Pileus Git - ~andy/gtk/blob - gdk/gdkimage.c

   1 /* GDK - The GIMP Drawing Kit
   2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GTK+ Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #include <config.h>
  28 #include <stdlib.h>
  29 #include <sys/types.h>
  30
  31 #include "gdk.h"                /* For gdk_flush() */
  32 #include "gdkimage.h"
  33 #include "gdkprivate.h"
  34 #include "gdkinternals.h"       /* For scratch_image code */
  35 #include "gdkalias.h"
  36
  37 /**
  38  * gdk_image_ref:
  39  * @image: a #GdkImage
  40  *
  41  * Deprecated function; use g_object_ref() instead.
  42  *
  43  * Return value: the image
  44  **/
  45 GdkImage *
  46 gdk_image_ref (GdkImage *image)
  47 {
  48   return (GdkImage *) g_object_ref (image);
  49 }
  50
  51 /**
  52  * gdk_image_unref:
  53  * @image: a #GdkImage
  54  *
  55  * Deprecated function; use g_object_unref() instead.
  56  *
  57  **/
  58 void
  59 gdk_image_unref (GdkImage *image)
  60 {
  61   g_return_if_fail (GDK_IS_IMAGE (image));
  62
  63   g_object_unref (image);
  64 }
  65
  66 /**
  67  * gdk_image_get:
  68  * @drawable: a #GdkDrawable
  69  * @x: x coordinate in @window
  70  * @y: y coordinate in @window
  71  * @width: width of area in @window
  72  * @height: height of area in @window
  73  *
  74  * This is a deprecated wrapper for gdk_drawable_get_image();
  75  * gdk_drawable_get_image() should be used instead. Or even better: in
  76  * most cases gdk_pixbuf_get_from_drawable() is the most convenient
  77  * choice.
  78  *
  79  * Return value: a new #GdkImage or %NULL
  80  **/
  81 GdkImage*
  82 gdk_image_get (GdkWindow *drawable,
  83                gint       x,
  84                gint       y,
  85                gint       width,
  86                gint       height)
  87 {
  88   g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
  89   g_return_val_if_fail (x >= 0, NULL);
  90   g_return_val_if_fail (y >= 0, NULL);
  91   g_return_val_if_fail (width >= 0, NULL);
  92   g_return_val_if_fail (height >= 0, NULL);
  93
  94   return gdk_drawable_get_image (drawable, x, y, width, height);
  95 }
  96
  97 /**
  98  * gdk_image_set_colormap:
  99  * @image: a #GdkImage
 100  * @colormap: a #GdkColormap
 101  *
 102  * Sets the colormap for the image to the given colormap.  Normally
 103  * there's no need to use this function, images are created with the
 104  * correct colormap if you get the image from a drawable. If you
 105  * create the image from scratch, use the colormap of the drawable you
 106  * intend to render the image to.
 107  **/
 108 void
 109 gdk_image_set_colormap (GdkImage       *image,
 110                         GdkColormap    *colormap)
 111 {
 112   g_return_if_fail (GDK_IS_IMAGE (image));
 113   g_return_if_fail (GDK_IS_COLORMAP (colormap));
 114
 115   if (image->colormap != colormap)
 116     {
 117       if (image->colormap)
 118         g_object_unref (image->colormap);
 119
 120       image->colormap = colormap;
 121       g_object_ref (image->colormap);
 122     }
 123
 124 }
 125
 126 /**
 127  * gdk_image_get_colormap:
 128  * @image: a #GdkImage
 129  *
 130  * Retrieves the colormap for a given image, if it exists.  An image
 131  * will have a colormap if the drawable from which it was created has
 132  * a colormap, or if a colormap was set explicitely with
 133  * gdk_image_set_colormap().
 134  *
 135  * Return value: colormap for the image
 136  **/
 137 GdkColormap *
 138 gdk_image_get_colormap (GdkImage *image)
 139 {
 140   g_return_val_if_fail (GDK_IS_IMAGE (image), NULL);
 141
 142   return image->colormap;
 143 }
 144
 145 /* We have N_REGION GDK_SCRATCH_IMAGE_WIDTH x GDK_SCRATCH_IMAGE_HEIGHT regions divided
 146  * up between n_images different images. possible_n_images gives
 147  * various divisors of N_REGIONS. The reason for allowing this
 148  * flexibility is that we want to create as few images as possible,
 149  * but we want to deal with the abberant systems that have a SHMMAX
 150  * limit less than
 151  *
 152  * GDK_SCRATCH_IMAGE_WIDTH * GDK_SCRATCH_IMAGE_HEIGHT * N_REGIONS * 4 (384k)
 153  *
 154  * (Are there any such?)
 155  */
 156 #define N_REGIONS 6
 157 static const int possible_n_images[] = { 1, 2, 3, 6 };
 158
 159 /* We allocate one GdkScratchImageInfo structure for each
 160  * depth where we are allocating scratch images. (Future: one
 161  * per depth, per display)
 162  */
 163 typedef struct _GdkScratchImageInfo GdkScratchImageInfo;
 164
 165 struct _GdkScratchImageInfo {
 166   gint depth;
 167
 168   gint n_images;
 169   GdkImage *static_image[N_REGIONS];
 170   gint static_image_idx;
 171
 172   /* In order to optimize filling fractions, we simultaneously fill in up
 173    * to three regions of size GDK_SCRATCH_IMAGE_WIDTH * GDK_SCRATCH_IMAGE_HEIGHT: one
 174    * for images that are taller than GDK_SCRATCH_IMAGE_HEIGHT / 2, and must
 175    * be tiled horizontally. One for images that are wider than
 176    * GDK_SCRATCH_IMAGE_WIDTH / 2 and must be tiled vertically, and a third
 177    * for images smaller than GDK_SCRATCH_IMAGE_HEIGHT / 2 x GDK_SCRATCH_IMAGE_WIDTH x 2
 178    * that we tile in horizontal rows.
 179    */
 180   gint horiz_idx;
 181   gint horiz_y;
 182   gint vert_idx;
 183   gint vert_x;
 184
 185   /* tile_y1 and tile_y2 define the horizontal band into
 186    * which we are tiling images. tile_x is the x extent to
 187    * which that is filled
 188    */
 189   gint tile_idx;
 190   gint tile_x;
 191   gint tile_y1;
 192   gint tile_y2;
 193
 194   GdkScreen *screen;
 195 };
 196
 197 static GSList *scratch_image_infos = NULL;
 198
 199 static gboolean
 200 allocate_scratch_images (GdkScratchImageInfo *info,
 201                          gint                 n_images,
 202                          gboolean             shared)
 203 {
 204   gint i;
 205
 206   for (i = 0; i < n_images; i++)
 207     {
 208       info->static_image[i] = _gdk_image_new_for_depth (info->screen,
 209                                                         shared ? GDK_IMAGE_SHARED : GDK_IMAGE_NORMAL,
 210                                                         NULL,
 211                                                         GDK_SCRATCH_IMAGE_WIDTH * (N_REGIONS / n_images),
 212                                                         GDK_SCRATCH_IMAGE_HEIGHT,
 213                                                         info->depth);
 214
 215       if (!info->static_image[i])
 216         {
 217           gint j;
 218
 219           for (j = 0; j < i; j++)
 220             g_object_unref (info->static_image[j]);
 221
 222           return FALSE;
 223         }
 224     }
 225
 226   return TRUE;
 227 }
 228
 229 static GdkScratchImageInfo *
 230 scratch_image_info_for_depth (GdkScreen *screen,
 231                               gint       depth)
 232 {
 233   GSList *tmp_list;
 234   GdkScratchImageInfo *image_info;
 235   gint i;
 236
 237   tmp_list = scratch_image_infos;
 238   while (tmp_list)
 239     {
 240       image_info = tmp_list->data;
 241       if (image_info->depth == depth && image_info->screen == screen)
 242         return image_info;
 243
 244       tmp_list = tmp_list->next;
 245     }
 246
 247   image_info = g_new (GdkScratchImageInfo, 1);
 248
 249   image_info->depth = depth;
 250   image_info->screen = screen;
 251
 252   /* Try to allocate as few possible shared images */
 253   for (i=0; i < G_N_ELEMENTS (possible_n_images); i++)
 254     {
 255       if (allocate_scratch_images (image_info, possible_n_images[i], TRUE))
 256         {
 257           image_info->n_images = possible_n_images[i];
 258           break;
 259         }
 260     }
 261
 262   /* If that fails, just allocate N_REGIONS normal images */
 263   if (i == G_N_ELEMENTS (possible_n_images))
 264     {
 265       allocate_scratch_images (image_info, N_REGIONS, FALSE);
 266       image_info->n_images = N_REGIONS;
 267     }
 268
 269   image_info->static_image_idx = 0;
 270
 271   image_info->horiz_y = GDK_SCRATCH_IMAGE_HEIGHT;
 272   image_info->vert_x = GDK_SCRATCH_IMAGE_WIDTH;
 273   image_info->tile_x = GDK_SCRATCH_IMAGE_WIDTH;
 274   image_info->tile_y1 = image_info->tile_y2 = GDK_SCRATCH_IMAGE_HEIGHT;
 275
 276   scratch_image_infos = g_slist_prepend (scratch_image_infos, image_info);
 277
 278   return image_info;
 279 }
 280
 281 /* Defining NO_FLUSH can cause inconsistent screen updates, but is useful
 282    for performance evaluation. */
 283
 284 #undef NO_FLUSH
 285
 286 #ifdef VERBOSE
 287 static gint sincelast;
 288 #endif
 289
 290 static gint
 291 alloc_scratch_image (GdkScratchImageInfo *image_info)
 292 {
 293   if (image_info->static_image_idx == N_REGIONS)
 294     {
 295 #ifndef NO_FLUSH
 296       gdk_flush ();
 297 #endif
 298 #ifdef VERBOSE
 299       g_print ("flush, %d puts since last flush\n", sincelast);
 300       sincelast = 0;
 301 #endif
 302       image_info->static_image_idx = 0;
 303
 304       /* Mark all regions that we might be filling in as completely
 305        * full, to force new tiles to be allocated for subsequent
 306        * images
 307        */
 308       image_info->horiz_y = GDK_SCRATCH_IMAGE_HEIGHT;
 309       image_info->vert_x = GDK_SCRATCH_IMAGE_WIDTH;
 310       image_info->tile_x = GDK_SCRATCH_IMAGE_WIDTH;
 311       image_info->tile_y1 = image_info->tile_y2 = GDK_SCRATCH_IMAGE_HEIGHT;
 312     }
 313   return image_info->static_image_idx++;
 314 }
 315
 316 /**
 317  * _gdk_image_get_scratch:
 318  * @screen: a #GdkScreen
 319  * @width: desired width
 320  * @height: desired height
 321  * @depth: depth of image
 322  * @x: X location within returned image of scratch image
 323  * @y: Y location within returned image of scratch image
 324  *
 325  * Allocates an image of size width/height, up to a maximum
 326  * of GDK_SCRATCH_IMAGE_WIDTHxGDK_SCRATCH_IMAGE_HEIGHT that is
 327  * suitable to use on @screen.
 328  *
 329  * Return value: a scratch image. This must be used by a
 330  *  call to gdk_image_put() before any other calls to
 331  *  _gdk_image_get_scratch()
 332  **/
 333 GdkImage *
 334 _gdk_image_get_scratch (GdkScreen   *screen,
 335                         gint         width,
 336                         gint         height,
 337                         gint         depth,
 338                         gint        *x,
 339                         gint        *y)
 340 {
 341   GdkScratchImageInfo *image_info;
 342   GdkImage *image;
 343   gint idx;
 344
 345   g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);
 346
 347   image_info = scratch_image_info_for_depth (screen, depth);
 348
 349   if (width >= (GDK_SCRATCH_IMAGE_WIDTH >> 1))
 350     {
 351       if (height >= (GDK_SCRATCH_IMAGE_HEIGHT >> 1))
 352         {
 353           idx = alloc_scratch_image (image_info);
 354           *x = 0;
 355           *y = 0;
 356         }
 357       else
 358         {
 359           if (height + image_info->horiz_y > GDK_SCRATCH_IMAGE_HEIGHT)
 360             {
 361               image_info->horiz_idx = alloc_scratch_image (image_info);
 362               image_info->horiz_y = 0;
 363             }
 364           idx = image_info->horiz_idx;
 365           *x = 0;
 366           *y = image_info->horiz_y;
 367           image_info->horiz_y += height;
 368         }
 369     }
 370   else
 371     {
 372       if (height >= (GDK_SCRATCH_IMAGE_HEIGHT >> 1))
 373         {
 374           if (width + image_info->vert_x > GDK_SCRATCH_IMAGE_WIDTH)
 375             {
 376               image_info->vert_idx = alloc_scratch_image (image_info);
 377               image_info->vert_x = 0;
 378             }
 379           idx = image_info->vert_idx;
 380           *x = image_info->vert_x;
 381           *y = 0;
 382           /* using 3 and -4 would be slightly more efficient on 32-bit machines
 383              with > 1bpp displays */
 384           image_info->vert_x += (width + 7) & -8;
 385         }
 386       else
 387         {
 388           if (width + image_info->tile_x > GDK_SCRATCH_IMAGE_WIDTH)
 389             {
 390               image_info->tile_y1 = image_info->tile_y2;
 391               image_info->tile_x = 0;
 392             }
 393           if (height + image_info->tile_y1 > GDK_SCRATCH_IMAGE_HEIGHT)
 394             {
 395               image_info->tile_idx = alloc_scratch_image (image_info);
 396               image_info->tile_x = 0;
 397               image_info->tile_y1 = 0;
 398               image_info->tile_y2 = 0;
 399             }
 400           if (height + image_info->tile_y1 > image_info->tile_y2)
 401             image_info->tile_y2 = height + image_info->tile_y1;
 402           idx = image_info->tile_idx;
 403           *x = image_info->tile_x;
 404           *y = image_info->tile_y1;
 405           image_info->tile_x += (width + 7) & -8;
 406         }
 407     }
 408   image = image_info->static_image[idx * image_info->n_images / N_REGIONS];
 409   *x += GDK_SCRATCH_IMAGE_WIDTH * (idx % (N_REGIONS / image_info->n_images));
 410 #ifdef VERBOSE
 411   g_print ("index %d, x %d, y %d (%d x %d)\n", idx, *x, *y, width, height);
 412   sincelast++;
 413 #endif
 414   return image;
 415 }
 416
 417 GdkImage*
 418 gdk_image_new (GdkImageType  type,
 419                GdkVisual    *visual,
 420                gint          width,
 421                gint          height)
 422 {
 423   return _gdk_image_new_for_depth (gdk_visual_get_screen (visual), type,
 424                                    visual, width, height, -1);
 425 }
 426
 427 #define __GDK_IMAGE_C__
 428 #include "gdkaliasdef.c"