pjs/cmd/gnomefe/gnome-img.c

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

/* 
   gnomeimg.c --- gnome functions for fe
                  specific images stuff.
*/

#define JMC_INIT_IMGCB_ID

#include "xp_core.h"
#include "structs.h"
#include "ntypes.h"

#include "libimg.h"
#include "il_util.h"
#include "prtypes.h"
#include "g-util.h"
#include "g-types.h"
#include "gnomefe.h"
#include "g-html-view.h"
#include <gdk/gdk.h>
#include <gdk/gdkx.h>
#include <X11/X.h>

#define HOWMANY(x, r)     (((x) + ((r) - 1)) / (r))
#define ROUNDUP(x, r)     (HOWMANY(x, r) * (r))

typedef struct 
{
  GdkPixmap *x_pixmap;
  GdkGC *gc;
  int32 x_clip_offset, y_clip_offset;
  XP_Rect *fill_rect;
} fe_FillTiledPixmapClosure;

typedef struct 
{
  GdkPixmap *img_x_pixmap;
  GdkPixmap *mask_x_pixmap;
  GdkWindow *drawable;
  GdkGC *gc;
  GdkGC *mask_gc;
  int32 img_x_offset, img_y_offset;
  XP_Rect *fill_rect;
} fe_FillPixmapClosure;

static GdkPixmap *
fe_TiledMaskWithClipRegion(GdkWindow *drawable,
                           GdkPixmap *mask_x_pixmap,
                           unsigned int width, unsigned int height,
                           int x_tile_offset, int y_tile_offset,
                           int x_clip_offset, int y_clip_offset,
                           GdkRegion **clip_region);

static void
fe_DrawMaskedImageWithClipRegion(GdkWindow *drawable,
                                 GdkPixmap *img_x_pixmap, GdkPixmap *mask_x_pixmap,
                                 unsigned int width, unsigned int height,
                                 int img_x_offset, int img_y_offset,
                                 int x_offset, int y_offset,
                                 GdkRegion **clip_region);

static void
fe_FillTiledPixmapRectFunc(void *closure, XP_Rect *clip_rect)
{
    fe_FillTiledPixmapClosure *fill_closure =
        (fe_FillTiledPixmapClosure*)closure;
    GdkPixmap *x_pixmap = fill_closure->x_pixmap;
    GdkGC *gc = fill_closure->gc;
    int32 x_clip_offset = fill_closure->x_clip_offset;
    int32 y_clip_offset = fill_closure->y_clip_offset;
    XP_Rect *fill_rect = fill_closure->fill_rect;
    XP_Rect sub_rect;
    uint32 sub_rect_width, sub_rect_height;

    /* Convert the clip rect's coordinates to be relative to the pixmap's
       origin. */
    XP_OffsetRect(clip_rect, x_clip_offset, y_clip_offset);
    XP_IntersectRect(clip_rect, fill_rect, &sub_rect);

    /* Compute the width and height of the actual area to be drawn.  If either
       dimension is zero, we have nothing to do. */
    sub_rect_width = sub_rect.right - sub_rect.left;
    sub_rect_height = sub_rect.bottom - sub_rect.top;
    if (!sub_rect_width || !sub_rect_height)
        return;

    /* Draw a sub_rect of the temporary mask. */
    gdk_draw_rectangle(x_pixmap, gc, TRUE, sub_rect.left, sub_rect.top,
                       sub_rect_width, sub_rect_height);
}

static void
fe_FillPixmapRectFunc(void *closure, XP_Rect *clip_rect)
{
    fe_FillPixmapClosure *fill_closure = (fe_FillPixmapClosure*)closure;
    GdkPixmap *img_x_pixmap = fill_closure->img_x_pixmap;
    GdkPixmap *mask_x_pixmap = fill_closure->mask_x_pixmap;
    GdkWindow *drawable = fill_closure->drawable;
    GdkGC *gc = fill_closure->gc;
    GdkGC *mask_gc = fill_closure->mask_gc;
    int32 img_x_offset = fill_closure->img_x_offset;
    int32 img_y_offset = fill_closure->img_y_offset;
    XP_Rect *fill_rect = fill_closure->fill_rect;
    XP_Rect sub_rect;
    GdkPixmap *tmp_pixmap;
    unsigned long flags;
    int32 sub_rect_x_offset, sub_rect_y_offset; /* Offsets wrt image origin. */
    uint32 sub_rect_width, sub_rect_height;

    /* Rectangle coordinates are all relative to the drawable origin. */
    XP_IntersectRect(clip_rect, fill_rect, &sub_rect);

    /* Compute the width and height of the actual area to be drawn.  If either
       dimension is zero, we have nothing to do. */
    sub_rect_width = sub_rect.right - sub_rect.left;
    sub_rect_height = sub_rect.bottom - sub_rect.top;
    if (!sub_rect_width || !sub_rect_height)
        return;

    /* Compute the offsets, wrt the image origin, of the area to be drawn. */
    sub_rect_x_offset = sub_rect.left - img_x_offset;
    sub_rect_y_offset = sub_rect.top - img_y_offset;

    /* Create a temporary mask pixmap which is the size of the area to be
       drawn. */
    tmp_pixmap = gdk_pixmap_new(drawable, sub_rect_width, sub_rect_height,
                                1);
    gdk_window_copy_area(tmp_pixmap, mask_gc, 0, 0, mask_x_pixmap,
                         sub_rect_x_offset, sub_rect_y_offset,
                         sub_rect_width, sub_rect_height);

    /* Use the temporary mask as the GC's clip mask, instead of using the
       entire image mask.  For complicated masks, this has a significant
       performance benefit on X servers which convert clip_masks to
       rectangle lists. */
    gdk_gc_set_clip_mask(gc, tmp_pixmap);
    gdk_gc_set_clip_origin(gc, sub_rect.left, sub_rect.top);

    /* Draw a sub_rect of the image. */
    gdk_window_copy_area(drawable, gc, sub_rect.left, sub_rect.top,
                         img_x_pixmap,
                         sub_rect_x_offset, sub_rect_y_offset,
                         sub_rect_width, sub_rect_height);
                         
    /* Clean up. */
    gdk_pixmap_unref(tmp_pixmap);
}

JMC_PUBLIC_API(void)
_IMGCB_init(struct IMGCB* self, JMCException* *exception)
{
  printf ("_IMGCB_init (nothing to do)\n");
}

JMC_PUBLIC_API(void*)
_IMGCB_getBackwardCompatibleInterface(struct IMGCB* self,
				      const JMCInterfaceID* iid,
				      JMCException* *exception)
{
  printf ("_IMGCB_getBackwardCompatibleInterface (nothing to do)\n");
}

JMC_PUBLIC_API(void)
_IMGCB_NewPixmap(IMGCB* img_cb, jint op, void *dpy_cx, jint width, jint height,
		 IL_Pixmap *image, IL_Pixmap *mask) 
{
  MWContext *context = (MWContext *)dpy_cx; /* XXX This should be the FE's
                                               display context. */
  uint8 img_depth;
  NI_PixmapHeader *img_header = &image->header;
  NI_PixmapHeader *mask_header = mask ? &mask->header : NULL;
  fe_PixmapClientData *img_client_data, *mask_client_data = NULL;
  MozHTMLView *view = 0;
  unsigned int visual_depth;
  fe_Drawable *fe_drawable;

  /*
  printf ("_IMGCB_NewPixmap (context %p, image %p, width %d, height %d)\n",
	  context, image, (int) width, (int) height);
  */
  /* Allocate the client data structures for the IL_Pixmaps. */
  img_client_data = XP_NEW_ZAP(fe_PixmapClientData);
  if (!img_client_data) {
    image->bits = NULL;
    mask->bits = NULL;
    return;
  }
  if (mask) {
    mask_client_data = XP_NEW_ZAP(fe_PixmapClientData);
    if (!mask_client_data) {
            image->bits = NULL;
            mask->bits = NULL;
            return;
    }
  }
  
  /* try to get the required display parameters from the html view */
  view = find_html_view(context);
  XP_ASSERT(view);
  fe_drawable = view->drawable;
  visual_depth = gdk_visual_get_best_depth();
  
  /* Override the image and mask dimensions with the requested target
     dimensions.  This instructs the image library to do any necessary
     scaling. */
  img_header->width = width;
  img_header->height = height;
  if (mask) {
    mask_header->width = width;
    mask_header->height = height;
  }
  
  /* Override the image colorspace with the display colorspace.  This
     instructs the image library to decode to the display colorspace
     instead of decoding to the image's source colorspace. */
  IL_ReleaseColorSpace(img_header->color_space);
  img_header->color_space = context->color_space;
  IL_AddRefToColorSpace(img_header->color_space);
  
  /* Compute the number of bytes per scan line for the image and mask,
     and make sure it is quadlet aligned. */

  img_depth = img_header->color_space->pixmap_depth;
  XP_ASSERT(img_depth == visual_depth);
  img_header->widthBytes = (img_header->width * img_depth + 7) / 8;
  img_header->widthBytes = ROUNDUP(img_header->widthBytes, 4);
  if (mask) {
    mask_header->widthBytes = (mask_header->width + 7) / 8;
    mask_header->widthBytes = ROUNDUP(mask_header->widthBytes, 4);
  }

  /* Allocate memory for the image bits, and for the mask bits (if
     required.) */
  image->bits = calloc(img_header->widthBytes * img_header->height, 1);
  if (!image->bits)
    return;
  if (mask) {
    mask->bits = calloc(mask_header->widthBytes * mask_header->height, 1);
    if (!mask->bits) {
      free(image->bits);
      image->bits = NULL;
      return;
    }
  }
  
  /* Create an X pixmap for the image, and for the mask (if required.) */
  img_client_data->gdk_pixmap =
    gdk_pixmap_new(view->scrolled_window->window,
                   img_header->width,
                   img_header->height,
                   visual_depth);
  /*
  printf("\tNewpixmap: width, height = %d, %d\n",
         img_header->width,
	 img_header->height);
  */
  if (mask)
    {
      mask_client_data->gdk_pixmap =
        gdk_pixmap_new(view->scrolled_window->window,
                       mask_header->width,
                       mask_header->height,
                       1);
      /*
      printf("Newbitmap: width, height = %d, %d\n",
             mask_header->width,
             mask_header->height);
      */
    }
  
  /* Fill in the pixmap client_data. */
  image->client_data = (void *)img_client_data;
  if (mask)
    mask->client_data = (void *)mask_client_data;
}

JMC_PUBLIC_API(void)
_IMGCB_UpdatePixmap(IMGCB* img_cb, jint op, void* dpy_cx, IL_Pixmap* pixmap,
		    jint x_offset, jint y_offset, jint width, jint height)
{
  uint32 widthBytes;
  MWContext *context = (MWContext *)dpy_cx; /* XXX This should be the FE's
                                                 display context. */
  unsigned int visual_depth;
  unsigned int pixmap_depth;  /* Depth of the IL_Pixmap. */
  Visual *visual;
  Pixmap x_pixmap;
  Display *dpy;
  XImage *x_image;
  GC gc;
  XGCValues gcv;
  IL_ColorSpace *color_space = pixmap->header.color_space;
  char *bits;
  fe_PixmapClientData *pixmap_client_data;
  fe_Drawable *fe_drawable;
  MozHTMLView *view = 0;
  GdkPixmap   *gdk_pixmap;
  GdkImage    *gdk_image;
  GdkGC       *gdk_gc;
  GdkGCValues *gdkgc_values;

  /*
  printf ("_IMGCB_UpdatePixmap (context %p, image %p, width %d, height %d)\n",
	  context, pixmap, (int)width, (int)height) ;
  */
  if (!context)
    return;

  /* get the client data */
  pixmap_client_data = (fe_PixmapClientData *)pixmap->client_data;
  view = find_html_view(context);
  XP_ASSERT(view);
  fe_drawable = view->drawable;

  gdk_pixmap = pixmap_client_data->gdk_pixmap;

  /* try to get the required display parameters from the pixmap */
  visual_depth = gdk_visual_get_best_depth();
  dpy = GDK_WINDOW_XDISPLAY(pixmap_client_data->gdk_pixmap);
  visual = GDK_VISUAL_XVISUAL(gnomefe_visual);
  
  /* Check for zero dimensions. */
  if (width == 0 || height == 0)
    return;
  
  /* Get the depth of the IL_Pixmap.  This should be the same as the
     visual_pixmap_depth if the IL_Pixmap is an image, or 1 if the
     IL_Pixmap is a mask. */
  pixmap_depth = color_space->pixmap_depth;

  widthBytes = pixmap->header.widthBytes;
  bits = (unsigned char *)pixmap->bits + widthBytes * y_offset;

  x_image = XCreateImage(dpy, visual,
                         ((pixmap_depth == 1) ? 1 : visual_depth),
                         ((pixmap_depth == 1) ? XYPixmap : ZPixmap),
                         x_offset,                   /* offset */
                         bits,
                         width,
                         height,
                         8,                          /* bitmap_pad */
                         widthBytes);                /* bytes_per_line */

  if (pixmap_depth == 1) {
    /* Image library always places pixels left-to-right MSB to LSB */
    x_image->bitmap_bit_order = MSBFirst;
    
    /* This definition doesn't depend on client byte ordering
       because the image library ensures that the bytes in
       bitmask data are arranged left to right on the screen,
       low to high address in memory. */
    x_image->byte_order = MSBFirst;
  }
  else {
#if defined(IS_LITTLE_ENDIAN)
    x_image->byte_order = LSBFirst;
#elif defined (IS_BIG_ENDIAN)
    x_image->byte_order = MSBFirst;
#else
    ERROR! Endianness is unknown;
#endif
  }
  
  pixmap_client_data = (fe_PixmapClientData *)pixmap->client_data;
  x_pixmap = GDK_WINDOW_XWINDOW(pixmap_client_data->gdk_pixmap);
  
  memset(&gcv, ~0, sizeof(XGCValues));
  gcv.function = GXcopy;
  
  /* The pixmap_depth does not correspond to that of the GCs in the
     cache, so create a new GC. */
  gc = XCreateGC(dpy, x_pixmap, GCFunction, &gcv);
  
  XPutImage(dpy, x_pixmap, gc, x_image, x_offset, 0, x_offset,
            y_offset, width, height);
  
  XFreeGC(dpy, gc);
  x_image->data = 0;          /* Don't free the IL_Pixmap's bits. */
  XDestroyImage(x_image);
}

JMC_PUBLIC_API(void)
_IMGCB_ControlPixmapBits(IMGCB* img_cb, jint op, void* dpy_cx,
                         IL_Pixmap* pixmap, IL_PixmapControl message)
{
  if (message == IL_RELEASE_BITS) {
    printf ("_IMGCB_ControlPixmapBits (image complete)\n");
  }
}

JMC_PUBLIC_API(void)
_IMGCB_DestroyPixmap(IMGCB* img_cb, jint op, void* dpy_cx, IL_Pixmap* pixmap)
{
  fe_PixmapClientData *pixmap_client_data;

  /* printf ("_IMGCB_DestroyPixmap\n"); */
  pixmap_client_data = (fe_PixmapClientData *)pixmap->client_data;
  if (!pixmap_client_data)
    return;
  if (pixmap_client_data->gdk_pixmap)
    gdk_pixmap_unref(pixmap_client_data->gdk_pixmap);
  if (pixmap->bits) {
    free(pixmap->bits);
    pixmap->bits = NULL;
  }
}



JMC_PUBLIC_API(void)
_IMGCB_DisplayPixmap(IMGCB* img_cb, jint op, void* dpy_cx, IL_Pixmap* image, 
                     IL_Pixmap* mask, jint x, jint y, jint x_offset,
                     jint y_offset, jint width, jint height, jint j, jint k)
{

  MWContext *context = (MWContext *)dpy_cx; /* XXX This should be the FE's
                                                 display context. */
  
  int32 img_x_offset, img_y_offset; /* Offset of image in drawable. */
  int32 rect_x_offset, rect_y_offset; /* Offset of update rect in
                                           drawable. */
  NI_PixmapHeader *img_header = &image->header;
  uint32 img_width = img_header->width;	/* Image width. */
  uint32 img_height = img_header->height; /* Image height. */

  fe_Drawable *fe_drawable = find_html_view(context)->drawable;
  GdkDrawable *drawable = fe_drawable->drawable;
  fe_PixmapClientData *img_client_data, *mask_client_data;

  GdkPixmap *img_x_pixmap=NULL, *mask_x_pixmap=NULL;
  GdkGC *gc;
  XP_Bool tiling_required = FALSE;
  GdkWindow * window = (GdkWindow *)fe_drawable->drawable;

  /*
  printf ("_IMGCB_DisplayPixmap (context %p, image %p, width %d, height %d)\n",
	  context, image, (int)width, (int)height);
  */
				/* Check for zero display area. */
  if (width == 0 || height == 0)
    return;
  
				/* Retrieve the server pixmaps. */
  img_client_data = (fe_PixmapClientData *)image->client_data;
  if (!img_client_data)
    return;
  img_x_pixmap = img_client_data->gdk_pixmap;
  if (!img_x_pixmap)
    return;
  if (mask) {
    mask_client_data = (fe_PixmapClientData *)mask->client_data;
    mask_x_pixmap = mask_client_data->gdk_pixmap;
  }
  
  /* Determine whether tiling is required. */
  if ((x_offset + width > img_width) || (y_offset + height > img_height))
    tiling_required = TRUE;
  
  /* Compute the offset into the drawable of the image origin. */
  img_x_offset = x - find_html_view(context)->doc_x +
    fe_drawable->x_origin;
  img_y_offset = y - find_html_view(context)->doc_y +
    fe_drawable->y_origin;
  
  /* Compute the offset into the drawable for the area to be drawn. */
  rect_x_offset = img_x_offset + x_offset;
  rect_y_offset = img_y_offset + y_offset;
  
  /* Do the actual drawing.  There are several cases to be dealt with:
     transparent vs non-transparent, tiled vs non-tiled and clipped by
     compositor's clip region vs not clipped. */

  if (mask) /* image is transparent */
    {
      if (tiling_required)
        {
          /* Offsets are measured wrt the origin of the tiled mask to
             be generated. */
          int x_tile_offset = img_x_offset - rect_x_offset;
          int y_tile_offset = img_y_offset - rect_y_offset;
          GdkPixmap *tmp_pixmap = NULL;
          GdkGC *tmp_gc;
          /* Create the mask by tiling the mask_x_pixmap and computing
             the intersection with the compositor's clip region. */
          tmp_pixmap = 
            fe_TiledMaskWithClipRegion(fe_drawable->drawable,
                                       mask_x_pixmap,
                                       width, height,
                                       x_tile_offset, y_tile_offset,
                                       -rect_x_offset, -rect_y_offset,
                                       fe_drawable->clip_region);
          tmp_gc = gdk_gc_new(window);
          gdk_gc_set_fill(tmp_gc, GDK_TILED);
          gdk_gc_set_tile(tmp_gc, img_x_pixmap);
          gdk_gc_set_ts_origin(tmp_gc, img_x_offset, img_y_offset);
          gdk_gc_set_clip_mask(tmp_gc, tmp_pixmap);
          gdk_gc_set_clip_origin(tmp_gc, rect_x_offset, rect_y_offset);
          gdk_draw_rectangle(window, tmp_gc, TRUE, rect_x_offset, rect_y_offset,
                             width, height);
          gdk_gc_unref(tmp_gc);
          gdk_pixmap_unref(tmp_pixmap);
        }
    else
      {
#if 0
        if (fe_drawable->clip_region)
          {
            fe_DrawMaskedImageWithClipRegion(window,
                                             img_x_pixmap, mask_x_pixmap,
                                             width, height,
                                             img_x_offset, img_y_offset,
                                             x_offset, y_offset,
                                             fe_drawable->clip_region);
          }
#endif
#if 1
        gc = gdk_gc_new(window);
        gdk_gc_set_clip_mask(gc, mask_x_pixmap);
        gdk_gc_set_clip_origin(gc, img_x_offset, img_y_offset);
        gdk_draw_pixmap(drawable, gc, img_x_pixmap,
                        x_offset, y_offset,
                        rect_x_offset, rect_y_offset,
                        width, height);
#endif
      }
    }
  else
    { /* image is not transparent */
      if (tiling_required)
        {
          GdkGC *tmp_gc;
          tmp_gc = gdk_gc_new(window);
          gdk_gc_set_fill(tmp_gc, GDK_TILED);
          gdk_gc_set_tile(tmp_gc, img_x_pixmap);
          gdk_gc_set_ts_origin(tmp_gc, img_x_offset, img_y_offset);
          gdk_draw_rectangle(window, tmp_gc, TRUE,
                             rect_x_offset, rect_y_offset, width, height);
          gdk_gc_unref(tmp_gc);
        }
      else /* tiling not required */
        {
          GdkGC *tmp_gc;
          tmp_gc = gdk_gc_new(window);
          gdk_window_copy_area(window, tmp_gc, rect_x_offset, rect_y_offset,
                               img_x_pixmap, x_offset, y_offset, width, height);
          gdk_gc_unref(tmp_gc);
        }
    }      
#if 0
  gc = gdk_gc_new(window);
  if (mask)
    {
      gdk_gc_set_clip_mask(gc, mask_x_pixmap);
      gdk_gc_set_clip_origin(gc, img_x_offset, img_y_offset);
    }
  else if ((fe_drawable->clip_region) && (tiling_required == FALSE))
    {
      /*printf("draw_pixmap: using clip region at %p\n", fe_drawable->clip_region); */
      gdk_gc_set_clip_region(gc, *(GdkRegion **)fe_drawable->clip_region);
    }
  if (tiling_required) 
    {
      GdkPixmap *tmp_pixmap;
      int cur_x = 0;
      int cur_y = 0;
      int draw_width = 0;
      int draw_height = 0;
      tmp_pixmap = gdk_pixmap_new((GdkWindow *)fe_drawable->drawable,
                                  width, height,
                                  img_header->color_space->pixmap_depth);
      printf("DrawPixmap: Create tmp image width %d height %d from img_width %d img_height %d x_offset %d y_offset %d rect_x_offset %d rect_y_offset %d\n",
             width, height, img_width, img_height, x_offset, y_offset, rect_x_offset, rect_y_offset);
      while (cur_y < height)
        {
          while (cur_x < width)
            {
              if ((width - cur_x) < img_width)
                draw_width = (width - cur_x);
              else
                draw_width = img_width;
              if ((height - cur_y) < img_height)
                draw_height = ( height - cur_y );
              else
                draw_height = img_height;
              printf("DrawPixmap: drawing tile at cur_x %d cur_y %d draw_width %d draw_height %d\n",
                     cur_x, cur_y, draw_width, draw_height);
              gdk_draw_pixmap(tmp_pixmap, gc, img_x_pixmap,
                              x_offset, y_offset,
                              cur_x, cur_y,
                              draw_width, draw_height);
              cur_x += img_width;
            }
          cur_y += img_height;
          cur_x = 0;
        }
      gdk_draw_pixmap(drawable, gc, tmp_pixmap,
                      x_offset, y_offset,
                      rect_x_offset, rect_y_offset,
                      width, height);
    }
  else {
    /*
    printf("draw_pixmap (xo %d, yo %d, rxo %d, ryo %d, w %d, h %d)\n",
           x_offset, y_offset,
           rect_x_offset, rect_y_offset,
           width, height);
    */
    gdk_draw_pixmap(drawable, gc, img_x_pixmap,
                    x_offset, y_offset,
                    rect_x_offset, rect_y_offset,
                    width, height);
  }
  
				/* Clean up. */
  gdk_gc_destroy(gc);
#endif

}

JMC_PUBLIC_API(void)
_IMGCB_GetIconDimensions(IMGCB* img_cb, jint op, void* dpy_cx, int* width,
                         int* height, jint icon_number)
{
  printf ("_IMGCB_GetIconDimensions\n");
}

JMC_PUBLIC_API(void)
_IMGCB_DisplayIcon(IMGCB* img_cb, jint op, void* dpy_cx, jint x, jint y,
                   jint icon_number)
{
  printf ("_IMGCB_DisplayIcon\n");
}

/* Mocha image group observer callback. */
void
FE_MochaImageGroupObserver(XP_Observable observable, XP_ObservableMsg message,
                           void *message_data, void *closure)
{
  printf("FE_MochaImageGroupObserver (empty)\n");
}

/* Generate a tiled mask for the case where the fe_Drawable has a clip
   region.  Offset arguments are wrt the origin of the tiled mask. */
static GdkPixmap *
fe_TiledMaskWithClipRegion(GdkWindow *drawable,
                           GdkPixmap *mask_x_pixmap,
                           unsigned int width, unsigned int height,
                           int x_tile_offset, int y_tile_offset,
                           int x_clip_offset, int y_clip_offset,
                           GdkRegion **clip_region)
{
  GdkGC *gc;
  XGCValues gcv;
  unsigned long flags;
  XP_Rect fill_rect;
  GdkPixmap *ret_x_pixmap;
  fe_FillTiledPixmapClosure fill_closure;

  
  ret_x_pixmap = gdk_pixmap_new(drawable, width, height, 1);
    
  /* The pixmap must be cleared since it may cover areas which do not
     belong to the clip region. */
  gc = gdk_gc_new(drawable);
  gdk_gc_set_function(gc, GDK_CLEAR);
  gdk_draw_rectangle(ret_x_pixmap, gc, TRUE, 0, 0, width, height);

    /* Set up the GC. */
  gdk_gc_set_function(gc, GDK_COPY);
  gdk_gc_set_fill(gc, GDK_TILED);
  gdk_gc_set_tile(gc, mask_x_pixmap);
  gdk_gc_set_ts_origin(gc, x_tile_offset, y_tile_offset);

  /* Tile the mask_pixmap into the tiled_mask_pixmap, but only do so for
     areas in the clip region's rectangle list. */
  fill_rect.left = 0;
  fill_rect.top = 0;
  fill_rect.right = width;
  fill_rect.bottom = height;
  fill_closure.fill_rect = &fill_rect;
  fill_closure.x_pixmap = ret_x_pixmap;
  fill_closure.gc = gc;
  fill_closure.x_clip_offset = x_clip_offset;
  fill_closure.y_clip_offset = y_clip_offset;
  FE_ForEachRectInRegion(clip_region, fe_FillTiledPixmapRectFunc,
                         &fill_closure);
  
  /* Clean up. */
  gdk_gc_unref(gc);

  return ret_x_pixmap;
}

/* Draw the masked image for each rectangle in the compositor's clip region.
   x_offset and y_offset are wrt the image origin, while rect_x_offset and
   rect_y_offset are wrt the drawable origin. */
static void
fe_DrawMaskedImageWithClipRegion(GdkWindow *drawable,
                                 GdkPixmap *img_x_pixmap, GdkPixmap *mask_x_pixmap,
                                 unsigned int width, unsigned int height,
                                 int img_x_offset, int img_y_offset,
                                 int x_offset, int y_offset,
                                 GdkRegion **clip_region)
{
  GdkGC *gc;
  GdkGC *mask_gc;
  XP_Rect fill_rect;
  fe_FillPixmapClosure fill_closure;

  /* Set up the GCs. */
  gc =  gdk_gc_new(drawable);
  mask_gc = gdk_gc_new(drawable);

  /* Draw the masked image into the drawable, but only do so for areas in
     the clip region's rectangle list. */
  fill_rect.left = img_x_offset + x_offset;
  fill_rect.top = img_y_offset + y_offset;
  fill_rect.right = fill_rect.left + width;
  fill_rect.bottom = fill_rect.top + height;
  fill_closure.fill_rect = &fill_rect;
  fill_closure.img_x_pixmap = img_x_pixmap;
  fill_closure.mask_x_pixmap = mask_x_pixmap;
  fill_closure.drawable = drawable;
  fill_closure.gc = gc;
  fill_closure.mask_gc = mask_gc;
  fill_closure.img_x_offset = img_x_offset;
  fill_closure.img_y_offset = img_y_offset;
  FE_ForEachRectInRegion(clip_region, fe_FillPixmapRectFunc, &fill_closure);
  
  /* Clean up. */
  gdk_gc_unref(gc);
  gdk_gc_unref(mask_gc);
}