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