/* Deinterlace 1.00 - image processing plug-in for the Gimp 1.0 API
 *
 * Copyright (C) 1997 Andrew Kieschnick (andrewk@mail.utexas.edu)
 *
 * Original deinterlace for the Gimp 0.54 API by Federico Mena Quintero
 *
 * Copyright (C) 1996 Federico Mena Quintero
 *
 * Any bugs in this code are probably my (Andrew Kieschnick's) fault, as I
 * pretty much rewrote it from scratch.
 *
 * 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 <gtk/gtk.h>

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

#include "libgimp/stdplugins-intl.h"


enum
{
  ODD_FIELDS,
  EVEN_FIELDS
};

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

static void      deinterlace        (GimpDrawable  *drawable);

static gboolean  deinterlace_dialog (void);


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

static gint DeinterlaceValue = EVEN_FIELDS;

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,     "evenodd",  "0 = keep odd, 1 = keep even"  }
  };

  gimp_install_procedure ("plug_in_deinterlace",
			  "Deinterlace",
			  "Deinterlace is useful for processing images from "
			  "video capture cards. When only the odd or even "
			  "fields get captured, deinterlace can be used to "
			  "interpolate between the existing fields to correct "
			  "this.",
			  "Andrew Kieschnick",
			  "Andrew Kieschnick",
			  "1997",
			  N_("_Deinterlace..."),
			  "RGB*, GRAY*",
			  GIMP_PLUGIN,
			  G_N_ELEMENTS (args), 0,
			  args, NULL);

  gimp_plugin_menu_register ("plug_in_deinterlace",
                             N_("<Image>/Filters/Enhance"));
}

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

  run_mode = param[0].data.d_int32;

  INIT_I18N ();

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

  switch (run_mode)
    {
    case GIMP_RUN_INTERACTIVE:
      gimp_get_data ("plug_in_deinterlace", &DeinterlaceValue);
      if (! deinterlace_dialog ())
	status = GIMP_PDB_EXECUTION_ERROR;
      break;

    case GIMP_RUN_NONINTERACTIVE:
      if (nparams != 4)
	status = GIMP_PDB_CALLING_ERROR;
      if (status == GIMP_PDB_SUCCESS)
	DeinterlaceValue = param[3].data.d_int32;
      break;

    case GIMP_RUN_WITH_LAST_VALS:
      gimp_get_data ("plug_in_deinterlace", &DeinterlaceValue);
      break;

    default:
      break;
    }

  if (status == GIMP_PDB_SUCCESS)
    {
      /*  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 (_("Deinterlace..."));
	  gimp_tile_cache_ntiles (2 * (drawable->width /
				       gimp_tile_width () + 1));
	  deinterlace (drawable);

	  if (run_mode != GIMP_RUN_NONINTERACTIVE)
	    gimp_displays_flush ();
	  if (run_mode == GIMP_RUN_INTERACTIVE)
	    gimp_set_data ("plug_in_deinterlace",
			   &DeinterlaceValue, sizeof (DeinterlaceValue));
	}
      else
	{
	  /* gimp_message ("deinterlace: cannot operate on indexed color images"); */
	  status = GIMP_PDB_EXECUTION_ERROR;
	}
    }
  *nreturn_vals = 1;
  *return_vals = values;

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

  gimp_drawable_detach (drawable);
}

static void
deinterlace (GimpDrawable *drawable)
{
  GimpPixelRgn srcPR, destPR;
  gint width, height;
  gint bytes;
  gint has_alpha;
  guchar *dest;
  guchar *upper;
  guchar *lower;
  gint row, col;
  gint x1, y1, x2, y2;

  /* Get the input area. This is the bounding box of the selection in
   *  the image (or the entire image if there is no selection). Only
   *  operating on the input area is simply an optimization. It doesn't
   *  need to be done for correct operation. (It simply makes it go
   *  faster, since fewer pixels need to be operated on).
   */

  gimp_drawable_mask_bounds (drawable->drawable_id, &x1, &y1, &x2, &y2);

  has_alpha = gimp_drawable_has_alpha (drawable->drawable_id);
  /* Get the size of the input image. (This will/must be the same
   *  as the size of the output image.
   */
  width  = drawable->width;
  height = drawable->height;
  bytes  = drawable->bpp;

  /*  allocate row buffers  */
  dest  = g_new (guchar, (x2 - x1) * bytes);
  upper = g_new (guchar, (x2 - x1) * bytes);
  lower = g_new (guchar, (x2 - x1) * bytes);

  /*  initialize the pixel regions  */
  gimp_pixel_rgn_init (&srcPR, drawable, 0, 0, width, height, FALSE, FALSE);
  gimp_pixel_rgn_init (&destPR, drawable, 0, 0, width, height, TRUE, TRUE);

  /*  loop through the rows, performing our magic*/
  for (row = y1; row < y2; row++)
    {
      gimp_pixel_rgn_get_row (&srcPR, dest, x1, row, (x2-x1));

      /* Only do interpolation if the row:
	 (1) Isn't one we want to keep
	 (2) Has both an upper and a lower row
	 Otherwise, just duplicate the source row
      */
      if (!((row % 2 == DeinterlaceValue) ||
	    (row - 1 < 0) ||
	    (row + 1 >= height)))
	{
	  gimp_pixel_rgn_get_row (&srcPR, upper, x1, row-1, (x2-x1));
	  gimp_pixel_rgn_get_row (&srcPR, lower, x1, row+1, (x2-x1));

          if (has_alpha)
            {
              guchar *upix = upper;
              guchar *lpix = lower;
              guchar *dpix = dest;

	      for (col = 0; col < x2-x1; col++)
                {
                  gint  b;
                  guint ualpha = upix[bytes-1];
                  guint lalpha = lpix[bytes-1];
                  guint alpha  = ualpha + lalpha;

                  if ((dpix[bytes-1] = (alpha >> 1)))
                    {
                      for (b = 0; b < bytes-1; b++)
			dpix[b] = (upix[b] * ualpha + lpix[b] * lalpha) / alpha;
                    }

                  upix += bytes;
                  lpix += bytes;
                  dpix += bytes;
                }
            }
          else
            {
              for (col = 0; col < ((x2-x1)*bytes); col++)
                   dest[col] = (upper[col] + lower[col]) >> 1;
            }
	}
      gimp_pixel_rgn_set_row (&destPR, dest, x1, row, (x2-x1));

      if ((row % 5) == 0)
	gimp_progress_update ((double) row / (double) (y2 - y1));
    }

  /*  update the deinterlaced region  */
  gimp_drawable_flush (drawable);
  gimp_drawable_merge_shadow (drawable->drawable_id, TRUE);
  gimp_drawable_update (drawable->drawable_id, x1, y1, (x2 - x1), (y2 - y1));

  g_free (lower);
  g_free (upper);
  g_free (dest);
}

static gboolean
deinterlace_dialog (void)
{
  GtkWidget *dlg;
  GtkWidget *frame;
  gboolean   run;

  gimp_ui_init ("deinterlace", FALSE);

  dlg = gimp_dialog_new (_("Deinterlace"), "deinterlace",
                         NULL, 0,
			 gimp_standard_help_func, "plug-in-deinterlace",

			 GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
			 GTK_STOCK_OK,     GTK_RESPONSE_OK,

			 NULL);

  frame = gimp_int_radio_group_new (FALSE, NULL,
                                    G_CALLBACK (gimp_radio_button_update),
                                    &DeinterlaceValue, DeinterlaceValue,

                                    _("Keep O_dd Fields"),  ODD_FIELDS,  NULL,
                                    _("Keep _Even Fields"), EVEN_FIELDS, NULL,

                                    NULL);

  gtk_container_set_border_width (GTK_CONTAINER (frame), 12);
  gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dlg)->vbox), frame, TRUE, TRUE, 0);
  gtk_widget_show (frame);

  gtk_widget_show (dlg);

  run = (gimp_dialog_run (GIMP_DIALOG (dlg)) == GTK_RESPONSE_OK);

  gtk_widget_destroy (dlg);

  return run;
}
