/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 *  Rotate plug-in v1.0
 *  Copyright 1997-2000 by Sven Neumann <sven@gimp.org>
 *                       & Adam D. Moss <adam@gimp.org>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

/* Revision history
 *  (09/28/97)  v0.1   first development release
 *  (09/29/97)  v0.2   nicer dialog,
 *                     changed the menu-location to Filters/Transforms
 *  (10/01/97)  v0.3   now handles layered images and undo
 *  (10/13/97)  v0.3a  small bugfix, no real changes
 *  (10/17/97)  v0.4   now handles selections
 *  (01/09/98)  v0.5   a few fixes to support portability
 *  (01/15/98)  v0.6   fixed a line that caused rotate to crash on some
 *                     systems
 *  (05/28/98)  v0.7   use the new gimp_message function for error output
 *  (10/09/99)  v0.8   rotate guides too
 *  (11/13/99)  v0.9   merge rotators and rotate plug-ins
 *                     -> drop the dialog, register directly into menus instead
 *  (06/18/00)  v1.0   speed up 180° rotations,
 *                     declare version 1.0 for gimp-1.2 release
 */

/* TODO List
 *  - handle channels and masks
 *  - rewrite the main function to make it work on tiles rather than
 *    process the image row by row. This should result in a significant
 *    speedup (thanks to quartic for this suggestion).
 *  - do something magical so that only one rotate can be occuring at a time!
 */

#include "config.h"

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

#include <libgimp/gimp.h>

#include "libgimp/stdplugins-intl.h"


/* Defines */
#define PLUG_IN_PROC        "plug-in-rotate"
#define PLUG_IN_VERSION     "v1.0 (2000/06/18)"
#define PLUG_IN_IMAGE_TYPES "RGB*, INDEXED*, GRAY*"
#define PLUG_IN_AUTHOR      "Sven Neumann <sven@gimp.org>, Adam D. Moss <adam@gimp.org>"
#define PLUG_IN_COPYRIGHT   "Sven Neumann, Adam D. Moss"


typedef struct
{
  gint angle;
  gint everything;
} RotateValues;

typedef struct
{
  gint32 ID;
  gint32 orientation;
  gint32 position;
} GuideInfo;

static RotateValues rotvals =
{
  1,        /* default to 90 degrees */
  1         /* default to whole image */
};


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

static void  rotate                 (void);
static void  rotate_drawable        (GimpDrawable *drawable);
static void  rotate_compute_offsets (gint         *offsetx,
                                     gint         *offsety,
                                     gint          image_width,
                                     gint          image_height,
                                     gint          width,
                                     gint          height);

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

/* the image and drawable that will be used later */
static GimpDrawable *active_drawable = NULL;
static gint32        image_ID        = -1;

/* Functions */

MAIN ()

static void
query (void)
{
  static const GimpParamDef args[] =
  {
    { GIMP_PDB_INT32,    "run-mode",   "The run mode { RUN-INTERACTIVE (0), RUN-NONINTERACTIVE (1) }" },
    { GIMP_PDB_IMAGE,    "image",      "Input image"                  },
    { GIMP_PDB_DRAWABLE, "drawable",   "Input drawable"               },
    { GIMP_PDB_INT32,    "angle",      "Angle { 90 (1), 180 (2), 270 (3) } degrees" },
    { GIMP_PDB_INT32,    "everything", "Rotate the whole image { TRUE, FALSE }" }
  };

  gimp_install_procedure (PLUG_IN_PROC,
                          "Rotates a layer or the whole image by 90, 180 or 270 degrees",
                          "This plug-in does rotate the active layer or the "
                          "whole image clockwise by multiples of 90 degrees. "
                          "When the whole image is choosen, the image is "
                          "resized if necessary.",
                          PLUG_IN_AUTHOR,
                          PLUG_IN_COPYRIGHT,
                          PLUG_IN_VERSION,
                          NULL,
                          PLUG_IN_IMAGE_TYPES,
                          GIMP_PLUGIN,
                          G_N_ELEMENTS (args), 0,
                          args, NULL);
}

static void
run (const gchar      *name,
     gint              nparams,
     const GimpParam  *param,
     gint             *nreturn_vals,
     GimpParam       **return_vals)
{
  GimpRunMode       run_mode = param[0].data.d_int32;
  GimpPDBStatusType status   = GIMP_PDB_SUCCESS;
  static GimpParam  values[1];

  *nreturn_vals = 1;
  *return_vals  = values;

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

  INIT_I18N ();

  image_ID        = param[1].data.d_int32;
  active_drawable = gimp_drawable_get (param[2].data.d_drawable);

  if (strcmp (name, PLUG_IN_PROC) == 0)
    {
      switch (run_mode)
        {
        case GIMP_RUN_INTERACTIVE:
        case GIMP_RUN_NONINTERACTIVE:
          /* check to see if invoked with the correct number of parameters */
          if (nparams == 5)
            {
              rotvals.angle = (gint) param[3].data.d_int32;
              rotvals.angle = rotvals.angle % 4;
              rotvals.everything = (gint) param[4].data.d_int32;
              /* Store variable states for next run */
              gimp_set_data (PLUG_IN_PROC, &rotvals, sizeof (RotateValues));
            }
          else
            status = GIMP_PDB_CALLING_ERROR;
          break;
        case GIMP_RUN_WITH_LAST_VALS:
          /* Possibly retrieve data from a previous run */
          gimp_get_data (PLUG_IN_PROC, &rotvals);
          rotvals.angle = rotvals.angle % 4;
          break;
        default:
          break;
        }
    }
  else
    {
      status = GIMP_PDB_CALLING_ERROR;
    }

  if (status == GIMP_PDB_SUCCESS)
    {
      /* Run the main function */
      rotate ();

      /* If run mode is interactive, flush displays, else (script) don't
         do it, as the screen updates would make the scripts slow */
      if (run_mode != GIMP_RUN_NONINTERACTIVE)
        gimp_displays_flush ();
    }

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

static void
rotate_compute_offsets (gint *offsetx,
                        gint *offsety,
                        gint  image_width,
                        gint  image_height,
                        gint  width,
                        gint  height)
{
  gint buffer;

  if (rotvals.everything)  /* rotate around the image center */
    {
      switch (rotvals.angle)
        {
        case 1:   /* 90° */
          buffer   = *offsetx;
          *offsetx = image_height - *offsety - height;
          *offsety = buffer;
          break;
        case 2:   /* 180° */
          *offsetx = image_width - *offsetx - width;
          *offsety = image_height - *offsety - height;
          break;
        case 3:   /* 270° */
          buffer   = *offsetx;
          *offsetx = *offsety;
          *offsety = image_width - buffer - width;
        }
    }
  else  /* rotate around the drawable center */
    {
      if (rotvals.angle != 2)
        {
          *offsetx = *offsetx + (width-height)/2 ;
          *offsety = *offsety + (height-width)/2 ;
        }
    }
  return;
}


static void
rotate_drawable (GimpDrawable *drawable)
{
  GimpPixelRgn  srcPR, destPR;
  gint          width, height;
  gint          longside;
  gint          bytes;
  gint          row, col;
  gint          offsetx, offsety;
  gboolean      was_lock_alpha = FALSE;
  guchar       *buffer;
  guchar       *src_row, *dest_row;

  /* initialize */

  row = 0;

  /* Get the size of the input drawable. */
  width = drawable->width;
  height = drawable->height;
  bytes = drawable->bpp;

  if (gimp_layer_get_lock_alpha (drawable->drawable_id))
    {
      was_lock_alpha = TRUE;
      gimp_layer_set_lock_alpha (drawable->drawable_id, FALSE);
    }

  if (rotvals.angle == 2)  /* we're rotating by 180° */
    {
      gimp_tile_cache_ntiles (2 * (width / gimp_tile_width() + 1));

      gimp_pixel_rgn_init (&srcPR, drawable, 0, 0, width, height,
                           FALSE, FALSE);
      gimp_pixel_rgn_init (&destPR, drawable, 0, 0, width, height,
                           TRUE, TRUE);

      src_row  = (guchar *) g_malloc (width * bytes);
      dest_row = (guchar *) g_malloc (width * bytes);

      for (row = 0; row < height; row++)
        {
          gimp_pixel_rgn_get_row (&srcPR, src_row, 0, row, width);
          for (col = 0; col < width; col++)
            {
              memcpy (dest_row + col * bytes,
                      src_row + (width - 1 - col) * bytes,
                      bytes);
            }
          gimp_pixel_rgn_set_row (&destPR, dest_row, 0, (height - row - 1),
                                  width);

          if ((row % 5) == 0)
            gimp_progress_update ((double) row / (double) height);
        }

      g_free (src_row);
      g_free (dest_row);

      gimp_drawable_flush (drawable);
      gimp_drawable_merge_shadow (drawable->drawable_id, TRUE);
      gimp_drawable_update (drawable->drawable_id, 0, 0, width, height);

    }
  else                     /* we're rotating by 90° or 270° */
    {
      (width > height) ? (longside = width) : (longside = height);

      gimp_layer_resize (drawable->drawable_id, longside, longside, 0, 0);
      drawable = gimp_drawable_get (drawable->drawable_id);
      gimp_drawable_flush (drawable);

      gimp_tile_cache_ntiles ((longside / gimp_tile_width () + 1) +
                              (longside / gimp_tile_height () + 1));

      gimp_pixel_rgn_init (&srcPR, drawable, 0, 0, longside, longside,
                           FALSE, FALSE);
      gimp_pixel_rgn_init (&destPR, drawable, 0, 0, longside, longside,
                           TRUE, TRUE);

      buffer = g_malloc (longside * bytes);

      if (rotvals.angle == 1)     /* we're rotating by 90° */
        {
          for (row = 0; row < height; row++)
            {
              gimp_pixel_rgn_get_row (&srcPR, buffer, 0, row, width);
              gimp_pixel_rgn_set_col (&destPR, buffer, (height - row - 1), 0,
                                      width);

              if ((row % 5) == 0)
                gimp_progress_update ((double) row / (double) height);
            }
        }
      else                        /* we're rotating by 270° */
        {
          for (col = 0; col < width; col++)
            {
              gimp_pixel_rgn_get_col (&srcPR, buffer, col, 0, height);
              gimp_pixel_rgn_set_row (&destPR, buffer, 0, (width - col - 1),
                                      height);

              if ((col % 5) == 0)
                gimp_progress_update ((double) col / (double) width);
            }
        }

      g_free (buffer);

      gimp_progress_update (1.0);

      gimp_drawable_flush (drawable);
      gimp_drawable_merge_shadow (drawable->drawable_id, TRUE);
      gimp_drawable_update (drawable->drawable_id, 0, 0, height, width);

      gimp_layer_resize (drawable->drawable_id, height, width, 0, 0);
      drawable = gimp_drawable_get (drawable->drawable_id);
      gimp_drawable_flush (drawable);
      gimp_drawable_update (drawable->drawable_id, 0, 0, height, width);
    }

  gimp_drawable_offsets (drawable->drawable_id, &offsetx, &offsety);
  rotate_compute_offsets (&offsetx, &offsety,
                          gimp_image_width (image_ID),
                          gimp_image_height (image_ID),
                          width, height);
  gimp_layer_set_offsets (drawable->drawable_id, offsetx, offsety);

  if (was_lock_alpha)
    gimp_layer_set_lock_alpha (drawable->drawable_id, TRUE);

  return;
}


/* The main rotate function */
static void
rotate (void)
{
  GimpDrawable *drawable;
  gint32       *layers;
  gint          i;
  gint          nlayers;
  gint32        guide_ID;
  GuideInfo    *guide;
  GList        *guides = NULL;
  GList        *list;

  if (rotvals.angle == 0) return;

  /* if there's a selection and we try to rotate the whole image */
  /* create an error message and exit                            */
  if (rotvals.everything)
    {
      if (! gimp_selection_is_empty (image_ID))
        {
          gimp_message (_("You can not rotate the whole image if there's a selection."));
          gimp_drawable_detach (active_drawable);
          return;
        }
      if (gimp_item_is_layer (active_drawable->drawable_id) &&
          gimp_layer_is_floating_sel (active_drawable->drawable_id))
        {
          gimp_message (_("You can not rotate the whole image if there's a floating selection."));
          gimp_drawable_detach (active_drawable);
          return;
        }
    }
  else
    /* if we are trying to rotate a channel or a mask,
       create an error message and exit */
    {
      if (! gimp_item_is_layer (active_drawable->drawable_id))
        {
          gimp_message (_("Sorry, channels and masks can not be rotated."));
          gimp_drawable_detach (active_drawable);
          return;
        }
    }

  gimp_progress_init (_("Rotating"));

  gimp_image_undo_group_start (image_ID);

  if (rotvals.everything)  /* rotate the whole image */
    {
      gint32 width = gimp_image_width (image_ID);
      gint32 height = gimp_image_height (image_ID);

      gimp_drawable_detach (active_drawable);
      layers = gimp_image_get_layers (image_ID, &nlayers);
      for (i = 0; i < nlayers; i++)
        {
          drawable = gimp_drawable_get (layers[i]);
          rotate_drawable (drawable);
          gimp_drawable_detach (drawable);
        }
      g_free (layers);

      /* build a list of all guides and remove them */
      guide_ID = 0;
      while ((guide_ID = gimp_image_find_next_guide (image_ID, guide_ID)) != 0)
        {
          guide = g_new (GuideInfo, 1);
          guide->ID = guide_ID;
          guide->orientation = gimp_image_get_guide_orientation (image_ID,
                                                                 guide_ID);
          guide->position = gimp_image_get_guide_position (image_ID, guide_ID);
          guides = g_list_prepend (guides, guide);
        }
      for (list = guides; list; list = list->next)
        {
          guide = (GuideInfo *) list->data;
          gimp_image_delete_guide (image_ID, guide->ID);
        }

      /* if rotation is not 180 degrees, resize the image */
      /*    Do it now after the guides are removed, since */
      /*    gimp_image_resize() moves the guides.         */
      if (rotvals.angle != 2)
        gimp_image_resize (image_ID, height, width, 0, 0);

      /* add the guides back to the image */
      if (guides)
        {
          switch (rotvals.angle)
            {
            case 1:
              for (list = guides; list; list = list->next)
                {
                  guide = (GuideInfo *)list->data;
                  if (guide->orientation == GIMP_ORIENTATION_HORIZONTAL)
                    gimp_image_add_vguide (image_ID, height - guide->position);
                  else
                    gimp_image_add_hguide (image_ID, guide->position);
                  g_free (guide);
                }
              break;
            case 2:
              for (list = guides; list; list = list->next)
                {
                  guide = (GuideInfo *)list->data;
                  if (guide->orientation == GIMP_ORIENTATION_HORIZONTAL)
                    gimp_image_add_hguide (image_ID, height - guide->position);
                  else
                    gimp_image_add_vguide (image_ID, width - guide->position);
                  g_free (guide);
                }
              break;
            case 3:
              for (list = guides; list; list = list->next)
                {
                  guide = (GuideInfo *)list->data;
                  if (guide->orientation == GIMP_ORIENTATION_HORIZONTAL)
                    gimp_image_add_vguide (image_ID, guide->position);
                  else
                    gimp_image_add_hguide (image_ID, width - guide->position);
                  g_free (guide);
                }
              break;
            default:
              break;
            }
          g_list_free (guides);
        }
    }
  else  /* rotate only the active layer */
    {

      /* check for active selection and float it */
      if (! gimp_selection_is_empty (image_ID) &&
          ! gimp_layer_is_floating_sel (active_drawable->drawable_id))
        {
          active_drawable =
            gimp_drawable_get (gimp_selection_float (image_ID,
                                                     active_drawable->drawable_id,
                                                     0, 0));
        }

      rotate_drawable (active_drawable);
      gimp_drawable_detach (active_drawable);
    }

  gimp_image_undo_group_end (image_ID);

  return;
}
