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