  *nreturn_vals = 1;
  *return_vals = values;
  
  values[0].type = PARAM_STATUS;
  values[0].data.d_status = status;

  switch (run_mode)
    {
    case RUN_INTERACTIVE:
      INIT_I18N_UI();
      gimp_get_data (PLUG_IN_NAME, &pvals);
      /* Since a channel might be selected, we must check wheter RGB or not. */
      if (!gimp_drawable_is_rgb(drawable_id))
	{
	  gimp_message (_("RGB drawable is not selected."));
	  return;
	}
      if (! dialog ())
	return;
      break;
    case RUN_NONINTERACTIVE:
      INIT_I18N();
      /* You must copy the values of parameters to pvals or dialog variables. */
      break;
    case RUN_WITH_LAST_VALS:
      INIT_I18N();
      gimp_get_data (PLUG_IN_NAME, &pvals);
      break;
    }
  
  status = main_function (drawable_id);

  if (run_mode != RUN_NONINTERACTIVE)
    gimp_displays_flush();
  if (run_mode == RUN_INTERACTIVE && status == STATUS_SUCCESS )
    gimp_set_data (PLUG_IN_NAME, &pvals, sizeof (ValueType));

  values[0].type = PARAM_STATUS;
  values[0].data.d_status = status;
}

static GStatusType
main_function (gint32 drawable_id)
{
  GDrawable *drawable;
  GPixelRgn  src_rgn, dest_rgn;
  guchar    *src, *dest;
  gpointer   pr;
  gint       x, y, x1, x2, y1, y2;
  gint       gap, total, processed = 0;
  gint       init_value, flag;

  init_value = (pvals.max_p > 0) ? 0 : 255;
  flag = (0 < pvals.max_p) ? 1 : -1;

  drawable = gimp_drawable_get (drawable_id);
  gap = (gimp_drawable_has_alpha (drawable_id)) ? 1 : 0;
  gimp_drawable_mask_bounds (drawable_id, &x1, &y1, &x2, &y2);
  total = (x2 - x1) * (y2 - y1);

  gimp_tile_cache_ntiles (2 * (drawable->width / gimp_tile_width () + 1));
  gimp_pixel_rgn_init (&src_rgn, drawable, x1, y1, (x2 - x1), (y2 - y1), FALSE, FALSE);
  gimp_pixel_rgn_init (&dest_rgn, drawable, x1, y1, (x2 - x1), (y2 - y1), TRUE, TRUE);

  pr = gimp_pixel_rgns_register (2, &src_rgn, &dest_rgn);
  gimp_progress_init ( _("max_rgb: scanning..."));
  for (; pr != NULL; pr = gimp_pixel_rgns_process (pr))
    {
      for (y = 0; y < src_rgn.h; y++)
	{
	  src = src_rgn.data + y * src_rgn.rowstride;
	  dest = dest_rgn.data + y * dest_rgn.rowstride;

	  for (x = 0; x < src_rgn.w; x++)
	    {
	      gint	ch, max_ch = 0;
	      guchar	max, tmp_value;
	      
	      max = init_value;
	      for (ch = 0; ch < 3; ch++)
		if (flag * max <= flag * (tmp_value = (*src++)))
		  {
		  if (max == tmp_value)
		    max_ch += 1 << ch;
		  else
		    {
		      max_ch = 1 << ch; /* clear memories of old channels */
		      max = tmp_value;
		    }
		  }
	      for ( ch = 0; ch < 3; ch++)
		*dest++ = (guchar)(((max_ch & (1 << ch)) > 0) ? max : 0);
	      if (gap) *dest++=*src++;
	      if ((++processed % (total / PROGRESS_UPDATE_NUM)) == 0)
		gimp_progress_update ((double)processed /(double) total); 
	    }
	}
  }
  gimp_progress_update (1.0);
  gimp_drawable_flush (drawable);
  gimp_drawable_merge_shadow (drawable->id, TRUE);
  gimp_drawable_update (drawable->id, x1, y1, (x2 - x1), (y2 - y1));
  gimp_drawable_detach (drawable);
  return STATUS_SUCCESS;
}

/* dialog stuff */
static gint
dialog (void)
{
  GtkWidget *dlg;
  GtkWidget *frame;
  gchar	**argv;
  gint	  argc;

  argc    = 1;
  argv    = g_new (gchar *, 1);
  argv[0] = g_strdup (PLUG_IN_NAME);

  gtk_init (&argc, &argv);
  gtk_rc_parse (gimp_gtkrc ());

  dlg = gimp_dialog_new (_("Max RGB"), "max_rgb",
			 gimp_plugin_help_func, "filters/max_rgb.html",
			 GTK_WIN_POS_MOUSE,
			 FALSE, TRUE, FALSE,

			 _("OK"), ok_callback,
			 NULL, NULL, NULL, TRUE, FALSE,
			 _("Cancel"), gtk_widget_destroy,
			 NULL, 1, NULL, FALSE, TRUE,

			 NULL);

  gtk_signal_connect (GTK_OBJECT (dlg), "destroy",
		      GTK_SIGNAL_FUNC (gtk_main_quit),
		      NULL);

  frame = gimp_radio_group_new2 (TRUE, _("Parameter Settings"),
				 gimp_radio_button_update,
				 &pvals.max_p, (gpointer) pvals.max_p,

				 _("Hold the Maximal Channels"),
				 (gpointer) MAX_CHANNELS, NULL,
				 _("Hold the Minimal Channels"),
				 (gpointer) MIN_CHANNELS, NULL,

				 NULL);
  gtk_container_set_border_width (GTK_CONTAINER (frame), 6);
  gtk_container_add (GTK_CONTAINER (GTK_DIALOG (dlg)->vbox), frame);
  gtk_widget_show (frame);

  gtk_widget_show (dlg);

  gtk_main ();
  gdk_flush ();

  return interface.run;
}

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

  gtk_widget_destroy (GTK_WIDGET (data));
}