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(ModulePreparedNotifyFunc prepared_func,
  67                                   ModuleUpdatedNotifyFunc updated_func,
  68                                   ModuleFrameDoneNotifyFunc frame_done_func,
  69                                   ModuleAnimationDoneNotifyFunc
  70                                   anim_done_func, gpointer user_data,
  71                                   GError **error);
  72
  73 static gboolean gdk_pixbuf__wbmp_image_stop_load(gpointer data, GError **error);
  74 static gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data,
  75                                                       const guchar * buf,
  76                                                       guint size,
  77                                                       GError **error);
  78
  79
  80 /* Shared library entry point --> This should be removed when
  81    generic_image_load enters gdk-pixbuf-io. */
  82 static GdkPixbuf *gdk_pixbuf__wbmp_image_load(FILE * f, GError **error)
  83 {
  84         size_t length;
  85         char membuf[4096];
  86         struct wbmp_progressive_state *State;
  87
  88         GdkPixbuf *pb;
  89
  90         State = gdk_pixbuf__wbmp_image_begin_load(NULL, NULL, NULL, NULL, NULL,
  91                                                   error);
  92
  93         if (State == NULL)
  94           return NULL;
  95
  96         while (feof(f) == 0) {
  97                 length = fread(membuf, 1, 4096, f);
  98                 if (length > 0)
  99                   gdk_pixbuf__wbmp_image_load_increment(State,
 100                                                         membuf,
 101                                                         length,
 102                                                         error);
 103
 104         }
 105         if (State->pixbuf != NULL)
 106                 gdk_pixbuf_ref(State->pixbuf);
 107
 108         pb = State->pixbuf;
 109
 110         gdk_pixbuf__wbmp_image_stop_load(State, NULL);
 111         return pb;
 112 }
 113
 114 /*
 115  * func - called when we have pixmap created (but no image data)
 116  * user_data - passed as arg 1 to func
 117  * return context (opaque to user)
 118  */
 119
 120 static gpointer
 121 gdk_pixbuf__wbmp_image_begin_load(ModulePreparedNotifyFunc prepared_func,
 122                                   ModuleUpdatedNotifyFunc updated_func,
 123                                   ModuleFrameDoneNotifyFunc frame_done_func,
 124                                   ModuleAnimationDoneNotifyFunc
 125                                   anim_done_func, gpointer user_data,
 126                                   GError **error)
 127 {
 128         struct wbmp_progressive_state *context;
 129
 130         context = g_new0(struct wbmp_progressive_state, 1);
 131         context->prepared_func = prepared_func;
 132         context->updated_func = updated_func;
 133         context->user_data = user_data;
 134
 135         context->needmore = context->need_type = context->need_header = context->need_width = context->need_height = TRUE;
 136         context->call_progressive_updates = TRUE;
 137         context->pixbuf = NULL;
 138
 139         return (gpointer) context;
 140 }
 141
 142 /*
 143  * context - returned from image_begin_load
 144  *
 145  * free context, unref gdk_pixbuf
 146  */
 147 static gboolean gdk_pixbuf__wbmp_image_stop_load(gpointer data,
 148                                                  GError **error)
 149 {
 150         struct wbmp_progressive_state *context =
 151             (struct wbmp_progressive_state *) data;
 152
 153         /* FIXME this thing needs to report errors if
 154          * we have unused image data
 155          */
 156
 157         g_return_val_if_fail(context != NULL, TRUE);
 158         if (context->pixbuf)
 159           gdk_pixbuf_unref(context->pixbuf);
 160
 161         g_free(context);
 162
 163         return TRUE;
 164 }
 165
 166 static gboolean
 167 getin(struct wbmp_progressive_state *context, guchar **buf, guint *buf_size, guchar *ptr, int datum_size)
 168 {
 169   int last_num, buf_num;
 170
 171   if((context->last_len + *buf_size) < datum_size)
 172     return FALSE;
 173
 174   /* We know we can pull it out of there */
 175   last_num = MIN(datum_size, context->last_len);
 176   buf_num = MIN(datum_size-last_num, *buf_size);
 177   memcpy(ptr, context->last_buf, last_num);
 178   memcpy(ptr+last_num, *buf, buf_num);
 179
 180   context->last_len -= last_num;
 181   if(context->last_len)
 182     memmove(context->last_buf, context->last_buf+last_num, context->last_len);
 183   *buf_size -= buf_num;
 184   *buf += buf_num;
 185
 186   return TRUE;
 187 }
 188
 189 static gboolean
 190 save_rest(struct wbmp_progressive_state *context, const guchar *buf, guint buf_size)
 191 {
 192   if(buf_size > (sizeof(context->last_buf) - context->last_len))
 193     return FALSE;
 194
 195   memcpy(context->last_buf+context->last_len, buf, buf_size);
 196   context->last_len += buf_size;
 197
 198   return TRUE;
 199 }
 200
 201 static gboolean
 202 get_mbi(struct wbmp_progressive_state *context, guchar **buf, guint *buf_size, int *val)
 203 {
 204   guchar intbuf[16];
 205   int i, n;
 206   gboolean rv;
 207
 208   *val = 0;
 209   n = i = 0;
 210   do {
 211     rv = getin(context, buf, buf_size, intbuf+n, 1);
 212     if(!rv)
 213       goto out;
 214     *val <<= 7;
 215     *val |= intbuf[n] & 0x7F;
 216     n++;
 217   } while(n < sizeof(intbuf) && (intbuf[n-1] & 0x80));
 218
 219  out:
 220   if(!rv || (intbuf[n-1] & 0x80))
 221     {
 222       rv = save_rest(context, intbuf, n);
 223
 224       if(!rv)
 225         g_error("Couldn't save_rest of intbuf");
 226       return FALSE;
 227     }
 228
 229   return TRUE;
 230 }
 231
 232 /*
 233  * context - from image_begin_load
 234  * buf - new image data
 235  * size - length of new image data
 236  *
 237  * append image data onto inrecrementally built output image
 238  */
 239 static gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data,
 240                                                       const guchar * buf,
 241                                                       guint size, GError **error)
 242 {
 243         struct wbmp_progressive_state *context =
 244             (struct wbmp_progressive_state *) data;
 245         gboolean bv = FALSE;
 246
 247         do
 248           {
 249             if(context->need_type)
 250               {
 251                 guchar val;
 252
 253                 bv = getin(context, &buf, &size, &val, 1);
 254                 if(bv)
 255                   {
 256                     context->type = val;
 257                     context->need_type = FALSE;
 258                   }
 259               }
 260             else if(context->need_header)
 261               {
 262                 guchar val;
 263
 264                 bv = getin(context, &buf, &size, &val, 1);
 265                 if(bv)
 266                   {
 267                     /* We skip over the extended header - val is unused */
 268                     if(!(val & 0x80))
 269                       context->need_header = FALSE;
 270                   }
 271               }
 272             else if(context->need_width)
 273               {
 274                 bv = get_mbi(context, &buf, &size, &context->width);
 275                 if(bv)
 276                   context->need_width = FALSE;
 277               }
 278             else if(context->need_height)
 279               {
 280                 bv = get_mbi(context, &buf, &size, &context->height);
 281                 if(bv)
 282                   {
 283                     context->need_height = FALSE;
 284                     context->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, context->width, context->height);
 285                     g_assert(context->pixbuf);
 286
 287                     if(context->prepared_func)
 288                       context->prepared_func(context->pixbuf, context->user_data);
 289                   }
 290               }
 291             else if(context->needmore)
 292               {
 293                 int first_row;
 294                 first_row = context->cury;
 295                 for( ; context->cury < context->height; context->cury++, context->curx = 0)
 296                   {
 297                     for( ; context->curx < context->width; context->curx += 8)
 298                       {
 299                         guchar byte;
 300                         guchar *ptr;
 301                         int xoff;
 302                         bv = getin(context, &buf, &size, &byte, 1);
 303                         if(!bv)
 304                           goto out;
 305
 306                         ptr = context->pixbuf->pixels + context->pixbuf->rowstride * context->cury + context->curx * 3;
 307                         for(xoff = 7; xoff >= 0; xoff--, ptr += 3)
 308                           {
 309                             guchar pixval;
 310
 311                             if(byte & (1<<xoff))
 312                               pixval = 0xFF;
 313                             else
 314                               pixval = 0x0;
 315
 316                             ptr[0] = ptr[1] = ptr[2] = pixval;
 317                           }
 318                       }
 319                   }
 320                 context->needmore = FALSE;
 321
 322               out:
 323                 context->updated_func(context->pixbuf, 0, first_row, context->width, context->cury - first_row + 1,
 324                                       context->user_data);
 325               }
 326             else
 327               bv = FALSE; /* Nothing left to do, stop feeding me data! */
 328
 329           } while(bv);
 330
 331         if(size)
 332           return save_rest(context, buf, size);
 333         else
 334           return context->needmore;
 335 }
 336
 337 void
 338 gdk_pixbuf__wbmp_fill_vtable (GdkPixbufModule *module)
 339 {
 340   module->load = gdk_pixbuf__wbmp_image_load;
 341   module->begin_load = gdk_pixbuf__wbmp_image_begin_load;
 342   module->stop_load = gdk_pixbuf__wbmp_image_stop_load;
 343   module->load_increment = gdk_pixbuf__wbmp_image_load_increment;
 344 }