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