/*
 * Image.c -- Image support routines.
 *
 * Authors		: Patrick LECOANET
 * Creation date	: Wed Dec  8 11:04:44 1999
 */

/*
 *  Copyright (c) 1999 CENA, Patrick Lecoanet --
 *
 * This code is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This code 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this code; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */


#include <malloc.h>

#include "Types.h"
#include "Image.h"


static const char rcsid[] = "$Id$";
static const char compile_id[] = "$Compile: " __FILE__ " " __DATE__ " " __TIME__ " $";


/*
 * Key used to index the bitmap_masks hash table.
 */
typedef struct {
  Display	*dpy;
  Pixmap	bitmap;
} BitmapKey;

typedef struct _ImagePixmap {
  Display		*dpy;
  Pixmap		pixmap;
  struct _ImagePixmap	*next;
} ImagePixmap;


static Tcl_HashTable	image_bits;
static Tcl_HashTable	bitmap_masks;

 
/*
 **********************************************************************************
 *
 * GetImageBits --
 *
 **********************************************************************************
 */
ImageBits *
GetImageBits(RadarWindow	win,
	     RadarImage		image)
{
  static int	inited = 0;
  Tcl_HashEntry	*entry;
  XImage	*im1, *im2, *mask;
  Pixmap	pmap;
  Display	*dpy = Tk_Display(win);
  int		depth = Tk_Depth(win);
  int		x, y, new, width, height;
  XGCValues	values;
  GC		gc;
  ImageBits	*im_bits;
  RadarBool	full_mask=True;
  
  if (!inited) {
    Tcl_InitHashTable(&image_bits, TCL_ONE_WORD_KEYS);
    inited = 1;
  }
  entry = Tcl_FindHashEntry(&image_bits, (char *) image);
  if (entry != NULL) {
    im_bits = (ImageBits *) Tcl_GetHashValue(entry);
  }
  else {
    Tk_SizeOfImage(image, &width, &height);
    im_bits = (ImageBits *) RadarMalloc(sizeof(ImageBits));
    im_bits->pixmaps = NULL;
    pmap = XCreatePixmap(dpy, RadarWindowId(win), width, height, depth);

    values.foreground = 0;
    gc = XCreateGC(dpy, pmap, GCForeground, &values);
    XFillRectangle(dpy, pmap, gc, 0, 0, width, height);
    Tk_RedrawImage(image, 0, 0, width, height, pmap, 0, 0);
    im_bits->pixels = im1 = XGetImage(dpy, pmap, 0, 0, width, height, ~0L, ZPixmap);
    im_bits->width = width;
    im_bits->height = height;
    
    values.foreground = 1;
    XChangeGC(dpy, gc, GCForeground, &values);
    XFillRectangle(dpy, pmap, gc, 0, 0, width, height);
    XFreeGC(dpy, gc);
    Tk_RedrawImage(image, 0, 0, width, height, pmap, 0, 0);
    im2 = XGetImage(dpy, pmap, 0, 0, width, height, ~0L, ZPixmap);
    XFreePixmap(dpy, pmap);

    /*
     * The image structure can be setup locally (TODO).
     */
    pmap = XCreatePixmap(dpy, RadarWindowId(win), width, height, 1);
    values.foreground = 0;
    gc = XCreateGC(dpy, pmap, GCForeground, &values);
    XFillRectangle(dpy, pmap, gc, 0, 0, width, height);
    XFreeGC(dpy, gc);
    mask = XGetImage(dpy, pmap, 0, 0, width, height, 1, XYPixmap);
    XFreePixmap(dpy, pmap);

    for (x = 0; x < width; x++) {
      for (y = 0; y < height; y++) {
	if (XGetPixel(im1, x, y) == XGetPixel(im2, x, y)) {
	  XPutPixel(mask, x, y, 1L);
	}
	else {
	  full_mask = False;
	}
      }
    }

    XDestroyImage(im2);
    if (full_mask) {
      XDestroyImage(mask);
      im_bits->mask = RadarUnspecifiedPattern;
    }
    else {
      im_bits->mask = mask;
    }
	
    entry = Tcl_CreateHashEntry(&image_bits, (char *) image, &new);
    Tcl_SetHashValue(entry, (ClientData) im_bits);
  }

  return im_bits;
}

void
InvalidateImage(RadarImage	image)
{
  Tcl_HashEntry	*entry;
  ImageBits	*im_bits;
  ImagePixmap	*im_pmap, *next_im_pmap;
  
  /*
   * Destroy the image entry and wait the cache fault to
   * reload the new one.
   */
  entry = Tcl_FindHashEntry(&image_bits, (char *) image);
  if (entry != NULL) {
    im_bits = (ImageBits *) Tcl_GetHashValue(entry);
    XDestroyImage(im_bits->pixels);
    if (im_bits->mask) {
      XDestroyImage(im_bits->mask);
    }
    im_pmap = im_bits->pixmaps;
    while (im_pmap) {
      next_im_pmap = im_pmap->next;
      XFreePixmap(im_pmap->dpy, im_pmap->pixmap);
      RadarFree(im_pmap);
      im_pmap = next_im_pmap;
    }
    RadarFree(im_bits);
    Tcl_DeleteHashEntry(entry);
  }
}


/*
 **********************************************************************************
 *
 * GetImagePixmap --
 *
 **********************************************************************************
 */
Pixmap
GetImagePixmap(RadarWindow	win,
	       RadarImage	image)
{
  ImageBits	*im_bits;
  Display	*dpy = Tk_Display(win);
  int		depth = Tk_Depth(win);
  ImagePixmap	*im_pmap, *next_im_pmap;
  Pixmap	pixmap;

  im_bits = GetImageBits(win, image);
  im_pmap = next_im_pmap = im_bits->pixmaps;
  while (next_im_pmap && (im_pmap->dpy != dpy)) {
    im_pmap = next_im_pmap;
    next_im_pmap = next_im_pmap->next;
  }
  if (!im_pmap || (im_pmap->dpy != dpy)) {
    next_im_pmap = (ImagePixmap *) RadarMalloc(sizeof(ImagePixmap));
    next_im_pmap->next = NULL;
    next_im_pmap->dpy = dpy;
    pixmap = XCreatePixmap(dpy, RadarWindowId(win),
			   im_bits->width, im_bits->height, depth);
    Tk_RedrawImage(image, 0, 0, im_bits->width, im_bits->height, pixmap, 0, 0);
    next_im_pmap->pixmap = pixmap;
    if (im_pmap) {
      im_pmap->next = next_im_pmap;
    }
    else {
      im_bits->pixmaps = next_im_pmap;
    }
  }
  else {
    pixmap = im_pmap->pixmap;
  }

  return pixmap;
}


/*
 **********************************************************************************
 *
 * GetBitmapMask --
 *
 **********************************************************************************
 */
XImage *
GetBitmapMask(Display	*dpy,
	      Pixmap	bitmap)
{
  static int	inited = 0;
  BitmapKey	key;
  Tcl_HashEntry	*entry;
  XImage	*mask;
  int		w, h, new;
  
  if (!inited) {
    Tcl_InitHashTable(&bitmap_masks, (sizeof(Display *)+sizeof(Pixmap)) / sizeof(int));
    inited = 1;
  }
  key.dpy = dpy;
  key.bitmap = bitmap;
  entry = Tcl_FindHashEntry(&bitmap_masks, (char *) &key);
  if (entry != NULL) {
    mask = (XImage *) Tcl_GetHashValue(entry);
  }
  else {
    Tk_SizeOfBitmap(dpy, bitmap, &w, &h);
    mask = XGetImage(dpy, bitmap, 0, 0, w, h, 1L, XYPixmap);
    key.dpy = dpy;
    key.bitmap = bitmap;
    entry = Tcl_CreateHashEntry(&bitmap_masks, (char *) &key, &new);
    Tcl_SetHashValue(entry, (ClientData) mask);
  }

  return mask;
}