/*******************************************************************************

  illusion.c  -- This is a plug-in for the GIMP 1.0

  Copyright (C) 1997  Hirotsuna Mizuno
                      s1041150@u-aizu.ac.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.,
  675 Mass Ave, Cambridge, MA 02139, USA.

*******************************************************************************/

#include <stdlib.h>
#include <gtk/gtk.h>
#include <math.h>
#include "libgimp/gimp.h"

#define PLUG_IN_NAME    "plug_in_illusion"
#define PLUG_IN_VERSION "v0.7 (Dec. 25 1997)"

#define DIALOG_CAPTION  "Illusion"

#ifndef PI
#define PI 3.141592653589793238462643383279
#endif
#ifndef PI_2
#define PI_2 (PI*2)
#endif

/******************************************************************************/

static void query( void );
static void run( char *, int, GParam *, int *, GParam ** );
static void filter( GDrawable *drawable );
static int  dialog( void );

/******************************************************************************/

typedef struct {
  gint32 division;
} parameter_t;

/******************************************************************************/

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

static parameter_t parameters = {
  8
};

static gint    image_width;
static gint    image_height;
static gint    image_bpp;
static gint    image_has_alpha;
static gint    select_x1;
static gint    select_y1;
static gint    select_x2;
static gint    select_y2;
static gint    select_width;
static gint    select_height;
static gdouble center_x;
static gdouble center_y;

/******************************************************************************/

MAIN()

/******************************************************************************/

static void query( void )
{
  static int nargs = 4;
  static GParamDef args[] = {
    { PARAM_INT32,    "run_mode",  "interactive / non-interactive" },
    { PARAM_IMAGE,    "image",     "input image" },
    { PARAM_DRAWABLE, "drawable",  "input drawable" },
    { PARAM_INT32,    "division",  "the number of divisions" }
  };
  static int nreturn_vals = 0;
  static GParamDef *return_vals = NULL;

  gimp_install_procedure(
			 PLUG_IN_NAME,
			 "produce illusion",
			 "produce illusion",
			 "Hirotsuna Mizuno <s1041150@u-aizu.ac.jp>",
			 "Hirotsuna Mizuno",
			 PLUG_IN_VERSION,
			 "<Image>/Filters/Map/Illusion",
			 "RGB*, GRAY*",
			 PROC_PLUG_IN,
			 nargs,
			 nreturn_vals,
			 args,
			 return_vals 
			 );
}

/******************************************************************************/

static void run( char    *name,
		 int      paramc,
		 GParam  *params,
		 int     *returnc,
		 GParam **returns )
{
  GDrawable     *drawable;
  GRunModeType   run_mode;
  static GParam  returnv[1];
  GStatusType    status = STATUS_SUCCESS;

  run_mode = params[0].data.d_int32;
  drawable = gimp_drawable_get( params[2].data.d_drawable );
  *returnc = 1;
  *returns = returnv;

  /* get the drawable info */
  image_width     = gimp_drawable_width( drawable->id );
  image_height    = gimp_drawable_height( drawable->id );
  image_bpp       = gimp_drawable_bpp( drawable->id );
  image_has_alpha = gimp_drawable_has_alpha( drawable->id );
  gimp_drawable_mask_bounds( drawable->id,
			     &select_x1, &select_y1, &select_x2, &select_y2 );
  select_width    = select_x2 - select_x1;
  select_height   = select_y2 - select_y1;
  center_x        = select_x1 + (gdouble)select_width / 2;
  center_y        = select_y1 + (gdouble)select_height / 2;

  /* switch the run mode */
  switch( run_mode ){

  case RUN_INTERACTIVE:
    gimp_get_data( PLUG_IN_NAME, &parameters );
    if( ! dialog() ) return;
    gimp_set_data( PLUG_IN_NAME, &parameters, sizeof( parameter_t ) );
    break;

  case RUN_NONINTERACTIVE:
    if( paramc != 4 ){
      status = STATUS_CALLING_ERROR;
    } else {
      parameters.division = params[3].data.d_int32;
    }
    break;

  case RUN_WITH_LAST_VALS:
    gimp_get_data( PLUG_IN_NAME, &parameters );
    break;
    
  }

  if( status == STATUS_SUCCESS ){

    if( gimp_drawable_color( drawable->id ) || 
	gimp_drawable_gray( drawable->id ) ){

      gimp_tile_cache_ntiles( 2 * ( drawable->width / gimp_tile_width() + 1 ) );
      filter( drawable );
      if( run_mode != RUN_NONINTERACTIVE ) gimp_displays_flush ();

    } else {

      status = STATUS_EXECUTION_ERROR;
      
    }
    
  }

  returnv[0].type          = PARAM_STATUS;
  returnv[0].data.d_status = status;

  gimp_drawable_detach( drawable );
}

/******************************************************************************/

static void filter( GDrawable *drawable )
{
  GPixelRgn srcPR, destPR;
  guchar  **pixels;
  guchar  **destpixels;
  gint      x, y, b;
  gint      xx, yy;
  gdouble   scale, radius, cx, cy, angle, offset;
  
  gimp_pixel_rgn_init( &srcPR, drawable,
		       0, 0, image_width, image_height, FALSE, FALSE );
  gimp_pixel_rgn_init( &destPR, drawable,
		       0, 0, image_width, image_height, TRUE, TRUE );

  pixels = (guchar **)malloc( image_height * sizeof(guchar *) );
  destpixels = (guchar **)malloc( image_height * sizeof(guchar *) );
  for( y = 0; y < image_height; y++ ){
    pixels[y] = (guchar *)malloc( image_width * image_bpp );
    destpixels[y] = (guchar *)malloc( image_width * image_bpp );
    gimp_pixel_rgn_get_row( &srcPR, pixels[y], 0, y, image_width );
  }

  /*
  for( y = select_y1; y < select_y2; y++ ){
    for( x = select_x1; x < select_x2; x++ ){
      for( b = 0; b < image_bpp; b++ ){
	destpixels[y][x*image_bpp+b] = 0;
      }
    }
  }
  */
  
  gimp_progress_init( PLUG_IN_NAME );

  scale = sqrt(select_width*select_width+select_height*select_height) / 2;
  offset = (gint)(scale / 2);

  for( y = select_y1; y < select_y2; y++ ){
    cy = ((gdouble)y - center_y) / scale; 
    for( x = select_x1; x < select_x2; x++ ){
      cx = ((gdouble)x - center_x) / scale;
      angle = floor( atan2(cy,cx) * parameters.division / PI_2 ) 
	* PI_2 / parameters.division + ( PI / parameters.division );
      radius = sqrt((gdouble)(cx*cx+cy*cy));
      xx = x - offset * cos( angle );
      yy = y - offset * sin( angle );
      if( xx < 0 ) xx = 0;
      else if( image_width <= xx ) xx = image_width - 1;
      if( yy < 0 ) yy = 0;
      else if( image_height <= yy ) yy = image_height - 1;
      for( b = 0; b < image_bpp; b++ )
	destpixels[y][x*image_bpp+b] =
	  (1-radius)*pixels[y][x*image_bpp+b] 
	  + radius*pixels[yy][xx*image_bpp+b];
    }
    gimp_pixel_rgn_set_row (&destPR, destpixels[y], 0, y, image_width );
    gimp_progress_update ( (double)( y - select_y1 ) / (double)select_height );
  }
  
  gimp_drawable_flush( drawable );
  gimp_drawable_merge_shadow( drawable->id, TRUE );
  gimp_drawable_update( drawable->id,
			select_x1, select_y1, select_width, select_height );

  for( y = select_y1; y < select_y2; y++ ) free( pixels[y-select_y1] );
  free( pixels );
  for( y = select_y1; y < select_y2; y++ ) free( destpixels[y-select_y1] );
  free( destpixels );
}

/******************************************************************************/

static int dialog_status;

static GtkWidget *entry_division;

static void dialog_destroy_handler( GtkWidget *widget, gpointer *data )
{
  gtk_main_quit();
}

static void dialog_ok_handler( GtkWidget *widget, gpointer *data )
{
  dialog_status = TRUE;

  parameters.division =
    (gint32)atof(gtk_entry_get_text( GTK_ENTRY( entry_division ) ) );

  gtk_widget_destroy( GTK_WIDGET( data ) );
}

static void dialog_cancel_handler( GtkWidget *widget, gpointer *data )
{
  dialog_status = FALSE;
  gtk_widget_destroy( GTK_WIDGET( data ) );
}

/******************************************************************************/

static int dialog( void )
{
  GtkWidget *window;
  
  dialog_status = FALSE;
  
  {
    gint    argc = 1;
    gchar **argv = g_new( gchar *, 1 );
    argv[0] = g_strdup( DIALOG_CAPTION );
    gtk_init( &argc, &argv );
  }

  /* dialog window */
  window = gtk_dialog_new();
  gtk_signal_connect( GTK_OBJECT( window ), "destroy",
		      GTK_SIGNAL_FUNC( dialog_destroy_handler ), NULL );
  gtk_container_border_width( GTK_CONTAINER( window ), 0 );
  gtk_container_border_width( GTK_CONTAINER( GTK_DIALOG( window )->vbox ), 5 );

  {
    /* buttons */
    GtkWidget *button;

    /* ok button */
    button = gtk_button_new_with_label( "OK" );
    gtk_signal_connect_object( GTK_OBJECT( button ), "clicked",
			       GTK_SIGNAL_FUNC( dialog_ok_handler ),
			       GTK_OBJECT( window ) );
    GTK_WIDGET_SET_FLAGS( button, GTK_CAN_DEFAULT );
    gtk_box_pack_start( GTK_BOX( GTK_DIALOG( window )->action_area ),
			button, TRUE, TRUE, 0 );
    gtk_widget_grab_default( button );
    gtk_widget_show( button );
    
    /* cancel button */
    button = gtk_button_new_with_label( "Cancel" );
    gtk_signal_connect_object( GTK_OBJECT( button ), "clicked",
			       GTK_SIGNAL_FUNC( dialog_cancel_handler ),
			       GTK_OBJECT( window )) ;
    gtk_box_pack_start( GTK_BOX( GTK_DIALOG( window )->action_area ),
			button, TRUE, TRUE, 0 );
    gtk_widget_show( button );
  }
  
  {
    /* text boxes */
    GtkWidget *table;
    GtkWidget *label;
    char       buffer[32];
    
    /* table */
    table = gtk_table_new( 1, 2, FALSE );
    gtk_table_set_row_spacings( GTK_TABLE( table ), 5 );
    gtk_table_set_col_spacings( GTK_TABLE( table ), 5 );
    gtk_box_pack_start( GTK_BOX( GTK_DIALOG( window )->vbox ),
			table, TRUE, TRUE, 0 );
    gtk_widget_show( table );
    
    /* tile width */
    label = gtk_label_new( "division: " );
    entry_division = gtk_entry_new();
    sprintf( buffer, "%d", parameters.division );
    gtk_entry_set_text( GTK_ENTRY( entry_division ), buffer );
    gtk_table_attach_defaults( GTK_TABLE( table ), label, 0, 1, 0, 1 );
    gtk_table_attach_defaults( GTK_TABLE( table ), entry_division, 1, 2, 0, 1 );
    gtk_widget_show( label );
    gtk_widget_show( entry_division );
  }

  gtk_widget_show( window );
  gtk_main();

  return dialog_status;
}

/******************************************************************************/