gtk2/gdk-pixbuf/io-bmp.c
Matthias Clasen 94218b8cfe New function for loading an image from a file either via module->load or
* gdk-pixbuf-io.c (generic_image_load): New function for loading
	an image from a file either via module->load or incrementally.
	(prepared_notify): ModulePreparedNotifyFunc for generic_image_load.
	(gdk_pixbuf_new_from_file): Use generic_image_load.
	* io-bmp.c, io-ico.c, io-ras.c, io-wbmp.c: Remove trivial
	implementations of module->load.  (#71266)
2002-07-07 20:29:48 +00:00

1051 lines
27 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* GdkPixbuf library - Windows Bitmap image loader
*
* Copyright (C) 1999 The Free Software Foundation
*
* Authors: Arjan van de Ven <arjan@fenrus.demon.nl>
* Federico Mena-Quintero <federico@gimp.org>
*
* Based on io-ras.c
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <config.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include "gdk-pixbuf-private.h"
#include "gdk-pixbuf-io.h"
#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.
*/
struct BitmapFileHeader {
guint16 magic;
guint32 file_size;
guint32 reserved;
guint32 data_offset;
};
struct BitmapInfoHeader {
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;
};
#endif
/* Compression values */
#define BI_RGB 0
#define BI_RLE8 1
#define BI_RLE4 2
#define BI_BITFIELDS 3
/* 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;
/*
DumpBIH printf's the values in a BitmapInfoHeader to the screen, for
debugging purposes.
*/
#if DUMPBIH
static void DumpBIH(unsigned char *BIH)
{
printf("biSize = %i \n",
(int) (BIH[3] << 24) + (BIH[2] << 16) + (BIH[1] << 8) +
(BIH[0]));
printf("biWidth = %i \n",
(int) (BIH[7] << 24) + (BIH[6] << 16) + (BIH[5] << 8) +
(BIH[4]));
printf("biHeight = %i \n",
(int) (BIH[11] << 24) + (BIH[10] << 16) + (BIH[9] << 8) +
(BIH[8]));
printf("biPlanes = %i \n", (int) (BIH[13] << 8) + (BIH[12]));
printf("biBitCount = %i \n", (int) (BIH[15] << 8) + (BIH[14]));
printf("biCompress = %i \n",
(int) (BIH[19] << 24) + (BIH[18] << 16) + (BIH[17] << 8) +
(BIH[16]));
printf("biSizeImage = %i \n",
(int) (BIH[23] << 24) + (BIH[22] << 16) + (BIH[21] << 8) +
(BIH[20]));
printf("biXPels = %i \n",
(int) (BIH[27] << 24) + (BIH[26] << 16) + (BIH[25] << 8) +
(BIH[24]));
printf("biYPels = %i \n",
(int) (BIH[31] << 24) + (BIH[30] << 16) + (BIH[29] << 8) +
(BIH[28]));
printf("biClrUsed = %i \n",
(int) (BIH[35] << 24) + (BIH[34] << 16) + (BIH[33] << 8) +
(BIH[32]));
printf("biClrImprtnt= %i \n",
(int) (BIH[39] << 24) + (BIH[38] << 16) + (BIH[37] << 8) +
(BIH[36]));
}
#endif
/* struct headerpair contains the decoded width/height/depth info for
the current bitmap */
struct headerpair {
guint32 size;
gint32 width;
gint32 height;
guint depth;
guint Negative; /* Negative = 1 -> top down BMP,
Negative = 0 -> bottom up BMP */
};
/* Data needed for the "state" during decompression */
struct bmp_compression_state {
gint phase;
gint run;
gint count;
gint x, y;
guchar *p;
};
/* Progressive loading */
struct bmp_progressive_state {
ModulePreparedNotifyFunc prepared_func;
ModuleUpdatedNotifyFunc updated_func;
gpointer user_data;
ReadState read_state;
guint LineWidth;
guint Lines; /* # of finished lines */
guchar *buff;
gint BufferSize;
gint BufferDone;
guchar (*Colormap)[3];
gint Type; /*
32 = RGB + alpha
24 = RGB
16 = RGB
4 = 4 bpp colormapped
8 = 8 bpp colormapped
1 = 1 bit bitonal
*/
guint Compressed;
struct bmp_compression_state compr;
struct headerpair Header; /* Decoded (BE->CPU) header */
/* 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;
GdkPixbuf *pixbuf; /* Our "target" */
};
static gpointer
gdk_pixbuf__bmp_image_begin_load(ModuleSizeFunc size_func,
ModulePreparedNotifyFunc prepared_func,
ModuleUpdatedNotifyFunc updated_func,
gpointer user_data,
GError **error);
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);
/* 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);
}
static gboolean grow_buffer (struct bmp_progressive_state *State,
GError **error)
{
State->buff = g_try_realloc (State->buff, State->BufferSize);
if (State->buff == NULL) {
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;
}
return TRUE;
}
static gboolean DecodeHeader(unsigned char *BFH, unsigned char *BIH,
struct bmp_progressive_state *State,
GError **error)
{
/* FIXME this is totally unrobust against bogus image data. */
if (State->BufferSize < lsb_32 (&BIH[0]) + 14) {
State->BufferSize = lsb_32 (&BIH[0]) + 14;
if (!grow_buffer (State, error))
return FALSE;
return TRUE;
}
#if DUMPBIH
DumpBIH(BIH);
#endif
State->Header.size = lsb_32 (&BIH[0]);
if (State->Header.size == 40) {
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 == 12) {
State->Header.width = lsb_16 (&BIH[4]);
State->Header.height = lsb_16 (&BIH[6]);
State->Header.depth = lsb_16 (&BIH[10]);
State->Compressed = BI_RGB;
} else {
g_set_error (error,
GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
_("BMP image has unsupported header size"));
State->read_state = READ_STATE_ERROR;
return FALSE;
}
State->Type = State->Header.depth; /* This may be less trivial someday */
/* Negative heights indicates bottom-down pixelorder */
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;
}
if (State->Header.width == 0 || State->Header.height == 0 ||
(State->Compressed == BI_RLE4 && State->Type != 4) ||
(State->Compressed == BI_RLE8 && State->Type != 8) ||
(State->Compressed == BI_BITFIELDS && !(State->Type == 16 || State->Type == 32)) ||
State->Compressed > BI_BITFIELDS) {
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;
}
if (State->Type == 32)
State->LineWidth = State->Header.width * 4;
else if (State->Type == 24)
State->LineWidth = State->Header.width * 3;
else if (State->Type == 16)
State->LineWidth = State->Header.width * 2;
else if (State->Type == 8)
State->LineWidth = State->Header.width * 1;
else if (State->Type == 4)
State->LineWidth = (State->Header.width + 1) / 2;
else if (State->Type == 1) {
State->LineWidth = State->Header.width / 8;
if ((State->Header.width & 7) != 0)
State->LineWidth++;
} 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;
}
/* Pad to a 32 bit boundary */
if (((State->LineWidth % 4) > 0)
&& (State->Compressed == BI_RGB || State->Compressed == BI_BITFIELDS))
State->LineWidth = (State->LineWidth / 4) * 4 + 4;
if (State->pixbuf == NULL) {
if (State->Type == 32 ||
State->Compressed == BI_RLE4 ||
State->Compressed == BI_RLE8)
State->pixbuf =
gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
(gint) State->Header.width,
(gint) State->Header.height);
else
State->pixbuf =
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"));
State->read_state = READ_STATE_ERROR;
return FALSE;
}
if (State->prepared_func != NULL)
/* Notify the client that we are ready to go */
(*State->prepared_func) (State->pixbuf, NULL, State->user_data);
}
/* 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);
}
State->BufferDone = 0;
if (State->Type <= 8) {
State->read_state = READ_STATE_PALETTE;
State->BufferSize = lsb_32 (&BFH[10]) - 14 - State->Header.size;
} else if (State->Compressed == BI_RGB) {
State->read_state = READ_STATE_DATA;
State->BufferSize = State->LineWidth;
} else if (State->Compressed == BI_BITFIELDS) {
State->read_state = READ_STATE_BITMASKS;
State->BufferSize = 12;
} 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;
}
if (!grow_buffer (State, error))
return FALSE;
return TRUE;
}
static gboolean DecodeColormap (guchar *buff,
struct bmp_progressive_state *State,
GError **error)
{
gint i;
g_assert (State->read_state == READ_STATE_PALETTE);
State->Colormap = g_malloc ((1 << State->Header.depth) * sizeof (*State->Colormap));
for (i = 0; i < (1 << State->Header.depth); i++)
{
State->Colormap[i][0] = buff[i * (State->Header.size == 12 ? 3 : 4)];
State->Colormap[i][1] = buff[i * (State->Header.size == 12 ? 3 : 4) + 1];
State->Colormap[i][2] = buff[i * (State->Header.size == 12 ? 3 : 4) + 2];
#ifdef DUMPCMAP
g_print ("color %d %x %x %x\n", i,
State->Colormap[i][0],
State->Colormap[i][1],
State->Colormap[i][2]);
#endif
}
State->read_state = READ_STATE_DATA;
State->BufferDone = 0;
if (!(State->Compressed == BI_RGB || State->Compressed == BI_BITFIELDS))
State->BufferSize = 2;
else
State->BufferSize = State->LineWidth;
if (!grow_buffer (State, error))
return FALSE;
return TRUE;
}
/* 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)++;
}
}
/* Decodes the 3 shorts that follow for the bitmasks for BI_BITFIELDS coding */
static gboolean
decode_bitmasks (guchar *buf,
struct bmp_progressive_state *State,
GError **error)
{
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);
if (State->r_bits == 0 || State->g_bits == 0 || State->b_bits == 0) {
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;
}
State->read_state = READ_STATE_DATA;
State->BufferDone = 0;
State->BufferSize = State->LineWidth;
if (!grow_buffer (State, error))
return FALSE;
return TRUE;
}
/*
* func - called when we have pixmap created (but no image data)
* user_data - passed as arg 1 to func
* return context (opaque to user)
*/
static gpointer
gdk_pixbuf__bmp_image_begin_load(ModuleSizeFunc size_func,
ModulePreparedNotifyFunc prepared_func,
ModuleUpdatedNotifyFunc updated_func,
gpointer user_data,
GError **error)
{
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->read_state = READ_STATE_HEADERS;
context->BufferSize = 26;
context->buff = g_malloc(26);
context->BufferDone = 0;
/* 14 for the BitmapFileHeader, 12 for the BitmapImageHeader */
context->Colormap = NULL;
context->Lines = 0;
context->Type = 0;
memset(&context->Header, 0, sizeof(struct headerpair));
memset(&context->compr, 0, sizeof(struct bmp_compression_state));
context->pixbuf = NULL;
return (gpointer) context;
}
/*
* context - returned from image_begin_load
*
* free context, unref gdk_pixbuf
*/
static gboolean gdk_pixbuf__bmp_image_stop_load(gpointer data, GError **error)
{
struct bmp_progressive_state *context =
(struct bmp_progressive_state *) data;
/* FIXME this thing needs to report errors if
* we have unused image data
*/
g_return_val_if_fail(context != NULL, TRUE);
if (context->Colormap != NULL)
g_free(context->Colormap);
if (context->pixbuf)
g_object_unref(context->pixbuf);
g_free(context->buff);
g_free(context);
return TRUE;
}
/*
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)
{
int i;
guchar *pixels;
guchar *src;
if (!context->Header.Negative)
pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride * (context->Header.height - context->Lines - 1));
else
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 = src[0] | (src[1] << 8) | (src[2] << 16);
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);
*pixels++ = src[3]; /* alpha */
src += 4;
}
} else
for (i = 0; i < context->Header.width; i++) {
*pixels++ = src[2];
*pixels++ = src[1];
*pixels++ = src[0];
*pixels++ = src[3];
src += 4;
}
}
static void OneLine24(struct bmp_progressive_state *context)
{
gint X;
guchar *Pixels;
X = 0;
if (context->Header.Negative == 0)
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
(context->Header.height - context->Lines - 1));
else
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
context->Lines);
while (X < context->Header.width) {
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];
X++;
}
}
static void OneLine16(struct bmp_progressive_state *context)
{
int i;
guchar *pixels;
guchar *src;
if (!context->Header.Negative)
pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride * (context->Header.height - context->Lines - 1));
else
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);
src += 2;
}
}
static void OneLine8(struct bmp_progressive_state *context)
{
gint X;
guchar *Pixels;
X = 0;
if (context->Header.Negative == 0)
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
(context->Header.height - context->Lines - 1));
else
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
context->Lines);
while (X < context->Header.width) {
Pixels[X * 3 + 0] =
context->Colormap[context->buff[X]][2];
Pixels[X * 3 + 1] =
context->Colormap[context->buff[X]][1];
Pixels[X * 3 + 2] =
context->Colormap[context->buff[X]][0];
X++;
}
}
static void OneLine4(struct bmp_progressive_state *context)
{
gint X;
guchar *Pixels;
X = 0;
if (context->Header.Negative == 0)
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
(context->Header.height - context->Lines - 1));
else
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
context->Lines);
while (X < context->Header.width) {
guchar Pix;
Pix = context->buff[X / 2];
Pixels[X * 3 + 0] =
context->Colormap[Pix >> 4][2];
Pixels[X * 3 + 1] =
context->Colormap[Pix >> 4][1];
Pixels[X * 3 + 2] =
context->Colormap[Pix >> 4][0];
X++;
if (X < context->Header.width) {
/* Handle the other 4 bit pixel only when there is one */
Pixels[X * 3 + 0] =
context->Colormap[Pix & 15][2];
Pixels[X * 3 + 1] =
context->Colormap[Pix & 15][1];
Pixels[X * 3 + 2] =
context->Colormap[Pix & 15][0];
X++;
}
}
}
static void OneLine1(struct bmp_progressive_state *context)
{
gint X;
guchar *Pixels;
X = 0;
if (context->Header.Negative == 0)
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
(context->Header.height - context->Lines - 1));
else
Pixels = (context->pixbuf->pixels +
context->pixbuf->rowstride *
context->Lines);
while (X < context->Header.width) {
gint Bit;
Bit = (context->buff[X / 8]) >> (7 - (X & 7));
Bit = Bit & 1;
Pixels[X * 3 + 0] = context->Colormap[Bit][2];
Pixels[X * 3 + 1] = context->Colormap[Bit][1];
Pixels[X * 3 + 2] = context->Colormap[Bit][0];
X++;
}
}
static void OneLine(struct bmp_progressive_state *context)
{
context->BufferDone = 0;
if (context->Lines >= context->Header.height)
return;
if (context->Type == 32)
OneLine32(context);
else if (context->Type == 24)
OneLine24(context);
else if (context->Type == 16)
OneLine16(context);
else if (context->Type == 8)
OneLine8(context);
else if (context->Type == 4)
OneLine4(context);
else if (context->Type == 1)
OneLine1(context);
else
g_assert_not_reached ();
context->Lines++;
if (context->updated_func != NULL) {
(*context->updated_func) (context->pixbuf,
0,
context->Lines,
context->Header.width,
2,
context->user_data);
}
}
#define NEUTRAL 0
#define ENCODED 1
#define ESCAPE 2
#define DELTA_X 3
#define DELTA_Y 4
#define ABSOLUTE 5
#define SKIP 6
#define END_OF_LINE 0
#define END_OF_BITMAP 1
#define DELTA 2
static gboolean
DoCompressed(struct bmp_progressive_state *context, GError **error)
{
gint i, j;
gint y;
guchar c;
gint idx;
if (context->compr.y >= context->Header.height)
return TRUE;
y = context->compr.y;
for (i = 0; i < context->BufferSize; i++) {
c = context->buff[i];
switch (context->compr.phase) {
case NEUTRAL:
if (c) {
context->compr.run = c;
context->compr.phase = ENCODED;
}
else
context->compr.phase = ESCAPE;
break;
case ENCODED:
for (j = 0; j < context->compr.run; j++) {
if (context->Compressed == BI_RLE8)
idx = c;
else if (j & 1)
idx = c & 0x0f;
else
idx = (c >> 4) & 0x0f;
if (context->compr.x < context->Header.width) {
*context->compr.p++ = context->Colormap[idx][2];
*context->compr.p++ = context->Colormap[idx][1];
*context->compr.p++ = context->Colormap[idx][0];
*context->compr.p++ = 0xff;
context->compr.x++;
}
}
context->compr.phase = NEUTRAL;
break;
case ESCAPE:
switch (c) {
case END_OF_LINE:
context->compr.x = 0;
context->compr.y++;
context->compr.p = context->pixbuf->pixels
+ (context->pixbuf->rowstride * (context->Header.height - context->compr.y - 1))
+ (4 * context->compr.x);
context->compr.phase = NEUTRAL;
break;
case END_OF_BITMAP:
context->compr.x = 0;
context->compr.y = context->Header.height;
context->compr.phase = NEUTRAL;
break;
case DELTA:
context->compr.phase = DELTA_X;
break;
default:
context->compr.run = c;
context->compr.count = 0;
context->compr.phase = ABSOLUTE;
break;
}
break;
case DELTA_X:
context->compr.x += c;
context->compr.phase = DELTA_Y;
break;
case DELTA_Y:
context->compr.y += c;
context->compr.p = context->pixbuf->pixels
+ (context->pixbuf->rowstride * (context->Header.height - context->compr.y - 1))
+ (4 * context->compr.x);
context->compr.phase = NEUTRAL;
break;
case ABSOLUTE:
if (context->Compressed == BI_RLE8) {
idx = c;
if (context->compr.x < context->Header.width) {
*context->compr.p++ = context->Colormap[idx][2];
*context->compr.p++ = context->Colormap[idx][1];
*context->compr.p++ = context->Colormap[idx][0];
*context->compr.p++ = 0xff;
context->compr.x++;
}
context->compr.count++;
if (context->compr.count == context->compr.run) {
if (context->compr.run & 1)
context->compr.phase = SKIP;
else
context->compr.phase = NEUTRAL;
}
}
else {
for (j = 0; j < 2; j++) {
if (context->compr.count & 1)
idx = c & 0x0f;
else
idx = (c >> 4) & 0x0f;
if (context->compr.x < context->Header.width) {
*context->compr.p++ = context->Colormap[idx][2];
*context->compr.p++ = context->Colormap[idx][1];
*context->compr.p++ = context->Colormap[idx][0];
*context->compr.p++ = 0xff;
context->compr.x++;
}
context->compr.count++;
if (context->compr.count == context->compr.run) {
if ((context->compr.run & 3) == 1
|| (context->compr.run & 3) == 2)
context->compr.phase = SKIP;
else
context->compr.phase = NEUTRAL;
break;
}
}
}
break;
case SKIP:
context->compr.phase = NEUTRAL;
break;
}
}
if (context->updated_func != NULL) {
if (context->compr.y > y)
(*context->updated_func) (context->pixbuf,
0,
y,
context->Header.width,
context->compr.y - y,
context->user_data);
}
context->BufferDone = 0;
return TRUE;
}
/*
* context - from image_begin_load
* buf - new image data
* size - length of new image data
*
* append image data onto inrecrementally built output image
*/
static gboolean
gdk_pixbuf__bmp_image_load_increment(gpointer data,
const guchar * buf,
guint size,
GError **error)
{
struct bmp_progressive_state *context =
(struct bmp_progressive_state *) data;
gint BytesToCopy;
if (context->read_state == READ_STATE_DONE)
return TRUE;
else if (context->read_state == READ_STATE_ERROR)
return FALSE;
while (size > 0) {
if (context->BufferDone < context->BufferSize) { /* We still
have headerbytes to do */
BytesToCopy =
context->BufferSize - context->BufferDone;
if (BytesToCopy > size)
BytesToCopy = size;
memmove(context->buff + context->BufferDone,
buf, BytesToCopy);
size -= BytesToCopy;
buf += BytesToCopy;
context->BufferDone += BytesToCopy;
if (context->BufferDone != context->BufferSize)
break;
}
switch (context->read_state) {
case READ_STATE_HEADERS:
if (!DecodeHeader (context->buff,
context->buff + 14, context,
error))
return FALSE;
break;
case READ_STATE_PALETTE:
if (!DecodeColormap (context->buff, context, error))
return FALSE;
break;
case READ_STATE_BITMASKS:
if (!decode_bitmasks (context->buff, context, error))
return FALSE;
break;
case READ_STATE_DATA:
if (context->Compressed == BI_RGB || context->Compressed == BI_BITFIELDS)
OneLine (context);
else if (!DoCompressed (context, error))
return FALSE;
break;
default:
g_assert_not_reached ();
}
}
return TRUE;
}
void
gdk_pixbuf__bmp_fill_vtable (GdkPixbufModule *module)
{
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;
}