Pileus Git - ~andy/gtk/blob - gdk-pixbuf/io-wbmp.c

   1 /* GdkPixbuf library - Wireless Bitmap image loader
   2  *
   3  * Copyright (C) 2000 Red Hat, Inc.
   4  *
   5  * Authors: Elliot Lee <sopwith@redhat.com
   6  *
   7  * Based on io-bmp.c
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the
  21  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22  * Boston, MA 02111-1307, USA.
  23  */
  24
  25 /*
  26
  27 Known bugs:
  28         * Since this is based off the libgd implementation, no extended headers implemented (not required for a WAP client)
  29 */
  30
  31 #include <config.h>
  32 #include <stdio.h>
  33 #ifdef HAVE_UNISTD_H
  34 #include <unistd.h>
  35 #endif
  36 #include <string.h>
  37 #include "gdk-pixbuf-private.h"
  38 #include "gdk-pixbuf-io.h"
  39
  40 \f
  41
  42 /* Progressive loading */
  43
  44 struct wbmp_progressive_state {
  45   ModulePreparedNotifyFunc prepared_func;
  46   ModuleUpdatedNotifyFunc updated_func;
  47   gpointer user_data;
  48
  49   gboolean need_type : 1;
  50   gboolean need_header : 1;
  51   gboolean need_width : 1;
  52   gboolean need_height : 1;
  53   gboolean needmore : 1;
  54   gboolean call_progressive_updates : 1;
  55
  56   guchar last_buf[16]; /* Just needs to be big enough to hold the largest datum requestable via 'getin' */
  57   guint last_len;
  58
  59   int type;
  60   int width, height, curx, cury;
  61
  62   GdkPixbuf *pixbuf;    /* Our "target" */
  63 };
  64
  65 static gpointer
  66 gdk_pixbuf__wbmp_image_begin_load(ModuleSizeFunc size_func,
  67                                   ModulePreparedNotifyFunc prepared_func,
  68                                   ModuleUpdatedNotifyFunc updated_func,
  69                                   gpointer user_data,
  70                                   GError **error);
  71
  72 static gboolean gdk_pixbuf__wbmp_image_stop_load(gpointer data, GError **error);
  73 static gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data,
  74                                                       const guchar * buf,
  75                                                       guint size,
  76                                                       GError **error);
  77
  78 /*
  79  * func - called when we have pixmap created (but no image data)
  80  * user_data - passed as arg 1 to func
  81  * return context (opaque to user)
  82  */
  83
  84 static gpointer
  85 gdk_pixbuf__wbmp_image_begin_load(ModuleSizeFunc size_func,
  86                                   ModulePreparedNotifyFunc prepared_func,
  87                                   ModuleUpdatedNotifyFunc updated_func,
  88                                   gpointer user_data,
  89                                   GError **error)
  90 {
  91         struct wbmp_progressive_state *context;
  92
  93         context = g_new0(struct wbmp_progressive_state, 1);
  94         context->prepared_func = prepared_func;
  95         context->updated_func = updated_func;
  96         context->user_data = user_data;
  97
  98         context->needmore = context->need_type = context->need_header = context->need_width = context->need_height = TRUE;
  99         context->call_progressive_updates = TRUE;
 100         context->pixbuf = NULL;
 101
 102         return (gpointer) context;
 103 }
 104
 105 /*
 106  * context - returned from image_begin_load
 107  *
 108  * free context, unref gdk_pixbuf
 109  */
 110 static gboolean gdk_pixbuf__wbmp_image_stop_load(gpointer data,
 111                                                  GError **error)
 112 {
 113         struct wbmp_progressive_state *context =
 114             (struct wbmp_progressive_state *) data;
 115
 116         /* FIXME this thing needs to report errors if
 117          * we have unused image data
 118          */
 119
 120         g_return_val_if_fail(context != NULL, TRUE);
 121         if (context->pixbuf)
 122           g_object_unref(context->pixbuf);
 123
 124         g_free(context);
 125
 126         return TRUE;
 127 }
 128
 129 static gboolean
 130 getin(struct wbmp_progressive_state *context, const guchar **buf, guint *buf_size, guchar *ptr, int datum_size)
 131 {
 132   int last_num, buf_num;
 133
 134   if((context->last_len + *buf_size) < datum_size)
 135     return FALSE;
 136
 137   /* We know we can pull it out of there */
 138   last_num = MIN(datum_size, context->last_len);
 139   buf_num = MIN(datum_size-last_num, *buf_size);
 140   memcpy(ptr, context->last_buf, last_num);
 141   memcpy(ptr+last_num, *buf, buf_num);
 142
 143   context->last_len -= last_num;
 144   if(context->last_len)
 145     memmove(context->last_buf, context->last_buf+last_num, context->last_len);
 146   *buf_size -= buf_num;
 147   *buf += buf_num;
 148
 149   return TRUE;
 150 }
 151
 152 static gboolean
 153 save_rest(struct wbmp_progressive_state *context, const guchar *buf, guint buf_size)
 154 {
 155   if(buf_size > (sizeof(context->last_buf) - context->last_len))
 156     return FALSE;
 157
 158   memcpy(context->last_buf+context->last_len, buf, buf_size);
 159   context->last_len += buf_size;
 160
 161   return TRUE;
 162 }
 163
 164 static gboolean
 165 get_mbi(struct wbmp_progressive_state *context, const guchar **buf, guint *buf_size, int *val)
 166 {
 167   guchar intbuf[16];
 168   int i, n;
 169   gboolean rv;
 170
 171   *val = 0;
 172   n = i = 0;
 173   do {
 174     rv = getin(context, buf, buf_size, intbuf+n, 1);
 175     if(!rv)
 176       goto out;
 177     *val <<= 7;
 178     *val |= intbuf[n] & 0x7F;
 179     n++;
 180   } while(n < sizeof(intbuf) && (intbuf[n-1] & 0x80));
 181
 182  out:
 183   if(!rv || (intbuf[n-1] & 0x80))
 184     {
 185       rv = save_rest(context, intbuf, n);
 186
 187       if(!rv)
 188         g_error("Couldn't save_rest of intbuf");
 189       return FALSE;
 190     }
 191
 192   return TRUE;
 193 }
 194
 195 /*
 196  * context - from image_begin_load
 197  * buf - new image data
 198  * size - length of new image data
 199  *
 200  * append image data onto inrecrementally built output image
 201  */
 202 static gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data,
 203                                                       const guchar * buf,
 204                                                       guint size, GError **error)
 205 {
 206         struct wbmp_progressive_state *context =
 207             (struct wbmp_progressive_state *) data;
 208         gboolean bv = FALSE;
 209
 210         do
 211           {
 212             if(context->need_type)
 213               {
 214                 guchar val;
 215
 216                 bv = getin(context, &buf, &size, &val, 1);
 217                 if(bv)
 218                   {
 219                     context->type = val;
 220                     context->need_type = FALSE;
 221                   }
 222               }
 223             else if(context->need_header)
 224               {
 225                 guchar val;
 226
 227                 bv = getin(context, &buf, &size, &val, 1);
 228                 if(bv)
 229                   {
 230                     /* We skip over the extended header - val is unused */
 231                     if(!(val & 0x80))
 232                       context->need_header = FALSE;
 233                   }
 234               }
 235             else if(context->need_width)
 236               {
 237                 bv = get_mbi(context, &buf, &size, &context->width);
 238                 if(bv) {
 239                   context->need_width = FALSE;
 240
 241                   if (context->width <= 0) {
 242                     g_set_error (error,
 243                                  GDK_PIXBUF_ERROR,
 244                                  GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
 245                                  _("Image has zero width"));
 246
 247                     return FALSE;
 248                   }
 249                 }
 250
 251               }
 252             else if(context->need_height)
 253               {
 254                 bv = get_mbi(context, &buf, &size, &context->height);
 255                 if(bv)
 256                   {
 257                     context->need_height = FALSE;
 258
 259                     if (context->height <= 0) {
 260                       g_set_error (error,
 261                                    GDK_PIXBUF_ERROR,
 262                                    GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
 263                                    _("Image has zero height"));
 264
 265                       return FALSE;
 266                     }
 267
 268                     context->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, context->width, context->height);
 269
 270                     if (!context->pixbuf) {
 271                       g_set_error (error,
 272                                    GDK_PIXBUF_ERROR,
 273                                    GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
 274                                    _("Not enough memory to load image"));
 275                       return FALSE;
 276                     }
 277
 278
 279                     if(context->prepared_func)
 280                       context->prepared_func(context->pixbuf, NULL, context->user_data);
 281                   }
 282               }
 283             else if(context->needmore)
 284               {
 285                 int first_row;
 286                 first_row = context->cury;
 287                 for( ; context->cury < context->height; context->cury++, context->curx = 0)
 288                   {
 289                     for( ; context->curx < context->width; context->curx += 8)
 290                       {
 291                         guchar byte;
 292                         guchar *ptr;
 293                         int xoff;
 294                         bv = getin(context, &buf, &size, &byte, 1);
 295                         if(!bv)
 296                           goto out;
 297
 298                         ptr = context->pixbuf->pixels + context->pixbuf->rowstride * context->cury + context->curx * 3;
 299                         for(xoff = 7; xoff >= 0; xoff--, ptr += 3)
 300                           {
 301                             guchar pixval;
 302
 303                             if (context->curx + (7 - xoff) == context->width)
 304                               break;
 305
 306                             if(byte & (1<<xoff))
 307                               pixval = 0xFF;
 308                             else
 309                               pixval = 0x0;
 310
 311                             ptr[0] = ptr[1] = ptr[2] = pixval;
 312                           }
 313                       }
 314                   }
 315                 context->needmore = FALSE;
 316
 317               out:
 318                 if(context->updated_func)
 319                   context->updated_func(context->pixbuf, 0, first_row, context->width, context->cury - first_row + 1,
 320                                         context->user_data);
 321               }
 322             else
 323               bv = FALSE; /* Nothing left to do, stop feeding me data! */
 324
 325           } while(bv);
 326
 327         if(size) {
 328           bv = save_rest(context, buf, size);
 329           if (!bv) {
 330               g_set_error (error,
 331                            GDK_PIXBUF_ERROR,
 332                            GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
 333                            _("Couldn't save the rest"));
 334
 335               return FALSE;
 336           }
 337         }
 338         return TRUE;
 339 }
 340
 341 void
 342 gdk_pixbuf__wbmp_fill_vtable (GdkPixbufModule *module)
 343 {
 344   module->begin_load = gdk_pixbuf__wbmp_image_begin_load;
 345   module->stop_load = gdk_pixbuf__wbmp_image_stop_load;
 346   module->load_increment = gdk_pixbuf__wbmp_image_load_increment;
 347 }