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/*
gd_bmp.c
Bitmap format support for libgd
* Written 2007, Scott MacVicar
---------------------------------------------------------------------------
Todo:
Bitfield encoding
----------------------------------------------------------------------------
*/
/* $Id$ */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"
#include "gdhelpers.h"
#include "bmp.h"
static int compress_row(unsigned char *uncompressed_row, int length);
static int build_rle_packet(unsigned char *row, int packet_type, int length, unsigned char *data);
static int bmp_read_header(gdIOCtxPtr infile, bmp_hdr_t *hdr);
static int bmp_read_info(gdIOCtxPtr infile, bmp_info_t *info);
static int bmp_read_windows_v3_info(gdIOCtxPtr infile, bmp_info_t *info);
static int bmp_read_os2_v1_info(gdIOCtxPtr infile, bmp_info_t *info);
static int bmp_read_os2_v2_info(gdIOCtxPtr infile, bmp_info_t *info);
static int bmp_read_direct(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
static int bmp_read_1bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
static int bmp_read_4bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
static int bmp_read_8bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header);
static int bmp_read_rle(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info);
#define BMP_DEBUG(s)
static int gdBMPPutWord(gdIOCtx *out, int w)
{
/* Byte order is little-endian */
gdPutC(w & 0xFF, out);
gdPutC((w >> 8) & 0xFF, out);
return 0;
}
static int gdBMPPutInt(gdIOCtx *out, int w)
{
/* Byte order is little-endian */
gdPutC(w & 0xFF, out);
gdPutC((w >> 8) & 0xFF, out);
gdPutC((w >> 16) & 0xFF, out);
gdPutC((w >> 24) & 0xFF, out);
return 0;
}
/*
Function: gdImageBmpPtr
*/
BGD_DECLARE(void *) gdImageBmpPtr(gdImagePtr im, int *size, int compression)
{
void *rv;
gdIOCtx *out = gdNewDynamicCtx(2048, NULL);
if (out == NULL) return NULL;
gdImageBmpCtx(im, out, compression);
rv = gdDPExtractData(out, size);
out->gd_free(out);
return rv;
}
/*
Function: gdImageBmp
*/
BGD_DECLARE(void) gdImageBmp(gdImagePtr im, FILE *outFile, int compression)
{
gdIOCtx *out = gdNewFileCtx(outFile);
if (out == NULL) return;
gdImageBmpCtx(im, out, compression);
out->gd_free(out);
}
/*
Function: gdImageBmpCtx
*/
BGD_DECLARE(void) gdImageBmpCtx(gdImagePtr im, gdIOCtxPtr out, int compression)
{
int bitmap_size = 0, info_size, total_size, padding;
int i, row, xpos, pixel;
int error = 0;
unsigned char *uncompressed_row = NULL, *uncompressed_row_start = NULL;
FILE *tmpfile_for_compression = NULL;
gdIOCtxPtr out_original = NULL;
/* No compression if its true colour or we don't support seek */
if (im->trueColor) {
compression = 0;
}
if (compression == 1 && !out->seek) {
/* Try to create a temp file where we can seek */
if ((tmpfile_for_compression = tmpfile()) == NULL) {
compression = 0;
} else {
out_original = out;
if ((out = (gdIOCtxPtr)gdNewFileCtx(tmpfile_for_compression)) == NULL) {
out = out_original;
out_original = NULL;
compression = 0;
}
}
}
bitmap_size = ((im->sx * (im->trueColor ? 24 : 8)) / 8) * im->sy;
/* 40 byte Windows v3 header */
info_size = BMP_WINDOWS_V3;
/* data for the palette */
if (!im->trueColor) {
info_size += im->colorsTotal * 4;
if (compression) {
bitmap_size = 0;
}
}
/* bitmap header + info header + data */
total_size = 14 + info_size + bitmap_size;
/* write bmp header info */
gdPutBuf("BM", 2, out);
gdBMPPutInt(out, total_size);
gdBMPPutWord(out, 0);
gdBMPPutWord(out, 0);
gdBMPPutInt(out, 14 + info_size);
/* write Windows v3 headers */
gdBMPPutInt(out, BMP_WINDOWS_V3); /* header size */
gdBMPPutInt(out, im->sx); /* width */
gdBMPPutInt(out, im->sy); /* height */
gdBMPPutWord(out, 1); /* colour planes */
gdBMPPutWord(out, (im->trueColor ? 24 : 8)); /* bit count */
gdBMPPutInt(out, (compression ? BMP_BI_RLE8 : BMP_BI_RGB)); /* compression */
gdBMPPutInt(out, bitmap_size); /* image size */
gdBMPPutInt(out, 0); /* H resolution */
gdBMPPutInt(out, 0); /* V ressolution */
gdBMPPutInt(out, im->colorsTotal); /* colours used */
gdBMPPutInt(out, 0); /* important colours */
/* The line must be divisible by 4, else its padded with NULLs */
padding = ((int)(im->trueColor ? 3 : 1) * im->sx) % 4;
if (padding) {
padding = 4 - padding;
}
/* 8-bit colours */
if (!im->trueColor) {
for(i = 0; i< im->colorsTotal; ++i) {
Putchar(gdImageBlue(im, i), out);
Putchar(gdImageGreen(im, i), out);
Putchar(gdImageRed(im, i), out);
Putchar(0, out);
}
if (compression) {
/* Can potentially change this to X + ((X / 128) * 3) */
uncompressed_row = uncompressed_row_start = (unsigned char *) gdCalloc(gdImageSX(im) * 2, sizeof(char));
if (!uncompressed_row) {
/* malloc failed */
goto cleanup;
}
}
for (row = (im->sy - 1); row >= 0; row--) {
if (compression) {
memset (uncompressed_row, 0, gdImageSX(im));
}
for (xpos = 0; xpos < im->sx; xpos++) {
if (compression) {
*uncompressed_row++ = (unsigned char)gdImageGetPixel(im, xpos, row);
} else {
Putchar(gdImageGetPixel(im, xpos, row), out);
}
}
if (!compression) {
/* Add padding to make sure we have n mod 4 == 0 bytes per row */
for (xpos = padding; xpos > 0; --xpos) {
Putchar('\0', out);
}
} else {
int compressed_size = 0;
uncompressed_row = uncompressed_row_start;
if ((compressed_size = compress_row(uncompressed_row, gdImageSX(im))) < 0) {
error = 1;
break;
}
bitmap_size += compressed_size;
gdPutBuf(uncompressed_row, compressed_size, out);
Putchar(BMP_RLE_COMMAND, out);
Putchar(BMP_RLE_ENDOFLINE, out);
bitmap_size += 2;
}
}
if (compression && uncompressed_row) {
gdFree(uncompressed_row);
if (error != 0) {
goto cleanup;
}
/* Update filesize based on new values and set compression flag */
Putchar(BMP_RLE_COMMAND, out);
Putchar(BMP_RLE_ENDOFBITMAP, out);
bitmap_size += 2;
/* Write new total bitmap size */
gdSeek(out, 2);
gdBMPPutInt(out, total_size + bitmap_size);
/* Total length of image data */
gdSeek(out, 34);
gdBMPPutInt(out, bitmap_size);
}
} else {
for (row = (im->sy - 1); row >= 0; row--) {
for (xpos = 0; xpos < im->sx; xpos++) {
pixel = gdImageGetPixel(im, xpos, row);
Putchar(gdTrueColorGetBlue(pixel), out);
Putchar(gdTrueColorGetGreen(pixel), out);
Putchar(gdTrueColorGetRed(pixel), out);
}
/* Add padding to make sure we have n mod 4 == 0 bytes per row */
for (xpos = padding; xpos > 0; --xpos) {
Putchar('\0', out);
}
}
}
/* If we needed a tmpfile for compression copy it over to out_original */
if (tmpfile_for_compression) {
unsigned char* copy_buffer = NULL;
int buffer_size = 0;
gdSeek(out, 0);
copy_buffer = (unsigned char *) gdMalloc(1024 * sizeof(unsigned char));
if (copy_buffer == NULL) {
goto cleanup;
}
while ((buffer_size = gdGetBuf(copy_buffer, 1024, out)) != EOF) {
if (buffer_size == 0) {
break;
}
gdPutBuf(copy_buffer , buffer_size, out_original);
}
gdFree(copy_buffer);
/* Replace the temp with the original which now has data */
out->gd_free(out);
out = out_original;
out_original = NULL;
}
cleanup:
if (tmpfile_for_compression) {
#ifdef _WIN32
_rmtmp();
#else
fclose(tmpfile_for_compression);
#endif
tmpfile_for_compression = NULL;
}
if (out_original) {
out_original->gd_free(out_original);
}
return;
}
static int compress_row(unsigned char *row, int length)
{
int rle_type = 0;
int compressed_length = 0;
int pixel = 0, compressed_run = 0, rle_compression = 0;
unsigned char *uncompressed_row = NULL, *uncompressed_rowp = NULL, *uncompressed_start = NULL;
uncompressed_row = (unsigned char *) gdMalloc(length);
if (!uncompressed_row) {
return -1;
}
memcpy(uncompressed_row, row, length);
uncompressed_start = uncompressed_rowp = uncompressed_row;
for (pixel = 0; pixel < length; pixel++) {
if (compressed_run == 0) {
uncompressed_row = uncompressed_rowp;
compressed_run++;
uncompressed_rowp++;
rle_type = BMP_RLE_TYPE_RAW;
continue;
}
if (compressed_run == 1) {
/* Compare next byte */
if (memcmp(uncompressed_rowp, uncompressed_rowp - 1, 1) == 0) {
rle_type = BMP_RLE_TYPE_RLE;
}
}
if (rle_type == BMP_RLE_TYPE_RLE) {
if (compressed_run >= 128 || memcmp(uncompressed_rowp, uncompressed_rowp - 1, 1) != 0) {
/* more than what we can store in a single run or run is over due to non match, force write */
rle_compression = build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
row += rle_compression;
compressed_length += rle_compression;
compressed_run = 0;
pixel--;
} else {
compressed_run++;
uncompressed_rowp++;
}
} else {
if (compressed_run >= 128 || memcmp(uncompressed_rowp, uncompressed_rowp - 1, 1) == 0) {
/* more than what we can store in a single run or run is over due to match, force write */
rle_compression = build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
row += rle_compression;
compressed_length += rle_compression;
compressed_run = 0;
pixel--;
} else {
/* add this pixel to the row */
compressed_run++;
uncompressed_rowp++;
}
}
}
if (compressed_run) {
if (rle_type == BMP_RLE_TYPE_RLE) {
compressed_length += build_rle_packet(row, rle_type, compressed_run, uncompressed_row);
}
}
gdFree(uncompressed_start);
return compressed_length;
}
static int build_rle_packet(unsigned char *row, int packet_type, int length, unsigned char *data)
{
int compressed_size = 0;
if (length < 1 || length > 128) {
return 0;
}
/* Bitmap specific cases is that we can't have uncompressed rows of length 1 or 2 */
if (packet_type == BMP_RLE_TYPE_RAW && length < 3) {
int i = 0;
for (i = 0; i < length; i++) {
compressed_size += 2;
memset(row, 1, 1);
row++;
memcpy(row, data++, 1);
row++;
}
} else if (packet_type == BMP_RLE_TYPE_RLE) {
compressed_size = 2;
memset(row, length, 1);
row++;
memcpy(row, data, 1);
row++;
} else {
compressed_size = 2 + length;
memset(row, BMP_RLE_COMMAND, 1);
row++;
memset(row, length, 1);
row++;
memcpy(row, data, length);
row += length;
/* Must be an even number for an uncompressed run */
if (length % 2) {
memset(row, 0, 1);
row++;
compressed_size++;
}
}
return compressed_size;
}
/*
Function: gdImageCreateFromBmp
*/
BGD_DECLARE(gdImagePtr) gdImageCreateFromBmp(FILE * inFile)
{
gdImagePtr im = 0;
gdIOCtx *in = gdNewFileCtx(inFile);
if (in == NULL) return NULL;
im = gdImageCreateFromBmpCtx(in);
in->gd_free(in);
return im;
}
/*
Function: gdImageCreateFromBmpPtr
*/
BGD_DECLARE(gdImagePtr) gdImageCreateFromBmpPtr(int size, void *data)
{
gdImagePtr im;
gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);
if (in == NULL) return NULL;
im = gdImageCreateFromBmpCtx(in);
in->gd_free(in);
return im;
}
/*
Function: gdImageCreateFromBmpCtx
*/
BGD_DECLARE(gdImagePtr) gdImageCreateFromBmpCtx(gdIOCtxPtr infile)
{
bmp_hdr_t *hdr;
bmp_info_t *info;
gdImagePtr im = NULL;
int error = 0;
if (!(hdr= (bmp_hdr_t *)gdCalloc(1, sizeof(bmp_hdr_t)))) {
return NULL;
}
if (bmp_read_header(infile, hdr)) {
gdFree(hdr);
return NULL;
}
if (hdr->magic != 0x4d42) {
gdFree(hdr);
return NULL;
}
if (!(info = (bmp_info_t *)gdCalloc(1, sizeof(bmp_info_t)))) {
gdFree(hdr);
return NULL;
}
if (bmp_read_info(infile, info)) {
gdFree(hdr);
gdFree(info);
return NULL;
}
BMP_DEBUG(printf("Numcolours: %d\n", info->numcolors));
BMP_DEBUG(printf("Width: %d\n", info->width));
BMP_DEBUG(printf("Height: %d\n", info->height));
BMP_DEBUG(printf("Planes: %d\n", info->numplanes));
BMP_DEBUG(printf("Depth: %d\n", info->depth));
BMP_DEBUG(printf("Offset: %d\n", hdr->off));
if (info->depth >= 16) {
im = gdImageCreateTrueColor(info->width, info->height);
} else {
im = gdImageCreate(info->width, info->height);
}
if (!im) {
gdFree(hdr);
gdFree(info);
return NULL;
}
switch (info->depth) {
case 1:
BMP_DEBUG(printf("1-bit image\n"));
error = bmp_read_1bit(im, infile, info, hdr);
break;
case 4:
BMP_DEBUG(printf("4-bit image\n"));
error = bmp_read_4bit(im, infile, info, hdr);
break;
case 8:
BMP_DEBUG(printf("8-bit image\n"));
error = bmp_read_8bit(im, infile, info, hdr);
break;
case 16:
case 24:
case 32:
BMP_DEBUG(printf("Direct BMP image\n"));
error = bmp_read_direct(im, infile, info, hdr);
break;
default:
BMP_DEBUG(printf("Unknown bit count\n"));
error = 1;
}
gdFree(hdr);
gdFree(info);
if (error) {
gdImageDestroy(im);
return NULL;
}
return im;
}
static int bmp_read_header(gdIOCtx *infile, bmp_hdr_t *hdr)
{
if(
!gdGetWordLSB(&hdr->magic, infile) ||
!gdGetIntLSB(&hdr->size, infile) ||
!gdGetWordLSB(&hdr->reserved1, infile) ||
!gdGetWordLSB(&hdr->reserved2 , infile) ||
!gdGetIntLSB(&hdr->off , infile)
) {
return 1;
}
return 0;
}
static int bmp_read_info(gdIOCtx *infile, bmp_info_t *info)
{
/* read BMP length so we can work out the version */
if (!gdGetIntLSB(&info->len, infile)) {
return 1;
}
switch (info->len) {
/* For now treat Windows v4 + v5 as v3 */
case BMP_WINDOWS_V3:
case BMP_WINDOWS_V4:
case BMP_WINDOWS_V5:
BMP_DEBUG(printf("Reading Windows Header\n"));
if (bmp_read_windows_v3_info(infile, info)) {
return 1;
}
break;
case BMP_OS2_V1:
if (bmp_read_os2_v1_info(infile, info)) {
return 1;
}
break;
case BMP_OS2_V2:
if (bmp_read_os2_v2_info(infile, info)) {
return 1;
}
break;
default:
BMP_DEBUG(printf("Unhandled bitmap\n"));
return 1;
}
return 0;
}
static int bmp_read_windows_v3_info(gdIOCtxPtr infile, bmp_info_t *info)
{
if (
!gdGetIntLSB(&info->width, infile) ||
!gdGetIntLSB(&info->height, infile) ||
!gdGetWordLSB(&info->numplanes, infile) ||
!gdGetWordLSB(&info->depth, infile) ||
!gdGetIntLSB(&info->enctype, infile) ||
!gdGetIntLSB(&info->size, infile) ||
!gdGetIntLSB(&info->hres, infile) ||
!gdGetIntLSB(&info->vres, infile) ||
!gdGetIntLSB(&info->numcolors, infile) ||
!gdGetIntLSB(&info->mincolors, infile)
) {
return 1;
}
if (info->height < 0) {
info->topdown = 1;
info->height = -info->height;
} else {
info->topdown = 0;
}
info->type = BMP_PALETTE_4;
if (info->width <= 0 || info->height <= 0 || info->numplanes <= 0 ||
info->depth <= 0 || info->numcolors < 0 || info->mincolors < 0) {
return 1;
}
return 0;
}
static int bmp_read_os2_v1_info(gdIOCtxPtr infile, bmp_info_t *info)
{
if (
!gdGetWordLSB((signed short int *)&info->width, infile) ||
!gdGetWordLSB((signed short int *)&info->height, infile) ||
!gdGetWordLSB(&info->numplanes, infile) ||
!gdGetWordLSB(&info->depth, infile)
) {
return 1;
}
/* OS2 v1 doesn't support topdown */
info->topdown = 0;
info->numcolors = 1 << info->depth;
info->type = BMP_PALETTE_3;
if (info->width <= 0 || info->height <= 0 || info->numplanes <= 0 ||
info->depth <= 0 || info->numcolors < 0) {
return 1;
}
return 0;
}
static int bmp_read_os2_v2_info(gdIOCtxPtr infile, bmp_info_t *info)
{
char useless_bytes[24];
if (
!gdGetIntLSB(&info->width, infile) ||
!gdGetIntLSB(&info->height, infile) ||
!gdGetWordLSB(&info->numplanes, infile) ||
!gdGetWordLSB(&info->depth, infile) ||
!gdGetIntLSB(&info->enctype, infile) ||
!gdGetIntLSB(&info->size, infile) ||
!gdGetIntLSB(&info->hres, infile) ||
!gdGetIntLSB(&info->vres, infile) ||
!gdGetIntLSB(&info->numcolors, infile) ||
!gdGetIntLSB(&info->mincolors, infile)
) {
return 1;
}
/* Lets seek the next 24 pointless bytes, we don't care too much about it */
if (!gdGetBuf(useless_bytes, 24, infile)) {
return 1;
}
if (info->height < 0) {
info->topdown = 1;
info->height = -info->height;
} else {
info->topdown = 0;
}
info->type = BMP_PALETTE_4;
if (info->width <= 0 || info->height <= 0 || info->numplanes <= 0 ||
info->depth <= 0 || info->numcolors < 0 || info->mincolors < 0) {
return 1;
}
return 0;
}
static int bmp_read_direct(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
{
int ypos = 0, xpos = 0, row = 0;
int padding = 0, alpha = 0, red = 0, green = 0, blue = 0;
signed short int data = 0;
switch(info->enctype) {
case BMP_BI_RGB:
/* no-op */
break;
case BMP_BI_BITFIELDS:
if (info->depth == 24) {
BMP_DEBUG(printf("Bitfield compression isn't supported for 24-bit\n"));
return 1;
}
BMP_DEBUG(printf("Currently no bitfield support\n"));
return 1;
break;
case BMP_BI_RLE8:
if (info->depth != 8) {
BMP_DEBUG(printf("RLE is only valid for 8-bit images\n"));
return 1;
}
break;
case BMP_BI_RLE4:
if (info->depth != 4) {
BMP_DEBUG(printf("RLE is only valid for 4-bit images\n"));
return 1;
}
break;
case BMP_BI_JPEG:
case BMP_BI_PNG:
default:
BMP_DEBUG(printf("Unsupported BMP compression format\n"));
return 1;
}
/* There is a chance the data isn't until later, would be wierd but it is possible */
if (gdTell(infile) != header->off) {
/* Should make sure we don't seek past the file size */
gdSeek(infile, header->off);
}
/* The line must be divisible by 4, else its padded with NULLs */
padding = ((int)(info->depth / 8) * info->width) % 4;
if (padding) {
padding = 4 - padding;
}
for (ypos = 0; ypos < info->height; ++ypos) {
if (info->topdown) {
row = ypos;
} else {
row = info->height - ypos - 1;
}
for (xpos = 0; xpos < info->width; xpos++) {
if (info->depth == 16) {
if (!gdGetWordLSB(&data, infile)) {
return 1;
}
BMP_DEBUG(printf("Data: %X\n", data));
red = ((data & 0x7C00) >> 10) << 3;
green = ((data & 0x3E0) >> 5) << 3;
blue = (data & 0x1F) << 3;
BMP_DEBUG(printf("R: %d, G: %d, B: %d\n", red, green, blue));
} else if (info->depth == 24) {
if (!gdGetByte(&blue, infile) || !gdGetByte(&green, infile) || !gdGetByte(&red, infile)) {
return 1;
}
} else {
if (!gdGetByte(&blue, infile) || !gdGetByte(&green, infile) || !gdGetByte(&red, infile) || !gdGetByte(&alpha, infile)) {
return 1;
}
}
/*alpha = gdAlphaMax - (alpha >> 1);*/
gdImageSetPixel(im, xpos, row, gdTrueColor(red, green, blue));
}
for (xpos = padding; xpos > 0; --xpos) {
if (!gdGetByte(&red, infile)) {
return 1;
}
}
}
return 0;
}
static int bmp_read_palette(gdImagePtr im, gdIOCtxPtr infile, int count, int read_four)
{
int i;
int r, g, b, z;
for (i = 0; i < count; i++) {
if (
!gdGetByte(&b, infile) ||
!gdGetByte(&g, infile) ||
!gdGetByte(&r, infile) ||
(read_four && !gdGetByte(&z, infile))
) {
return 1;
}
im->red[i] = r;
im->green[i] = g;
im->blue[i] = b;
im->open[i] = 1;
}
return 0;
}
static int bmp_read_1bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
{
int ypos = 0, xpos = 0, row = 0, index = 0;
int padding = 0, current_byte = 0, bit = 0;
if (info->enctype != BMP_BI_RGB) {
return 1;
}
if (!info->numcolors) {
info->numcolors = 2;
} else if (info->numcolors < 0 || info->numcolors > 2) {
return 1;
}
if (bmp_read_palette(im, infile, info->numcolors, (info->type == BMP_PALETTE_4))) {
return 1;
}
im->colorsTotal = info->numcolors;
/* There is a chance the data isn't until later, would be wierd but it is possible */
if (gdTell(infile) != header->off) {
/* Should make sure we don't seek past the file size */
gdSeek(infile, header->off);
}
/* The line must be divisible by 4, else its padded with NULLs */
padding = ((int)ceil(0.1 * info->width)) % 4;
if (padding) {
padding = 4 - padding;
}
for (ypos = 0; ypos < info->height; ++ypos) {
if (info->topdown) {
row = ypos;
} else {
row = info->height - ypos - 1;
}
for (xpos = 0; xpos < info->width; xpos += 8) {
/* Bitmaps are always aligned in bytes so we'll never overflow */
if (!gdGetByte(¤t_byte, infile)) {
return 1;
}
for (bit = 0; bit < 8; bit++) {
index = ((current_byte & (0x80 >> bit)) != 0 ? 0x01 : 0x00);
if (im->open[index]) {
im->open[index] = 0;
}
gdImageSetPixel(im, xpos + bit, row, index);
/* No need to read anything extra */
if ((xpos + bit) >= info->width) {
break;
}
}
}
for (xpos = padding; xpos > 0; --xpos) {
if (!gdGetByte(&index, infile)) {
return 1;
}
}
}
return 0;
}
static int bmp_read_4bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
{
int ypos = 0, xpos = 0, row = 0, index = 0;
int padding = 0, current_byte = 0;
if (info->enctype != BMP_BI_RGB && info->enctype != BMP_BI_RLE4) {
return 1;
}
if (!info->numcolors) {
info->numcolors = 16;
} else if (info->numcolors < 0 || info->numcolors > 16) {
return 1;
}
if (bmp_read_palette(im, infile, info->numcolors, (info->type == BMP_PALETTE_4))) {
return 1;
}
im->colorsTotal = info->numcolors;
/* There is a chance the data isn't until later, would be wierd but it is possible */
if (gdTell(infile) != header->off) {
/* Should make sure we don't seek past the file size */
gdSeek(infile, header->off);
}
/* The line must be divisible by 4, else its padded with NULLs */
padding = ((int)ceil(0.5 * info->width)) % 4;
if (padding) {
padding = 4 - padding;
}
switch (info->enctype) {
case BMP_BI_RGB:
for (ypos = 0; ypos < info->height; ++ypos) {
if (info->topdown) {
row = ypos;
} else {
row = info->height - ypos - 1;
}
for (xpos = 0; xpos < info->width; xpos += 2) {
if (!gdGetByte(¤t_byte, infile)) {
return 1;
}
index = (current_byte >> 4) & 0x0f;
if (im->open[index]) {
im->open[index] = 0;
}
gdImageSetPixel(im, xpos, row, index);
/* This condition may get called often, potential optimsations */
if (xpos >= info->width) {
break;
}
index = current_byte & 0x0f;
if (im->open[index]) {
im->open[index] = 0;
}
gdImageSetPixel(im, xpos + 1, row, index);
}
for (xpos = padding; xpos > 0; --xpos) {
if (!gdGetByte(&index, infile)) {
return 1;
}
}
}
break;
case BMP_BI_RLE4:
if (bmp_read_rle(im, infile, info)) {
return 1;
}
break;
default:
return 1;
}
return 0;
}
static int bmp_read_8bit(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info, bmp_hdr_t *header)
{
int ypos = 0, xpos = 0, row = 0, index = 0;
int padding = 0;
if (info->enctype != BMP_BI_RGB && info->enctype != BMP_BI_RLE8) {
return 1;
}
if (!info->numcolors) {
info->numcolors = 256;
} else if (info->numcolors < 0 || info->numcolors > 256) {
return 1;
}
if (bmp_read_palette(im, infile, info->numcolors, (info->type == BMP_PALETTE_4))) {
return 1;
}
im->colorsTotal = info->numcolors;
/* There is a chance the data isn't until later, would be wierd but it is possible */
if (gdTell(infile) != header->off) {
/* Should make sure we don't seek past the file size */
gdSeek(infile, header->off);
}
/* The line must be divisible by 4, else its padded with NULLs */
padding = (1 * info->width) % 4;
if (padding) {
padding = 4 - padding;
}
switch (info->enctype) {
case BMP_BI_RGB:
for (ypos = 0; ypos < info->height; ++ypos) {
if (info->topdown) {
row = ypos;
} else {
row = info->height - ypos - 1;
}
for (xpos = 0; xpos < info->width; ++xpos) {
if (!gdGetByte(&index, infile)) {
return 1;
}
if (im->open[index]) {
im->open[index] = 0;
}
gdImageSetPixel(im, xpos, row, index);
}
/* Could create a new variable, but it isn't really worth it */
for (xpos = padding; xpos > 0; --xpos) {
if (!gdGetByte(&index, infile)) {
return 1;
}
}
}
break;
case BMP_BI_RLE8:
if (bmp_read_rle(im, infile, info)) {
return 1;
}
break;
default:
return 1;
}
return 0;
}
static int bmp_read_rle(gdImagePtr im, gdIOCtxPtr infile, bmp_info_t *info)
{
int ypos = 0, xpos = 0, row = 0, index = 0;
int rle_length = 0, rle_data = 0;
int padding = 0;
int i = 0, j = 0;
int pixels_per_byte = 8 / info->depth;
for (ypos = 0; ypos < info->height && xpos <= info->width;) {
if (!gdGetByte(&rle_length, infile) || !gdGetByte(&rle_data, infile)) {
return 1;
}
row = info->height - ypos - 1;
if (rle_length != BMP_RLE_COMMAND) {
if (im->open[rle_data]) {
im->open[rle_data] = 0;
}
for (i = 0; (i < rle_length) && (xpos < info->width);) {
for (j = 1; (j <= pixels_per_byte) && (xpos < info->width) && (i < rle_length); j++, xpos++, i++) {
index = (rle_data & (((1 << info->depth) - 1) << (8 - (j * info->depth)))) >> (8 - (j * info->depth));
if (im->open[index]) {
im->open[index] = 0;
}
gdImageSetPixel(im, xpos, row, index);
}
}
} else if (rle_length == BMP_RLE_COMMAND && rle_data > 2) {
/* Uncompressed RLE needs to be even */
padding = 0;
for (i = 0; (i < rle_data) && (xpos < info->width); i += pixels_per_byte) {
int max_pixels = pixels_per_byte;
if (!gdGetByte(&index, infile)) {
return 1;
}
padding++;
if (rle_data - i < max_pixels) {
max_pixels = rle_data - i;
}
for (j = 1; (j <= max_pixels) && (xpos < info->width); j++, xpos++) {
int temp = (index >> (8 - (j * info->depth))) & ((1 << info->depth) - 1);
if (im->open[temp]) {
im->open[temp] = 0;
}
gdImageSetPixel(im, xpos, row, temp);
}
}
/* Make sure the bytes read are even */
if (padding % 2 && !gdGetByte(&index, infile)) {
return 1;
}
} else if (rle_length == BMP_RLE_COMMAND && rle_data == BMP_RLE_ENDOFLINE) {
/* Next Line */
xpos = 0;
ypos++;
} else if (rle_length == BMP_RLE_COMMAND && rle_data == BMP_RLE_DELTA) {
/* Delta Record, used for bmp files that contain other data*/
if (!gdGetByte(&rle_length, infile) || !gdGetByte(&rle_data, infile)) {
return 1;
}
xpos += rle_length;
ypos += rle_data;
} else if (rle_length == BMP_RLE_COMMAND && rle_data == BMP_RLE_ENDOFBITMAP) {
/* End of bitmap */
break;
}
}
return 0;
}
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