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                                   gpointer user_data,
  69                                   GError **error);
  70
  71 static gboolean gdk_pixbuf__wbmp_image_stop_load(gpointer data, GError **error);
  72 static gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data,
  73                                                       const guchar * buf,
  74                                                       guint size,
  75                                                       GError **error);
  76
  77
  78 /* Shared library entry point --> This should be removed when
  79    generic_image_load enters gdk-pixbuf-io. */
  80 static GdkPixbuf *gdk_pixbuf__wbmp_image_load(FILE * f, GError **error)
  81 {
  82         size_t length;
  83         char membuf[4096];
  84         struct wbmp_progressive_state *State;
  85
  86         GdkPixbuf *pb;
  87
  88         State = gdk_pixbuf__wbmp_image_begin_load(NULL, NULL, NULL,
  89                                                   error);
  90
  91         if (State == NULL)
  92           return NULL;
  93
  94         while (feof(f) == 0) {
  95                 length = fread(membuf, 1, 4096, f);
  96                 if (length > 0)
  97                   gdk_pixbuf__wbmp_image_load_increment(State,
  98                                                         membuf,
  99                                                         length,
 100                                                         error);
 101
 102         }
 103         if (State->pixbuf != NULL)
 104                 gdk_pixbuf_ref(State->pixbuf);
 105
 106         pb = State->pixbuf;
 107
 108         gdk_pixbuf__wbmp_image_stop_load(State, NULL);
 109         return pb;
 110 }
 111
 112 /*
 113  * func - called when we have pixmap created (but no image data)
 114  * user_data - passed as arg 1 to func
 115  * return context (opaque to user)
 116  */
 117
 118 static gpointer
 119 gdk_pixbuf__wbmp_image_begin_load(ModulePreparedNotifyFunc prepared_func,
 120                                   ModuleUpdatedNotifyFunc updated_func,
 121                                   gpointer user_data,
 122                                   GError **error)
 123 {
 124         struct wbmp_progressive_state *context;
 125
 126         context = g_new0(struct wbmp_progressive_state, 1);
 127         context->prepared_func = prepared_func;
 128         context->updated_func = updated_func;
 129         context->user_data = user_data;
 130
 131         context->needmore = context->need_type = context->need_header = context->need_width = context->need_height = TRUE;
 132         context->call_progressive_updates = TRUE;
 133         context->pixbuf = NULL;
 134
 135         return (gpointer) context;
 136 }
 137
 138 /*
 139  * context - returned from image_begin_load
 140  *
 141  * free context, unref gdk_pixbuf
 142  */
 143 static gboolean gdk_pixbuf__wbmp_image_stop_load(gpointer data,
 144                                                  GError **error)
 145 {
 146         struct wbmp_progressive_state *context =
 147             (struct wbmp_progressive_state *) data;
 148
 149         /* FIXME this thing needs to report errors if
 150          * we have unused image data
 151          */
 152
 153         g_return_val_if_fail(context != NULL, TRUE);
 154         if (context->pixbuf)
 155           gdk_pixbuf_unref(context->pixbuf);
 156
 157         g_free(context);
 158
 159         return TRUE;
 160 }
 161
 162 static gboolean
 163 getin(struct wbmp_progressive_state *context, guchar **buf, guint *buf_size, guchar *ptr, int datum_size)
 164 {
 165   int last_num, buf_num;
 166
 167   if((context->last_len + *buf_size) < datum_size)
 168     return FALSE;
 169
 170   /* We know we can pull it out of there */
 171   last_num = MIN(datum_size, context->last_len);
 172   buf_num = MIN(datum_size-last_num, *buf_size);
 173   memcpy(ptr, context->last_buf, last_num);
 174   memcpy(ptr+last_num, *buf, buf_num);
 175
 176   context->last_len -= last_num;
 177   if(context->last_len)
 178     memmove(context->last_buf, context->last_buf+last_num, context->last_len);
 179   *buf_size -= buf_num;
 180   *buf += buf_num;
 181
 182   return TRUE;
 183 }
 184
 185 static gboolean
 186 save_rest(struct wbmp_progressive_state *context, const guchar *buf, guint buf_size)
 187 {
 188   if(buf_size > (sizeof(context->last_buf) - context->last_len))
 189     return FALSE;
 190
 191   memcpy(context->last_buf+context->last_len, buf, buf_size);
 192   context->last_len += buf_size;
 193
 194   return TRUE;
 195 }
 196
 197 static gboolean
 198 get_mbi(struct wbmp_progressive_state *context, guchar **buf, guint *buf_size, int *val)
 199 {
 200   guchar intbuf[16];
 201   int i, n;
 202   gboolean rv;
 203
 204   *val = 0;
 205   n = i = 0;
 206   do {
 207     rv = getin(context, buf, buf_size, intbuf+n, 1);
 208     if(!rv)
 209       goto out;
 210     *val <<= 7;
 211     *val |= intbuf[n] & 0x7F;
 212     n++;
 213   } while(n < sizeof(intbuf) && (intbuf[n-1] & 0x80));
 214
 215  out:
 216   if(!rv || (intbuf[n-1] & 0x80))
 217     {
 218       rv = save_rest(context, intbuf, n);
 219
 220       if(!rv)
 221         g_error("Couldn't save_rest of intbuf");
 222       return FALSE;
 223     }
 224
 225   return TRUE;
 226 }
 227
 228 /*
 229  * context - from image_begin_load
 230  * buf - new image data
 231  * size - length of new image data
 232  *
 233  * append image data onto inrecrementally built output image
 234  */
 235 static gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data,
 236                                                       const guchar * buf,
 237                                                       guint size, GError **error)
 238 {
 239         struct wbmp_progressive_state *context =
 240             (struct wbmp_progressive_state *) data;
 241         gboolean bv = FALSE;
 242
 243         do
 244           {
 245             if(context->need_type)
 246               {
 247                 guchar val;
 248
 249                 bv = getin(context, &buf, &size, &val, 1);
 250                 if(bv)
 251                   {
 252                     context->type = val;
 253                     context->need_type = FALSE;
 254                   }
 255               }
 256             else if(context->need_header)
 257               {
 258                 guchar val;
 259
 260                 bv = getin(context, &buf, &size, &val, 1);
 261                 if(bv)
 262                   {
 263                     /* We skip over the extended header - val is unused */
 264                     if(!(val & 0x80))
 265                       context->need_header = FALSE;
 266                   }
 267               }
 268             else if(context->need_width)
 269               {
 270                 bv = get_mbi(context, &buf, &size, &context->width);
 271                 if(bv)
 272                   context->need_width = FALSE;
 273               }
 274             else if(context->need_height)
 275               {
 276                 bv = get_mbi(context, &buf, &size, &context->height);
 277                 if(bv)
 278                   {
 279                     context->need_height = FALSE;
 280                     context->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, context->width, context->height);
 281                     g_assert(context->pixbuf);
 282
 283                     if(context->prepared_func)
 284                       context->prepared_func(context->pixbuf, NULL, context->user_data);
 285                   }
 286               }
 287             else if(context->needmore)
 288               {
 289                 int first_row;
 290                 first_row = context->cury;
 291                 for( ; context->cury < context->height; context->cury++, context->curx = 0)
 292                   {
 293                     for( ; context->curx < context->width; context->curx += 8)
 294                       {
 295                         guchar byte;
 296                         guchar *ptr;
 297                         int xoff;
 298                         bv = getin(context, &buf, &size, &byte, 1);
 299                         if(!bv)
 300                           goto out;
 301
 302                         ptr = context->pixbuf->pixels + context->pixbuf->rowstride * context->cury + context->curx * 3;
 303                         for(xoff = 7; xoff >= 0; xoff--, ptr += 3)
 304                           {
 305                             guchar pixval;
 306
 307                             if(byte & (1<<xoff))
 308                               pixval = 0xFF;
 309                             else
 310                               pixval = 0x0;
 311
 312                             ptr[0] = ptr[1] = ptr[2] = pixval;
 313                           }
 314                       }
 315                   }
 316                 context->needmore = FALSE;
 317
 318               out:
 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           return save_rest(context, buf, size);
 329         else
 330           return context->needmore;
 331 }
 332
 333 void
 334 gdk_pixbuf__wbmp_fill_vtable (GdkPixbufModule *module)
 335 {
 336   module->load = gdk_pixbuf__wbmp_image_load;
 337   module->begin_load = gdk_pixbuf__wbmp_image_begin_load;
 338   module->stop_load = gdk_pixbuf__wbmp_image_stop_load;
 339   module->load_increment = gdk_pixbuf__wbmp_image_load_increment;
 340 }