io-bmp.c 20.3 KB
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/* GdkPixbuf library - Windows Bitmap image loader
 *
 * Copyright (C) 1999 The Free Software Foundation
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 *
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 * Authors: Arjan van de Ven <arjan@fenrus.demon.nl>
 *          Federico Mena-Quintero <federico@gimp.org>
 *
 * Based on io-ras.c
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 *
 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * 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
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
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 */

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/*

Known bugs:
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	* 4bpp compressed files don't work
	* bi-tonal files aren't tested with palettes
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*/

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#include <config.h>
#include <stdio.h>
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#include <string.h>
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#include "gdk-pixbuf-private.h"
#include "gdk-pixbuf-io.h"
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/* 

These structures are actually dummies. These are according to
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the "Windows API reference guide volume II" as written by 
Borland International, but GCC fiddles with the alignment of 
the internal members, so these aren't actually usable.
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*/

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struct BitmapFileHeader {
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	gushort bfType;
	guint bfSize;
	guint reserverd;
	guint bfOffbits;
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};

struct BitmapInfoHeader {
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	guint biSize;
	guint biWidth;
	guint biHeight;
	gushort biPlanes;
	gushort biBitCount;
	guint biCompression;
	guint biSizeImage;
	guint biXPelsPerMeter;
	guint biYPelsPerMeter;
	guint biClrUsed;
	guint biClrImportant;
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};

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/* 

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

*/
#if DUMPBIH
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static void DumpBIH(unsigned char *BIH)
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{
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	printf("biSize      = %i \n",
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	       (int) (BIH[3] << 24) + (BIH[2] << 16) + (BIH[1] << 8) +
	       (BIH[0]));
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	printf("biWidth     = %i \n",
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	       (int) (BIH[7] << 24) + (BIH[6] << 16) + (BIH[5] << 8) +
	       (BIH[4]));
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	printf("biHeight    = %i \n",
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	       (int) (BIH[11] << 24) + (BIH[10] << 16) + (BIH[9] << 8) +
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	       (BIH[8]));
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	printf("biPlanes    = %i \n", (int) (BIH[13] << 8) + (BIH[12]));
	printf("biBitCount  = %i \n", (int) (BIH[15] << 8) + (BIH[14]));
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	printf("biCompress  = %i \n",
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	       (int) (BIH[19] << 24) + (BIH[18] << 16) + (BIH[17] << 8) +
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	       (BIH[16]));
	printf("biSizeImage = %i \n",
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	       (int) (BIH[23] << 24) + (BIH[22] << 16) + (BIH[21] << 8) +
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	       (BIH[20]));
	printf("biXPels     = %i \n",
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	       (int) (BIH[27] << 24) + (BIH[26] << 16) + (BIH[25] << 8) +
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	       (BIH[24]));
	printf("biYPels     = %i \n",
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	       (int) (BIH[31] << 24) + (BIH[30] << 16) + (BIH[29] << 8) +
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	       (BIH[28]));
	printf("biClrUsed   = %i \n",
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	       (int) (BIH[35] << 24) + (BIH[34] << 16) + (BIH[33] << 8) +
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	       (BIH[32]));
	printf("biClrImprtnt= %i \n",
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	       (int) (BIH[39] << 24) + (BIH[38] << 16) + (BIH[37] << 8) +
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	       (BIH[36]));
}
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#endif
/* struct headerpair contains the decoded width/height/depth info for
   the current bitmap */
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struct headerpair {
	guint width;
	guint height;
	guint depth;
	guint Negative;		/* Negative = 1 -> top down BMP,  
				   Negative = 0 -> bottom up BMP */
};
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/* Data needed for the "state" during decompression */
struct bmp_compression_state {
	gint phase;		/* 0 = clean, 
				   1 = count received
				   2 = escape received
				   3 = in "raw" run
				   4 = Relative part 1 is next
				   5 = Relative part 2 is next
				   6 = end of image -> No more input allowed
				 */
	gint RunCount;
	gint XDelta;
	gint YDelta;
};
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/* Progressive loading */

struct bmp_progressive_state {
	ModulePreparedNotifyFunc prepared_func;
	ModuleUpdatedNotifyFunc updated_func;
	gpointer user_data;

	gint HeaderSize;	/* The size of the header-part (incl colormap) */
	guchar *HeaderBuf;	/* The buffer for the header (incl colormap) */
	gint HeaderDone;	/* The nr of bytes actually in HeaderBuf */

	gint LineWidth;		/* The width of a line in bytes */
	guchar *LineBuf;	/* Buffer for 1 line */
	gint LineDone;		/* # of bytes in LineBuf */
	gint Lines;		/* # of finished lines */

	gint Type;		/*  
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				   32 = RGB + alpha
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				   24 = RGB
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				   4  = 4 bpp colormapped
				   8  = 8 bpp colormapped
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				   1  = 1 bit bitonal 
				 */
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	gint Compressed;
	struct bmp_compression_state compr;
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	struct headerpair Header;	/* Decoded (BE->CPU) header */


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

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static gpointer
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gdk_pixbuf__bmp_image_begin_load(ModulePreparedNotifyFunc prepared_func,
				 ModuleUpdatedNotifyFunc updated_func,
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                                 gpointer user_data,
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                                 GError **error);
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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);
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/* Shared library entry point --> This should be removed when
   generic_image_load enters gdk-pixbuf-io. */
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static GdkPixbuf *gdk_pixbuf__bmp_image_load(FILE * f, GError **error)
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{
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	guchar membuf[4096];
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	size_t length;
	struct bmp_progressive_state *State;
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	GdkPixbuf *pb;
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	State =
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	    gdk_pixbuf__bmp_image_begin_load(NULL, NULL, NULL,
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                                             error);
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        if (State == NULL)
          return NULL;
        
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	while (feof(f) == 0) {
		length = fread(membuf, 1, 4096, f);
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		if (length > 0)
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                  if (!gdk_pixbuf__bmp_image_load_increment(State,
                                                            membuf,
                                                            length,
                                                            error)) {
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                          gdk_pixbuf__bmp_image_stop_load (State, NULL);
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                          return NULL;
                  }
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	}
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	if (State->pixbuf != NULL)
		gdk_pixbuf_ref(State->pixbuf);

	pb = State->pixbuf;

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	gdk_pixbuf__bmp_image_stop_load(State, NULL);
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	return pb;
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}

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static gboolean DecodeHeader(unsigned char *BFH, unsigned char *BIH,
                             struct bmp_progressive_state *State,
                             GError **error)
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{
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        gboolean retval = TRUE;

        /* FIXME this is totally unrobust against bogus image data. */
        
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#if DUMPBIH
	DumpBIH(BIH);
#endif

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	State->Header.width =
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	    (int) (BIH[7] << 24) + (BIH[6] << 16) + (BIH[5] << 8) +
	    (BIH[4]);
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	State->Header.height =
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	    (int) (BIH[11] << 24) + (BIH[10] << 16) + (BIH[9] << 8) +
	    (BIH[8]);
	State->Header.depth = (int) (BIH[15] << 8) + (BIH[14]);;
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	State->Type = State->Header.depth;	/* This may be less trivial someday */
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	State->HeaderSize =
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	    (int) ((BFH[13] << 24) + (BFH[12] << 16) + (BFH[11] << 8) +
		   (BFH[10]));
	if (State->HeaderSize >= 14 + 40 + 1024)
		State->HeaderBuf =
		    g_realloc(State->HeaderBuf, State->HeaderSize);
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	if ((BIH[16] != 0) || (BIH[17] != 0) || (BIH[18] != 0)
	    || (BIH[19] != 0)) {
		State->Compressed = 1;
	}

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	/* Negative heights indicates bottom-down pixelorder */
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	if (State->Header.height < 0) {
		State->Header.height = -State->Header.height;
		State->Header.Negative = 1;
	}
	if (State->Header.width < 0) {
		State->Header.width = -State->Header.width;
		State->Header.Negative = 0;
	}
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	if (State->Type == 32)
		State->LineWidth = State->Header.width * 4;
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	if (State->Type == 24)
		State->LineWidth = State->Header.width * 3;
	if (State->Type == 8)
		State->LineWidth = State->Header.width * 1;
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	if (State->Type == 4)
		State->LineWidth = (State->Header.width + 1) / 2;
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	if (State->Type == 1) {
		State->LineWidth = State->Header.width / 8;
		if ((State->Header.width & 7) != 0)
			State->LineWidth++;
	}
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	/* Pad to a 32 bit boundary */
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	if (((State->LineWidth % 4) > 0) && (State->Compressed == 0))
		State->LineWidth = (State->LineWidth / 4) * 4 + 4;

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	if (State->LineBuf == NULL)
		State->LineBuf = g_malloc(State->LineWidth);

	if (State->pixbuf == NULL) {
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		if (State->Type == 32)
			State->pixbuf =
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			    gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
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					   (gint) State->Header.width,
					   (gint) State->Header.height);
		else
			State->pixbuf =
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			    gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8,
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					   (gint) State->Header.width,
					   (gint) State->Header.height);
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                if (State->pixbuf == NULL) {
                        g_set_error (error,
                                     GDK_PIXBUF_ERROR,
                                     GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
                                     _("Not enough memory to load bitmap image"));
                        retval = FALSE;
                }
                
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		if (State->prepared_func != NULL)
			/* Notify the client that we are ready to go */
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			(*State->prepared_func) (State->pixbuf, NULL, State->user_data);
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	}
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        return retval;
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}

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

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static gpointer
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gdk_pixbuf__bmp_image_begin_load(ModulePreparedNotifyFunc prepared_func,
				 ModuleUpdatedNotifyFunc updated_func,
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                                 gpointer user_data,
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                                 GError **error)
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{
	struct bmp_progressive_state *context;

	context = g_new0(struct bmp_progressive_state, 1);
	context->prepared_func = prepared_func;
	context->updated_func = updated_func;
	context->user_data = user_data;

	context->HeaderSize = 54;
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	context->HeaderBuf = g_malloc(14 + 40 + 1024);
	/* 14 for the BitmapFileHeader, 40 for the BitmapImageHeader and 
	   1024 for the colormap */

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	context->HeaderDone = 0;

	context->LineWidth = 0;
	context->LineBuf = NULL;
	context->LineDone = 0;
	context->Lines = 0;

	context->Type = 0;

	memset(&context->Header, 0, sizeof(struct headerpair));
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	memset(&context->compr, 0, sizeof(struct bmp_compression_state));
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	context->pixbuf = NULL;


	return (gpointer) context;
}

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

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        /* FIXME this thing needs to report errors if
         * we have unused image data
         */        
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	g_return_val_if_fail(context != NULL, TRUE);
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	if (context->LineBuf != NULL)
		g_free(context->LineBuf);
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	context->LineBuf = NULL;
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	if (context->HeaderBuf != NULL)
		g_free(context->HeaderBuf);
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	context->LineBuf = NULL;
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	if (context->pixbuf)
		gdk_pixbuf_unref(context->pixbuf);

	g_free(context);
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        return TRUE;
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}


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/*
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)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
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	else
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
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	while (X < context->Header.width) {
		Pixels[X * 4 + 0] = context->LineBuf[X * 4 + 2];
		Pixels[X * 4 + 1] = context->LineBuf[X * 4 + 1];
		Pixels[X * 4 + 2] = context->LineBuf[X * 4 + 0];
		Pixels[X * 4 + 3] = context->LineBuf[X * 4 + 3];
		X++;
	}

}

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static void OneLine24(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
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	if (context->Header.Negative == 0)
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
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	else
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
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	while (X < context->Header.width) {
		Pixels[X * 3 + 0] = context->LineBuf[X * 3 + 2];
		Pixels[X * 3 + 1] = context->LineBuf[X * 3 + 1];
		Pixels[X * 3 + 2] = context->LineBuf[X * 3 + 0];
		X++;
	}

}

static void OneLine8(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
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	if (context->Header.Negative == 0)
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
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	else
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
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	while (X < context->Header.width) {
		Pixels[X * 3 + 0] =
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		    context->HeaderBuf[4 * context->LineBuf[X] + 56];
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		Pixels[X * 3 + 1] =
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		    context->HeaderBuf[4 * context->LineBuf[X] + 55];
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		Pixels[X * 3 + 2] =
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		    context->HeaderBuf[4 * context->LineBuf[X] + 54];
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		X++;
	}
}

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static void OneLine4(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
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	else
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
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	while (X < context->Header.width) {
		guchar Pix;

		Pix = context->LineBuf[X / 2];

		Pixels[X * 3 + 0] =
		    context->HeaderBuf[4 * (Pix >> 4) + 56];
		Pixels[X * 3 + 1] =
		    context->HeaderBuf[4 * (Pix >> 4) + 55];
		Pixels[X * 3 + 2] =
		    context->HeaderBuf[4 * (Pix >> 4) + 54];
		X++;
		if (X < context->Header.width) {
			/* Handle the other 4 bit pixel only when there is one */
			Pixels[X * 3 + 0] =
			    context->HeaderBuf[4 * (Pix & 15) + 56];
			Pixels[X * 3 + 1] =
			    context->HeaderBuf[4 * (Pix & 15) + 55];
			Pixels[X * 3 + 2] =
			    context->HeaderBuf[4 * (Pix & 15) + 54];
			X++;
		}
	}

}

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static void OneLine1(struct bmp_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
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	if (context->Header.Negative == 0)
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
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	else
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		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
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	while (X < context->Header.width) {
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		gint Bit;
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		Bit = (context->LineBuf[X / 8]) >> (7 - (X & 7));
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		Bit = Bit & 1;
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		Pixels[X * 3 + 0] = Bit * 255;
		Pixels[X * 3 + 1] = Bit * 255;
		Pixels[X * 3 + 2] = Bit * 255;
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		X++;
	}
}


static void OneLine(struct bmp_progressive_state *context)
{
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	context->LineDone = 0;
	if (context->Lines >= context->Header.height)
		return;

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	if (context->Type == 32)
		OneLine32(context);
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	if (context->Type == 24)
		OneLine24(context);
	if (context->Type == 8)
		OneLine8(context);
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	if (context->Type == 4)
		OneLine4(context);
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	if (context->Type == 1)
		OneLine1(context);

	context->Lines++;

	if (context->updated_func != NULL) {
		(*context->updated_func) (context->pixbuf,
					  0,
					  context->Lines,
					  context->Header.width,
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					  context->Header.height,
					  context->user_data);
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	}
}

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/* DoCompressedByte handles 1 byte of incomming compressed data */
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static void
DoCompressedByte(struct bmp_progressive_state *context, guchar ** buf,
                 gint * size)
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{
	gint BytesToCopy;
	switch (context->compr.phase) {
	case 0:		/* Neutral state */
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		if ((*buf)[0] != 0) {	/* run count */
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			context->compr.phase = 1;
			context->compr.RunCount = (*buf)[0];
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		} else {	/* Escape */
			context->compr.phase = 2;
		}
		(*buf)++;
		(*size)--;
		break;
	case 1:		/* Run count received.... */
		while (context->compr.RunCount > 0) {
			BytesToCopy =
			    context->LineWidth - context->LineDone;
			if (BytesToCopy > context->compr.RunCount)
				BytesToCopy = context->compr.RunCount;
			if (BytesToCopy > 0) {
				memset(context->LineBuf +
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				       context->LineDone, (*buf)[0],
				       BytesToCopy);
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				context->compr.RunCount -= BytesToCopy;
				context->LineDone += BytesToCopy;
			}
			if ((context->LineDone >= context->LineWidth)
			    && (context->LineWidth > 0)) {
				OneLine(context);
			}
		}
		context->compr.phase = 0;
		(*buf)++;
		(*size)--;
		break;
	case 2:		/* Escape received */
		if ((*buf)[0] == 0) {	/* End of line */
			context->compr.phase = 0;
			if (context->LineDone > 0)
				OneLine(context);
		} else if ((*buf)[0] == 1) {	/* End of image */
			OneLine(context);
			context->compr.phase = 6;
			(*size) = 0;
			break;
		} else if ((*buf)[0] == 2) {	/* Cursor displacement */
			context->compr.phase = 4;
		} else {
			context->compr.phase = 3;
			context->compr.RunCount = (*buf)[0];
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			if (context->compr.RunCount & 1)
				context->compr.phase = 7;

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		}
		(*buf)++;
		(*size)--;

		break;
	case 3:
		while ((context->compr.RunCount > 0)
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		       && (*size > 0)) {
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			BytesToCopy =
			    context->LineWidth - context->LineDone;
			if (BytesToCopy > context->compr.RunCount)
				BytesToCopy = context->compr.RunCount;
			if (BytesToCopy > *size)
				BytesToCopy = *size;

			if (BytesToCopy > 0) {
				memcpy(context->LineBuf +
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				       context->LineDone, *buf,
				       BytesToCopy);
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				context->compr.RunCount -= BytesToCopy;
				(*buf) += BytesToCopy;
				(*size) -= BytesToCopy;
				context->LineDone += BytesToCopy;
			}
			if ((context->LineDone >= context->LineWidth)
			    && (context->LineWidth > 0))
				OneLine(context);
		}
		if (context->compr.RunCount <= 0)
			context->compr.phase = 0;

		break;
	case 4:
		context->compr.phase = 5;
		context->compr.XDelta = (*buf)[0];
		(*buf)++;
		(*size)--;
		break;
	case 5:
		context->compr.phase = 0;
		context->compr.YDelta = (*buf)[0];
		g_assert(0);	/* No implementatio of this yet */
		/* If this happens, please email me (arjan@fenrus.demon.nl)
		   the image concerned. */
		(*buf)++;
		(*size)--;
		break;
	case 6:
		(*size) = 0;
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		break;
	case 7:		/* Odd raw run */
		while ((context->compr.RunCount > 0) && (*size > 0)) {
			BytesToCopy =
			    context->LineWidth - context->LineDone;
			if (BytesToCopy > context->compr.RunCount)
				BytesToCopy = context->compr.RunCount;
			if (BytesToCopy > *size)
				BytesToCopy = *size;

			if (BytesToCopy > 0) {
				memcpy(context->LineBuf +
				       context->LineDone, *buf,
				       BytesToCopy);

				context->compr.RunCount -= BytesToCopy;
				(*buf) += BytesToCopy;
				(*size) -= BytesToCopy;
				context->LineDone += BytesToCopy;
			}
			if ((context->LineDone >= context->LineWidth)
			    && (context->LineWidth > 0))
				OneLine(context);
		}
		if (context->compr.RunCount <= 0)
			context->compr.phase = 8;

		break;
	case 8:		/* Eat dummy byte; */
		(*buf)++;
		(*size)--;
		context->compr.phase = 0;
		break;
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	}
}

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/*
 * context - from image_begin_load
 * buf - new image data
 * size - length of new image data
 *
 * append image data onto inrecrementally built output image
 */
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static gboolean
gdk_pixbuf__bmp_image_load_increment(gpointer data,
                                     const guchar * buf,
                                     guint size,
                                     GError **error)
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{
	struct bmp_progressive_state *context =
	    (struct bmp_progressive_state *) data;

	gint BytesToCopy;

	while (size > 0) {
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		g_assert(context->LineDone >= 0);
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		if (context->HeaderDone < context->HeaderSize) {	/* We still 
									   have headerbytes to do */
			BytesToCopy =
			    context->HeaderSize - context->HeaderDone;
			if (BytesToCopy > size)
				BytesToCopy = size;

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			memmove(context->HeaderBuf + context->HeaderDone,
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				buf, BytesToCopy);
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			size -= BytesToCopy;
			buf += BytesToCopy;
			context->HeaderDone += BytesToCopy;

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		} else if (context->Compressed) {
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			/* Compression is done 1 byte at a time for now */
			DoCompressedByte(context, &buf, &size);
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		} else {
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			/* Uncompressed pixeldata */
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			BytesToCopy =
			    context->LineWidth - context->LineDone;
			if (BytesToCopy > size)
				BytesToCopy = size;

			if (BytesToCopy > 0) {
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				memmove(context->LineBuf +
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					context->LineDone, buf,
					BytesToCopy);
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				size -= BytesToCopy;
				buf += BytesToCopy;
				context->LineDone += BytesToCopy;
			}
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			if ((context->LineDone >= context->LineWidth)
			    && (context->LineWidth > 0))
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				OneLine(context);


		}

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		if (context->HeaderDone >= 14 + 40)
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                        if (!DecodeHeader(context->HeaderBuf,
                                          context->HeaderBuf + 14, context,
                                          error))
                                return FALSE;
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	}
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	return TRUE;
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}
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void
gdk_pixbuf__bmp_fill_vtable (GdkPixbufModule *module)
{
  module->load = gdk_pixbuf__bmp_image_load;
  module->begin_load = gdk_pixbuf__bmp_image_begin_load;
  module->stop_load = gdk_pixbuf__bmp_image_stop_load;
  module->load_increment = gdk_pixbuf__bmp_image_load_increment;
}