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 #include <unistd.h>
  34 #include <string.h>
  35 #include "gdk-pixbuf-private.h"
  36 #include "gdk-pixbuf-io.h"
  37
  38 \f
  39
  40 /* Progressive loading */
  41
  42 struct wbmp_progressive_state {
  43   ModulePreparedNotifyFunc prepared_func;
  44   ModuleUpdatedNotifyFunc updated_func;
  45   gpointer user_data;
  46
  47   gboolean need_type : 1;
  48   gboolean need_header : 1;
  49   gboolean need_width : 1;
  50   gboolean need_height : 1;
  51   gboolean needmore : 1;
  52   gboolean call_progressive_updates : 1;
  53
  54   guchar last_buf[16]; /* Just needs to be big enough to hold the largest datum requestable via 'getin' */
  55   guint last_len;
  56
  57   int type;
  58   int width, height, curx, cury;
  59
  60   GdkPixbuf *pixbuf;    /* Our "target" */
  61 };
  62
  63 gpointer
  64 gdk_pixbuf__wbmp_image_begin_load(ModulePreparedNotifyFunc prepared_func,
  65                                   ModuleUpdatedNotifyFunc updated_func,
  66                                   ModuleFrameDoneNotifyFunc frame_done_func,
  67                                   ModuleAnimationDoneNotifyFunc
  68                                   anim_done_func, gpointer user_data);
  69
  70 void gdk_pixbuf__wbmp_image_stop_load(gpointer data);
  71 gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data, guchar * buf,
  72                                                guint size);
  73
  74
  75 /* Shared library entry point --> This should be removed when
  76    generic_image_load enters gdk-pixbuf-io. */
  77 GdkPixbuf *gdk_pixbuf__wbmp_image_load(FILE * f)
  78 {
  79         size_t length;
  80         char membuf[4096];
  81         struct wbmp_progressive_state *State;
  82
  83         GdkPixbuf *pb;
  84
  85         State = gdk_pixbuf__wbmp_image_begin_load(NULL, NULL, NULL, NULL, NULL);
  86
  87         while (feof(f) == 0) {
  88                 length = fread(membuf, 1, 4096, f);
  89                 if (length > 0)
  90                   gdk_pixbuf__wbmp_image_load_increment(State,
  91                                                         membuf,
  92                                                         length);
  93
  94         }
  95         if (State->pixbuf != NULL)
  96                 gdk_pixbuf_ref(State->pixbuf);
  97
  98         pb = State->pixbuf;
  99
 100         gdk_pixbuf__wbmp_image_stop_load(State);
 101         return pb;
 102 }
 103
 104 /*
 105  * func - called when we have pixmap created (but no image data)
 106  * user_data - passed as arg 1 to func
 107  * return context (opaque to user)
 108  */
 109
 110 gpointer
 111 gdk_pixbuf__wbmp_image_begin_load(ModulePreparedNotifyFunc prepared_func,
 112                                  ModuleUpdatedNotifyFunc updated_func,
 113                                  ModuleFrameDoneNotifyFunc frame_done_func,
 114                                  ModuleAnimationDoneNotifyFunc
 115                                  anim_done_func, gpointer user_data)
 116 {
 117         struct wbmp_progressive_state *context;
 118
 119         context = g_new0(struct wbmp_progressive_state, 1);
 120         context->prepared_func = prepared_func;
 121         context->updated_func = updated_func;
 122         context->user_data = user_data;
 123
 124         context->needmore = context->need_type = context->need_header = context->need_width = context->need_height = TRUE;
 125         context->call_progressive_updates = TRUE;
 126         context->pixbuf = NULL;
 127
 128         return (gpointer) context;
 129 }
 130
 131 /*
 132  * context - returned from image_begin_load
 133  *
 134  * free context, unref gdk_pixbuf
 135  */
 136 void gdk_pixbuf__wbmp_image_stop_load(gpointer data)
 137 {
 138         struct wbmp_progressive_state *context =
 139             (struct wbmp_progressive_state *) data;
 140
 141         g_return_if_fail(context != NULL);
 142         if (context->pixbuf)
 143           gdk_pixbuf_unref(context->pixbuf);
 144
 145         g_free(context);
 146 }
 147
 148 static gboolean
 149 getin(struct wbmp_progressive_state *context, guchar **buf, guint *buf_size, guchar *ptr, int datum_size)
 150 {
 151   int last_num, buf_num;
 152
 153   if((context->last_len + *buf_size) < datum_size)
 154     return FALSE;
 155
 156   /* We know we can pull it out of there */
 157   last_num = MIN(datum_size, context->last_len);
 158   buf_num = MIN(datum_size-last_num, *buf_size);
 159   memcpy(ptr, context->last_buf, last_num);
 160   memcpy(ptr+last_num, *buf, buf_num);
 161
 162   context->last_len -= last_num;
 163   if(context->last_len)
 164     memmove(context->last_buf, context->last_buf+last_num, context->last_len);
 165   *buf_size -= buf_num;
 166   *buf += buf_num;
 167
 168   return TRUE;
 169 }
 170
 171 static gboolean
 172 save_rest(struct wbmp_progressive_state *context, const guchar *buf, guint buf_size)
 173 {
 174   if(buf_size > (sizeof(context->last_buf) - context->last_len))
 175     return FALSE;
 176
 177   memcpy(context->last_buf+context->last_len, buf, buf_size);
 178   context->last_len += buf_size;
 179
 180   return TRUE;
 181 }
 182
 183 static gboolean
 184 get_mbi(struct wbmp_progressive_state *context, guchar **buf, guint *buf_size, int *val)
 185 {
 186   guchar intbuf[16];
 187   int i, n;
 188   gboolean rv;
 189
 190   *val = 0;
 191   n = i = 0;
 192   do {
 193     rv = getin(context, buf, buf_size, intbuf+n, 1);
 194     if(!rv)
 195       goto out;
 196     *val <<= 7;
 197     *val |= intbuf[n] & 0x7F;
 198     n++;
 199   } while(n < sizeof(intbuf) && (intbuf[n-1] & 0x80));
 200
 201  out:
 202   if(!rv || !(intbuf[n-1] & 0x80))
 203     {
 204       rv = save_rest(context, intbuf, n);
 205
 206       if(!rv)
 207         g_error("Couldn't save_rest of intbuf");
 208       return FALSE;
 209     }
 210
 211   return TRUE;
 212 }
 213
 214 /*
 215  * context - from image_begin_load
 216  * buf - new image data
 217  * size - length of new image data
 218  *
 219  * append image data onto inrecrementally built output image
 220  */
 221 gboolean gdk_pixbuf__wbmp_image_load_increment(gpointer data, guchar * buf,
 222                                               guint size)
 223 {
 224         struct wbmp_progressive_state *context =
 225             (struct wbmp_progressive_state *) data;
 226         gboolean bv;
 227
 228         do
 229           {
 230             if(context->need_type)
 231               {
 232                 guchar val;
 233
 234                 bv = getin(context, &buf, &size, &val, 1);
 235                 if(bv)
 236                   {
 237                     context->type = val;
 238                     context->need_type = FALSE;
 239                   }
 240               }
 241             else if(context->need_header)
 242               {
 243                 guchar val;
 244
 245                 bv = getin(context, &buf, &size, &val, 1);
 246                 if(bv)
 247                   {
 248                     /* We skip over the extended header - val is unused */
 249                     if(!(val & 0x80))
 250                       context->need_header = FALSE;
 251                   }
 252               }
 253             else if(context->need_width)
 254               {
 255                 bv = get_mbi(context, &buf, &size, &context->width);
 256                 if(bv)
 257                   context->need_width = FALSE;
 258               }
 259             else if(context->need_height)
 260               {
 261                 bv = get_mbi(context, &buf, &size, &context->height);
 262                 if(bv)
 263                   {
 264                     context->need_height = FALSE;
 265                     context->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, context->width, context->height);
 266                     if(context->prepared_func)
 267                       context->prepared_func(context->pixbuf, context->user_data);
 268                   }
 269               }
 270             else if(context->needmore)
 271               {
 272                 int first_row;
 273                 first_row = context->cury;
 274                 for( ; context->cury < context->height; context->cury++, context->curx = 0)
 275                   {
 276                     for( ; context->curx < context->width; context->curx += 8)
 277                       {
 278                         guchar byte;
 279                         guchar *ptr;
 280                         int xoff;
 281                         bv = getin(context, &buf, &size, &byte, 1);
 282                         if(!bv)
 283                           goto out;
 284
 285                         ptr = context->pixbuf->pixels + context->pixbuf->rowstride * context->cury + context->curx * 3;
 286                         for(xoff = 0; xoff < 8; xoff++, ptr += 3)
 287                           {
 288                             guchar pixval;
 289
 290                             if(byte & (1<<xoff))
 291                               pixval = 0xFF;
 292                             else
 293                               pixval = 0x0;
 294
 295                             ptr[0] = ptr[1] = ptr[2] = pixval;
 296                           }
 297                       }
 298                   }
 299                 context->needmore = FALSE;
 300
 301               out:
 302                 context->updated_func(context->pixbuf, 0, first_row, context->width, context->cury - first_row + 1,
 303                                       context->user_data);
 304               }
 305             else
 306               bv = FALSE; /* Nothing left to do, stop feeding me data! */
 307
 308           } while(bv);
 309
 310         if(size)
 311           return save_rest(context, buf, size);
 312         else
 313           return context->needmore;
 314 }