io-bmp.c 36.5 KB
Newer Older
1
/* -*- mode: C; c-file-style: "linux" -*- */
2 3 4
/* GdkPixbuf library - Windows Bitmap image loader
 *
 * Copyright (C) 1999 The Free Software Foundation
Mark Crichton's avatar
Mark Crichton committed
5
 *
6 7 8 9
 * Authors: Arjan van de Ven <arjan@fenrus.demon.nl>
 *          Federico Mena-Quintero <federico@gimp.org>
 *
 * Based on io-ras.c
Mark Crichton's avatar
Mark Crichton committed
10 11
 *
 * This library is free software; you can redistribute it and/or
12
 * modify it under the terms of the GNU Lesser General Public
Mark Crichton's avatar
Mark Crichton committed
13 14 15 16 17 18
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19
 * Lesser General Public License for more details.
Mark Crichton's avatar
Mark Crichton committed
20
 *
21
 * You should have received a copy of the GNU Lesser General Public
22 23 24
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
Mark Crichton's avatar
Mark Crichton committed
25 26 27 28
 */

#include <config.h>
#include <stdio.h>
Tor Lillqvist's avatar
Tor Lillqvist committed
29
#ifdef HAVE_UNISTD_H
30
#include <unistd.h>
Tor Lillqvist's avatar
Tor Lillqvist committed
31
#endif
32
#include <string.h>
33 34
#include "gdk-pixbuf-private.h"
#include "gdk-pixbuf-io.h"
35

Matthias Clasen's avatar
Matthias Clasen committed
36
#define DUMPBIH 0
37

38

39

40 41 42 43 44 45
#if 0
/* If these structures were unpacked, they would define the two headers of the
 * BMP file.  After them comes the palette, and then the image data.
 *
 * We do not use these structures; we just keep them here for reference.
 */
46
struct BitmapFileHeader {
47 48 49 50
	guint16 magic;
	guint32 file_size;
	guint32 reserved;
	guint32 data_offset;
51 52 53
};

struct BitmapInfoHeader {
54 55 56 57 58 59 60 61 62 63 64
	guint32 header_size;
	guint32 width;
	guint32 height;
	guint16 planes;
	guint16 bpp;
	guint32 compression;
	guint32 data_size;
	guint32 x_ppm;
	guint32 y_ppm;
	guint32 n_colors;
	guint32 n_important_colors;
65
};
66
#endif
67

68
/* Compression values */
69 70 71 72 73 74

#define BI_RGB 0
#define BI_RLE8 1
#define BI_RLE4 2
#define BI_BITFIELDS 3

75 76 77 78 79 80 81 82 83
/* State machine */
typedef enum {
	READ_STATE_HEADERS,	/* Reading the bitmap file header and bitmap info header */
	READ_STATE_PALETTE,	/* Reading the palette */
	READ_STATE_BITMASKS,	/* Reading the bitmasks for BI_BITFIELDS */
	READ_STATE_DATA,	/* Reading the actual image data */
	READ_STATE_ERROR,	/* An error occurred; further data will be ignored */
	READ_STATE_DONE		/* Done reading the image; further data will be ignored */
} ReadState;
84

85 86 87
/*

DumpBIH printf's the values in a BitmapInfoHeader to the screen, for
88 89 90 91
debugging purposes.

*/
#if DUMPBIH
92
static void DumpBIH(unsigned char *BIH)
93
{
94
	printf("biSize      = %i \n",
95 96
	       (int) (BIH[3] << 24) + (BIH[2] << 16) + (BIH[1] << 8) +
	       (BIH[0]));
97
	printf("biWidth     = %i \n",
98 99
	       (int) (BIH[7] << 24) + (BIH[6] << 16) + (BIH[5] << 8) +
	       (BIH[4]));
100
	printf("biHeight    = %i \n",
101
	       (int) (BIH[11] << 24) + (BIH[10] << 16) + (BIH[9] << 8) +
102
	       (BIH[8]));
103 104
	printf("biPlanes    = %i \n", (int) (BIH[13] << 8) + (BIH[12]));
	printf("biBitCount  = %i \n", (int) (BIH[15] << 8) + (BIH[14]));
105
	printf("biCompress  = %i \n",
106
	       (int) (BIH[19] << 24) + (BIH[18] << 16) + (BIH[17] << 8) +
107 108
	       (BIH[16]));
	printf("biSizeImage = %i \n",
109
	       (int) (BIH[23] << 24) + (BIH[22] << 16) + (BIH[21] << 8) +
110 111
	       (BIH[20]));
	printf("biXPels     = %i \n",
112
	       (int) (BIH[27] << 24) + (BIH[26] << 16) + (BIH[25] << 8) +
113 114
	       (BIH[24]));
	printf("biYPels     = %i \n",
115
	       (int) (BIH[31] << 24) + (BIH[30] << 16) + (BIH[29] << 8) +
116 117
	       (BIH[28]));
	printf("biClrUsed   = %i \n",
118
	       (int) (BIH[35] << 24) + (BIH[34] << 16) + (BIH[33] << 8) +
119 120
	       (BIH[32]));
	printf("biClrImprtnt= %i \n",
121
	       (int) (BIH[39] << 24) + (BIH[38] << 16) + (BIH[37] << 8) +
122 123
	       (BIH[36]));
}
124 125 126
#endif
/* struct headerpair contains the decoded width/height/depth info for
   the current bitmap */
127

128
struct headerpair {
129 130 131
	guint32 size;
	gint32 width;
	gint32 height;
132
	guint depth;
133
	guint Negative;		/* Negative = 1 -> top down BMP,
134
				   Negative = 0 -> bottom up BMP */
135
	guint  n_colors;
136
};
137

138 139
/* Data needed for the "state" during decompression */
struct bmp_compression_state {
140
	gint phase;
141 142 143 144
	gint run;
	gint count;
	gint x, y;
	guchar *p;
145
};
146 147 148 149

/* Progressive loading */

struct bmp_progressive_state {
150
	GdkPixbufModuleSizeFunc size_func;
151 152
	GdkPixbufModulePreparedFunc prepared_func;
	GdkPixbufModuleUpdatedFunc updated_func;
153 154
	gpointer user_data;

155 156
	ReadState read_state;

157 158
	guint LineWidth;
	guint Lines;		/* # of finished lines */
159

160
	guchar *buff;
161
	guint BufferSize;
162
	guint BufferPadding;
163
	guint BufferDone;
164 165

	guchar (*Colormap)[3];
166

167
	gint Type;		/*
168
				   32 = RGB + alpha
169
				   24 = RGB
170
				   16 = RGB
171 172
				   4  = 4 bpp colormapped
				   8  = 8 bpp colormapped
173
				   1  = 1 bit bitonal
174
				 */
175
	guint Compressed;
176
	struct bmp_compression_state compr;
177 178 179 180


	struct headerpair Header;	/* Decoded (BE->CPU) header */

181 182 183 184
	/* Bit masks, shift amounts, and significant bits for BI_BITFIELDS coding */
	int r_mask, r_shift, r_bits;
	int g_mask, g_shift, g_bits;
	int b_mask, b_shift, b_bits;
185
	int a_mask, a_shift, a_bits;
186 187 188 189

	GdkPixbuf *pixbuf;	/* Our "target" */
};

190
static gpointer
191 192 193
gdk_pixbuf__bmp_image_begin_load(GdkPixbufModuleSizeFunc size_func,
                                 GdkPixbufModulePreparedFunc prepared_func,
				 GdkPixbufModuleUpdatedFunc updated_func,
Havoc Pennington's avatar
Havoc Pennington committed
194
                                 gpointer user_data,
Havoc Pennington's avatar
Havoc Pennington committed
195
                                 GError **error);
Federico Mena Quintero's avatar
Federico Mena Quintero committed
196

197 198 199 200 201
static gboolean gdk_pixbuf__bmp_image_stop_load(gpointer data, GError **error);
static gboolean gdk_pixbuf__bmp_image_load_increment(gpointer data,
                                                     const guchar * buf,
                                                     guint size,
                                                     GError **error);
202

Mark Crichton's avatar
Mark Crichton committed
203

204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220
/* Picks up a 32-bit little-endian integer starting at the specified location.
 * Does it by hand instead of dereferencing a simple (gint *) cast due to
 * alignment constraints many platforms.
 */
static int
lsb_32 (guchar *src)
{
	return src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
}

/* Same as above, but for 16-bit little-endian integers. */
static short
lsb_16 (guchar *src)
{
	return src[0] | (src[1] << 8);
}

221 222 223
static gboolean grow_buffer (struct bmp_progressive_state *State,
                             GError **error)
{
224 225 226 227 228 229 230 231 232 233 234 235 236
  guchar *tmp;

  if (State->BufferSize == 0) {
    g_set_error (error,
		 GDK_PIXBUF_ERROR,
		 GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
		 _("BMP image has bogus header data"));
    State->read_state = READ_STATE_ERROR;
    return FALSE;
  }

  tmp = g_try_realloc (State->buff, State->BufferSize);

237
  if (!tmp) {
238 239 240 241 242 243 244
    g_set_error (error,
		 GDK_PIXBUF_ERROR,
		 GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
		 _("Not enough memory to load bitmap image"));
    State->read_state = READ_STATE_ERROR;
    return FALSE;
  }
245

246
  State->buff = tmp;
247 248 249
  return TRUE;
}

250 251 252 253 254
static gboolean
decode_bitmasks (guchar *buf,
		 struct bmp_progressive_state *State, 
		 GError **error);

255 256 257
static gboolean DecodeHeader(unsigned char *BFH, unsigned char *BIH,
                             struct bmp_progressive_state *State,
                             GError **error)
258
{
259 260
	gint clrUsed;

261
        /* FIXME this is totally unrobust against bogus image data. */
262 263
	if (State->BufferSize < lsb_32 (&BIH[0]) + 14) {
		State->BufferSize = lsb_32 (&BIH[0]) + 14;
264
		if (!grow_buffer (State, error))
Matthias Clasen's avatar
Matthias Clasen committed
265
			return FALSE;
266 267 268
		return TRUE;
	}

269 270
#if DUMPBIH
	DumpBIH(BIH);
271
#endif    
272

273
	State->Header.size = lsb_32 (&BIH[0]);
274 275 276 277 278 279 280 281 282 283 284 285 286 287
	if (State->Header.size == 124) {
                /* BMP v5 */
		State->Header.width = lsb_32 (&BIH[4]);
		State->Header.height = lsb_32 (&BIH[8]);
		State->Header.depth = lsb_16 (&BIH[14]);
		State->Compressed = lsb_32 (&BIH[16]);
	} else if (State->Header.size == 108) {
                /* BMP v4 */
		State->Header.width = lsb_32 (&BIH[4]);
		State->Header.height = lsb_32 (&BIH[8]);
		State->Header.depth = lsb_16 (&BIH[14]);
		State->Compressed = lsb_32 (&BIH[16]);
	} else if (State->Header.size == 64) {
                /* BMP OS/2 v2 */
288 289 290 291 292
		State->Header.width = lsb_32 (&BIH[4]);
		State->Header.height = lsb_32 (&BIH[8]);
		State->Header.depth = lsb_16 (&BIH[14]);
		State->Compressed = lsb_32 (&BIH[16]);
	} else if (State->Header.size == 40) {
293
                /* BMP v3 */ 
294 295 296 297
		State->Header.width = lsb_32 (&BIH[4]);
		State->Header.height = lsb_32 (&BIH[8]);
		State->Header.depth = lsb_16 (&BIH[14]);
		State->Compressed = lsb_32 (&BIH[16]);
298
	} else if (State->Header.size == 12) {
299
                /* BMP OS/2 */
300 301 302
		State->Header.width = lsb_16 (&BIH[4]);
		State->Header.height = lsb_16 (&BIH[6]);
		State->Header.depth = lsb_16 (&BIH[10]);
303
		State->Compressed = BI_RGB;
304 305 306 307 308
	} else {
		g_set_error (error,
			     GDK_PIXBUF_ERROR,
			     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
			     _("BMP image has unsupported header size"));
309
		State->read_state = READ_STATE_ERROR;
310 311
		return FALSE;
	}
312

313 314 315 316 317
	if (State->Header.size == 12)
		clrUsed = 1 << State->Header.depth;
	else
		clrUsed = (int) (BIH[35] << 24) + (BIH[34] << 16) + (BIH[33] << 8) + (BIH[32]);

318 319 320
	if (clrUsed != 0)
		State->Header.n_colors = clrUsed;
	else
321
            State->Header.n_colors = (1 << State->Header.depth);
322
	
323
	if (State->Header.n_colors > (1 << State->Header.depth)) {
324 325 326 327 328 329 330 331
		g_set_error (error,
			     GDK_PIXBUF_ERROR,
			     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
			     _("BMP image has bogus header data"));
		State->read_state = READ_STATE_ERROR;
		return FALSE;
	}

332
	State->Type = State->Header.depth;	/* This may be less trivial someday */
333

334
	/* Negative heights indicates bottom-down pixelorder */
335 336 337 338
	if (State->Header.height < 0) {
		State->Header.height = -State->Header.height;
		State->Header.Negative = 1;
	}
339 340 341 342 343 344 345 346 347 348

	if (State->Header.Negative && 
	    (State->Compressed != BI_RGB && State->Compressed != BI_BITFIELDS))
	{
		g_set_error (error,
			     GDK_PIXBUF_ERROR,
			     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
			     _("Topdown BMP images cannot be compressed"));
		State->read_state = READ_STATE_ERROR;
		return FALSE;
349
	}
350

351
	if (State->Header.width <= 0 || State->Header.height == 0 ||
352 353
	    (State->Compressed == BI_RLE4 && State->Type != 4)    ||
	    (State->Compressed == BI_RLE8 && State->Type != 8)	  ||
354
	    (State->Compressed == BI_BITFIELDS && !(State->Type == 16 || State->Type == 32)) ||
355
	    (State->Compressed > BI_BITFIELDS)) {
356 357 358 359
		g_set_error (error,
			     GDK_PIXBUF_ERROR,
			     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
			     _("BMP image has bogus header data"));
360
		State->read_state = READ_STATE_ERROR;
361 362 363
		return FALSE;
	}

364 365
	if (State->Type == 32)
		State->LineWidth = State->Header.width * 4;
366
	else if (State->Type == 24)
367
		State->LineWidth = State->Header.width * 3;
368 369 370
	else if (State->Type == 16)
		State->LineWidth = State->Header.width * 2;
	else if (State->Type == 8)
371
		State->LineWidth = State->Header.width * 1;
372
	else if (State->Type == 4)
373
		State->LineWidth = (State->Header.width + 1) / 2;
374
	else if (State->Type == 1) {
375 376 377
		State->LineWidth = State->Header.width / 8;
		if ((State->Header.width & 7) != 0)
			State->LineWidth++;
378 379 380 381 382
	} else {
		g_set_error (error,
			     GDK_PIXBUF_ERROR,
			     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
			     _("BMP image has bogus header data"));
383
		State->read_state = READ_STATE_ERROR;
384
		return FALSE;
385
	}
386

387
	/* Pad to a 32 bit boundary */
388 389
	if (((State->LineWidth % 4) > 0)
	    && (State->Compressed == BI_RGB || State->Compressed == BI_BITFIELDS))
390 391
		State->LineWidth = (State->LineWidth / 4) * 4 + 4;

392
	if (State->pixbuf == NULL) {
393 394 395 396 397 398 399 400 401 402 403 404
		if (State->size_func) {
			gint width = State->Header.width;
			gint height = State->Header.height;

			(*State->size_func) (&width, &height, State->user_data);
			if (width == 0 || height == 0) {
				State->read_state = READ_STATE_DONE;
				State->BufferSize = 0;
				return TRUE;
			}
		}

405 406 407
		if (State->Type == 32 || 
		    State->Compressed == BI_RLE4 || 
		    State->Compressed == BI_RLE8)
408
			State->pixbuf =
409 410 411
				gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
					       (gint) State->Header.width,
					       (gint) State->Header.height);
412 413
		else
			State->pixbuf =
414 415 416 417 418 419 420 421 422
				gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8,
					       (gint) State->Header.width,
					       (gint) State->Header.height);
		
		if (State->pixbuf == NULL) {
			g_set_error (error,
				     GDK_PIXBUF_ERROR,
				     GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
				     _("Not enough memory to load bitmap image"));
423
			State->read_state = READ_STATE_ERROR;
424 425 426
			return FALSE;
			}
		
427 428
		if (State->prepared_func != NULL)
			/* Notify the client that we are ready to go */
Havoc Pennington's avatar
Havoc Pennington committed
429
			(*State->prepared_func) (State->pixbuf, NULL, State->user_data);
430 431 432 433 434 435 436
		
		/* make all pixels initially transparent */
		if (State->Compressed == BI_RLE4 || State->Compressed == BI_RLE8) {
			memset (State->pixbuf->pixels, 0, State->pixbuf->rowstride * State->Header.height);
			State->compr.p = State->pixbuf->pixels 
				+ State->pixbuf->rowstride * (State->Header.height- 1);
		}
437
	}
438
	
439
	State->BufferDone = 0;
440
	if (State->Type <= 8) {
441 442
                gint samples;

443
		State->read_state = READ_STATE_PALETTE;
444 445 446 447 448 449 450 451 452 453

		/* Allocate enough to hold the palette */
	        samples = (State->Header.size == 12 ? 3 : 4);
		State->BufferSize = State->Header.n_colors * samples;

		/* Skip over everything between the palette and the data.
		   This protects us against a malicious BFH[10] value.
                */
		State->BufferPadding = (lsb_32 (&BFH[10]) - 14 - State->Header.size) - State->BufferSize;

454
	} else if (State->Compressed == BI_RGB) {
455 456 457 458 459 460 461 462 463 464 465 466
		if (State->BufferSize < lsb_32 (&BFH[10]))
		{
			/* skip over padding between headers and image data */
			State->read_state = READ_STATE_HEADERS;
			State->BufferDone = State->BufferSize;
			State->BufferSize = lsb_32 (&BFH[10]);
		}
		else
		{
			State->read_state = READ_STATE_DATA;
			State->BufferSize = State->LineWidth;
		}
467
	} else if (State->Compressed == BI_BITFIELDS) {
468 469 470 471 472 473 474 475 476 477 478 479 480
               if (State->Header.size == 108 || State->Header.size == 124) 
               {
			/* v4 and v5 have the bitmasks in the header */
			if (!decode_bitmasks (&BIH[40], State, error)) {
			       State->read_state = READ_STATE_ERROR;
			       return FALSE;
                        }
               }
               else 
               {
		       State->read_state = READ_STATE_BITMASKS;
		       State->BufferSize = 12;
               }
481 482 483 484 485 486 487 488
	} else {
		g_set_error (error,
			     GDK_PIXBUF_ERROR,
			     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
			     _("BMP image has bogus header data"));
		State->read_state = READ_STATE_ERROR;
		return FALSE;
	}
489

490 491
	if (!grow_buffer (State, error)) 
		return FALSE;
492 493 494 495

        return TRUE;
}

496 497 498
static gboolean DecodeColormap (guchar *buff,
				struct bmp_progressive_state *State,
				GError **error)
499 500
{
	gint i;
501
	gint samples;
502

503 504
	g_assert (State->read_state == READ_STATE_PALETTE);

505 506 507 508 509 510 511 512
	samples = (State->Header.size == 12 ? 3 : 4);
	if (State->BufferSize < State->Header.n_colors * samples) {
		State->BufferSize = State->Header.n_colors * samples;
		if (!grow_buffer (State, error))
			return FALSE;
		return TRUE;
	}

513
	State->Colormap = g_malloc0 ((1 << State->Header.depth) * sizeof (*State->Colormap));
514
	for (i = 0; i < State->Header.n_colors; i++)
515 516

	{
517 518 519
		State->Colormap[i][0] = buff[i * samples];
		State->Colormap[i][1] = buff[i * samples + 1];
		State->Colormap[i][2] = buff[i * samples + 2];
520 521 522 523 524 525
#ifdef DUMPCMAP
		g_print ("color %d %x %x %x\n", i,
			 State->Colormap[i][0],
			 State->Colormap[i][1],
			 State->Colormap[i][2]);
#endif
526 527
	}

528 529
	State->read_state = READ_STATE_DATA;

530
	State->BufferDone = 0;
531
	if (!(State->Compressed == BI_RGB || State->Compressed == BI_BITFIELDS))
532 533 534
		State->BufferSize = 2;
	else
		State->BufferSize = State->LineWidth;
535 536 537
	
	if (!grow_buffer (State, error))
		return FALSE;
538

539
	return TRUE;
540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
}

/* Finds the lowest set bit and the number of set bits */
static void
find_bits (int n, int *lowest, int *n_set)
{
	int i;

	*n_set = 0;

	for (i = 31; i >= 0; i--)
		if (n & (1 << i)) {
			*lowest = i;
			(*n_set)++;
		}
}

557
/* Decodes the bitmasks for BI_BITFIELDS coding */
558 559 560 561
static gboolean
decode_bitmasks (guchar *buf,
		 struct bmp_progressive_state *State, 
		 GError **error)
562
{
563
        State->a_mask = State->a_shift = State->a_bits = 0;
564 565 566 567 568 569 570 571 572 573 574 575
	State->r_mask = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
	buf += 4;

	State->g_mask = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
	buf += 4;

	State->b_mask = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);

	find_bits (State->r_mask, &State->r_shift, &State->r_bits);
	find_bits (State->g_mask, &State->g_shift, &State->g_bits);
	find_bits (State->b_mask, &State->b_shift, &State->b_bits);

576 577 578 579 580 581 582
        /* v4 and v5 have an alpha mask */
        if (State->Header.size == 108 || State->Header.size == 124) {
	      buf += 4;
	      State->a_mask = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
	      find_bits (State->a_mask, &State->a_shift, &State->a_bits);
        }

583
	if (State->r_bits == 0 || State->g_bits == 0 || State->b_bits == 0) {
584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
                if (State->Type == 16) {
		       State->r_mask = 0x7c00;
		       State->r_shift = 10;
		       State->g_mask = 0x03e0;
		       State->g_shift = 5;
		       State->b_mask = 0x001f;
		       State->b_shift = 0;

		       State->r_bits = State->g_bits = State->b_bits = 5;
                }
                else {
		       State->r_mask = 0x00ff0000;
		       State->r_shift = 16;
		       State->g_mask = 0x0000ff00;
		       State->g_shift = 8;
		       State->b_mask = 0x000000ff;
		       State->b_shift = 0;
		       State->a_mask = 0xff000000;
		       State->a_shift = 24;

		       State->r_bits = State->g_bits = State->b_bits = State->a_bits = 8;
                }
606 607 608 609 610
	}

	State->read_state = READ_STATE_DATA;
	State->BufferDone = 0;
	State->BufferSize = State->LineWidth;
611 612 613 614
	if (!grow_buffer (State, error)) 
		return FALSE;

	return TRUE;
615 616
}

617
/*
618 619 620 621 622
 * func - called when we have pixmap created (but no image data)
 * user_data - passed as arg 1 to func
 * return context (opaque to user)
 */

623
static gpointer
624 625 626
gdk_pixbuf__bmp_image_begin_load(GdkPixbufModuleSizeFunc size_func,
                                 GdkPixbufModulePreparedFunc prepared_func,
				 GdkPixbufModuleUpdatedFunc updated_func,
Havoc Pennington's avatar
Havoc Pennington committed
627
                                 gpointer user_data,
Havoc Pennington's avatar
Havoc Pennington committed
628
                                 GError **error)
629 630
{
	struct bmp_progressive_state *context;
631
	
632
	context = g_new0(struct bmp_progressive_state, 1);
633
	context->size_func = size_func;
634 635 636 637
	context->prepared_func = prepared_func;
	context->updated_func = updated_func;
	context->user_data = user_data;

638 639
	context->read_state = READ_STATE_HEADERS;

640
	context->BufferSize = 26;
641
	context->BufferPadding = 0;
642 643
	context->buff = g_malloc(26);
	context->BufferDone = 0;
644
	/* 14 for the BitmapFileHeader, 12 for the BitmapImageHeader */
645

646
	context->Colormap = NULL;
647 648 649 650 651 652

	context->Lines = 0;

	context->Type = 0;

	memset(&context->Header, 0, sizeof(struct headerpair));
653
	memset(&context->compr, 0, sizeof(struct bmp_compression_state));
654 655 656


	context->pixbuf = NULL;
657
	
658 659 660 661 662 663 664 665
	return (gpointer) context;
}

/*
 * context - returned from image_begin_load
 *
 * free context, unref gdk_pixbuf
 */
666
static gboolean gdk_pixbuf__bmp_image_stop_load(gpointer data, GError **error)
667 668 669 670
{
	struct bmp_progressive_state *context =
	    (struct bmp_progressive_state *) data;

671 672
        /* FIXME this thing needs to report errors if
         * we have unused image data
673
         */
674
	
675
	g_return_val_if_fail(context != NULL, TRUE);
676

677 678
	if (context->Colormap != NULL)
		g_free(context->Colormap);
679 680

	if (context->pixbuf)
681
		g_object_unref(context->pixbuf);
682

683
	g_free(context->buff);
684
	g_free(context);
685 686

        return TRUE;
687 688 689
}


690 691 692 693 694 695
/*
The OneLineXX functions are called when 1 line worth of data is present.
OneLine24 is the 24 bpp-version.
*/
static void OneLine32(struct bmp_progressive_state *context)
{
696
	int i;
697 698
	guchar *pixels;
	guchar *src;
699

700 701 702
	if (!context->Header.Negative)
		pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride * (context->Header.height - context->Lines - 1));
703
	else
704 705 706 707 708 709 710 711 712
		pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride * context->Lines);

	src = context->buff;

	if (context->Compressed == BI_BITFIELDS) {
		int r_lshift, r_rshift;
		int g_lshift, g_rshift;
		int b_lshift, b_rshift;
713
		int a_lshift, a_rshift;
714 715 716 717

		r_lshift = 8 - context->r_bits;
		g_lshift = 8 - context->g_bits;
		b_lshift = 8 - context->b_bits;
718
		a_lshift = 8 - context->a_bits;
719 720 721 722

		r_rshift = context->r_bits - r_lshift;
		g_rshift = context->g_bits - g_lshift;
		b_rshift = context->b_bits - b_lshift;
723
		a_rshift = context->a_bits - a_lshift;
724

725
		for (i = 0; i < context->Header.width; i++) {
726
			int v, r, g, b, a;
727

728
			v = src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
729 730 731 732

			r = (v & context->r_mask) >> context->r_shift;
			g = (v & context->g_mask) >> context->g_shift;
			b = (v & context->b_mask) >> context->b_shift;
733
			a = (v & context->a_mask) >> context->a_shift;
734 735 736 737

			*pixels++ = (r << r_lshift) | (r >> r_rshift);
			*pixels++ = (g << g_lshift) | (g >> g_rshift);
			*pixels++ = (b << b_lshift) | (b >> b_rshift);
738 739 740 741
                        if (context->a_bits)
			  *pixels++ = 0xff - (a << a_lshift) | (a >> a_rshift);
                        else
                          *pixels++ = 0xff;
742 743 744 745 746 747 748 749

			src += 4;
		}
	} else
		for (i = 0; i < context->Header.width; i++) {
			*pixels++ = src[2];
			*pixels++ = src[1];
			*pixels++ = src[0];
750
			*pixels++ = 0xff;
751 752 753

			src += 4;
		}
754 755
}

756 757 758 759 760 761
static void OneLine24(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
762
	if (context->Header.Negative == 0)
763 764 765
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
766
	else
767 768 769
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
770
	while (X < context->Header.width) {
771 772 773
		Pixels[X * 3 + 0] = context->buff[X * 3 + 2];
		Pixels[X * 3 + 1] = context->buff[X * 3 + 1];
		Pixels[X * 3 + 2] = context->buff[X * 3 + 0];
774 775 776 777 778
		X++;
	}

}

779 780
static void OneLine16(struct bmp_progressive_state *context)
{
781 782 783
	int i;
	guchar *pixels;
	guchar *src;
784

785 786 787
	if (!context->Header.Negative)
		pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride * (context->Header.height - context->Lines - 1));
788
	else
789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834
		pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride * context->Lines);

	src = context->buff;

	if (context->Compressed == BI_BITFIELDS) {
		int r_lshift, r_rshift;
		int g_lshift, g_rshift;
		int b_lshift, b_rshift;

		r_lshift = 8 - context->r_bits;
		g_lshift = 8 - context->g_bits;
		b_lshift = 8 - context->b_bits;

		r_rshift = context->r_bits - r_lshift;
		g_rshift = context->g_bits - g_lshift;
		b_rshift = context->b_bits - b_lshift;

		for (i = 0; i < context->Header.width; i++) {
			int v, r, g, b;

			v = (int) src[0] | ((int) src[1] << 8);

			r = (v & context->r_mask) >> context->r_shift;
			g = (v & context->g_mask) >> context->g_shift;
			b = (v & context->b_mask) >> context->b_shift;

			*pixels++ = (r << r_lshift) | (r >> r_rshift);
			*pixels++ = (g << g_lshift) | (g >> g_rshift);
			*pixels++ = (b << b_lshift) | (b >> b_rshift);

			src += 2;
		}
	} else
		for (i = 0; i < context->Header.width; i++) {
			int v, r, g, b;

			v = src[0] | (src[1] << 8);

			r = (v >> 10) & 0x1f;
			g = (v >> 5) & 0x1f;
			b = v & 0x1f;

			*pixels++ = (r << 3) | (r >> 2);
			*pixels++ = (g << 3) | (g >> 2);
			*pixels++ = (b << 3) | (b >> 2);
835 836

			src += 2;
837
		}
838 839
}

840 841 842 843 844 845
static void OneLine8(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
846
	if (context->Header.Negative == 0)
847 848 849
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
850
	else
851 852 853
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
854 855
	while (X < context->Header.width) {
		Pixels[X * 3 + 0] =
856
		    context->Colormap[context->buff[X]][2];
857
		Pixels[X * 3 + 1] =
858
		    context->Colormap[context->buff[X]][1];
859
		Pixels[X * 3 + 2] =
860
		    context->Colormap[context->buff[X]][0];
861 862 863 864
		X++;
	}
}

865 866 867 868 869 870 871
static void OneLine4(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
872 873 874
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
875
	else
876 877 878
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
879 880 881 882

	while (X < context->Header.width) {
		guchar Pix;

883
		Pix = context->buff[X / 2];
884 885

		Pixels[X * 3 + 0] =
886
		    context->Colormap[Pix >> 4][2];
887
		Pixels[X * 3 + 1] =
888
		    context->Colormap[Pix >> 4][1];
889
		Pixels[X * 3 + 2] =
890
		    context->Colormap[Pix >> 4][0];
891 892 893 894
		X++;
		if (X < context->Header.width) {
			/* Handle the other 4 bit pixel only when there is one */
			Pixels[X * 3 + 0] =
895
			    context->Colormap[Pix & 15][2];
896
			Pixels[X * 3 + 1] =
897
			    context->Colormap[Pix & 15][1];
898
			Pixels[X * 3 + 2] =
899
			    context->Colormap[Pix & 15][0];
900 901 902 903 904 905
			X++;
		}
	}

}

906 907 908 909 910 911
static void OneLine1(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
912
	if (context->Header.Negative == 0)