mirror of https://github.com/OpenTTD/OpenTTD.git
(svn r22872) -Fix [FS#4746]: Improve handling of slightly invalid BMP files using the under-specified RLE compression. Improve coding style while at it as well. (Based on patch by monoid)
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michi_cc
parent
73624abd5e
commit
655d45e7d3
155
src/bmp.cpp
155
src/bmp.cpp
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@ -130,54 +130,63 @@ static inline bool BmpRead4(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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*/
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static inline bool BmpRead4Rle(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint i;
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uint x = 0;
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uint y = info->height - 1;
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byte n, c, b;
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byte *pixel = &data->bitmap[y * info->width];
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while (y != 0 || x < info->width) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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n = ReadByte(buffer);
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c = ReadByte(buffer);
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byte n = ReadByte(buffer);
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byte c = ReadByte(buffer);
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if (n == 0) {
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switch (c) {
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case 0: // end of line
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x = 0;
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if (y == 0) return false;
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pixel = &data->bitmap[--y * info->width];
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break;
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case 1: // end of bitmap
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x = info->width;
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y = 0;
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pixel = NULL;
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break;
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case 2: // delta
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x += ReadByte(buffer);
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i = ReadByte(buffer);
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if (x >= info->width || i > y) return false;
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y -= i;
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pixel = &data->bitmap[y * info->width + x];
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break;
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default: // uncompressed
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i = 0;
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while (i++ < c) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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b = ReadByte(buffer);
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*pixel++ = GB(b, 4, 4);
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x++;
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if (x < info->width && i++ < c) {
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*pixel++ = GB(b, 0, 4);
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x++;
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}
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case 0: // end of line
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x = 0;
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if (y == 0) return false;
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pixel = &data->bitmap[--y * info->width];
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break;
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case 1: // end of bitmap
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return true;
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case 2: { // delta
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if (EndOfBuffer(buffer)) return false;
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byte dx = ReadByte(buffer);
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byte dy = ReadByte(buffer);
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/* Check for over- and underflow. */
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if (x + dx >= info->width || x + dx < x || dy > y) return false;
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x += dx;
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y -= dy;
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pixel = &data->bitmap[y * info->width + x];
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break;
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}
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default: { // uncompressed
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uint i = 0;
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while (i++ < c) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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byte b = ReadByte(buffer);
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*pixel++ = GB(b, 4, 4);
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x++;
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if (i++ < c) {
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if (x >= info->width) return false;
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*pixel++ = GB(b, 0, 4);
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x++;
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}
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}
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/* Padding for 16 bit align */
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SkipBytes(buffer, ((c + 1) / 2) % 2);
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break;
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}
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/* Padding for 16 bit align */
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SkipBytes(buffer, ((c + 1) / 2) % 2);
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break;
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}
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} else {
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i = 0;
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while (i++ < n) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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/* Apparently it is common to encounter BMPs where the count of
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* pixels to be written is higher than the remaining line width.
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* Ignore the superfluous pixels instead of reporting an error. */
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uint i = 0;
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while (x < info->width && i++ < n) {
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*pixel++ = GB(c, 4, 4);
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x++;
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if (x < info->width && i++ < n) {
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@ -214,47 +223,55 @@ static inline bool BmpRead8(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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*/
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static inline bool BmpRead8Rle(BmpBuffer *buffer, BmpInfo *info, BmpData *data)
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{
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uint i;
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uint x = 0;
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uint y = info->height - 1;
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byte n, c;
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byte *pixel = &data->bitmap[y * info->width];
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while (y != 0 || x < info->width) {
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if (EndOfBuffer(buffer)) return false; // the file is shorter than expected
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n = ReadByte(buffer);
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c = ReadByte(buffer);
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byte n = ReadByte(buffer);
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byte c = ReadByte(buffer);
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if (n == 0) {
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switch (c) {
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case 0: // end of line
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x = 0;
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if (y == 0) return false;
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pixel = &data->bitmap[--y * info->width];
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break;
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case 1: // end of bitmap
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x = info->width;
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y = 0;
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pixel = NULL;
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break;
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case 2: // delta
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x += ReadByte(buffer);
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i = ReadByte(buffer);
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if (x >= info->width || i > y) return false;
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y -= i;
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pixel = &data->bitmap[y * info->width + x];
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break;
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default: // uncompressed
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for (i = 0; i < c; i++) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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*pixel++ = ReadByte(buffer);
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x++;
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case 0: // end of line
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x = 0;
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if (y == 0) return false;
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pixel = &data->bitmap[--y * info->width];
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break;
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case 1: // end of bitmap
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return true;
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case 2: { // delta
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if (EndOfBuffer(buffer)) return false;
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byte dx = ReadByte(buffer);
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byte dy = ReadByte(buffer);
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/* Check for over- and underflow. */
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if (x + dx >= info->width || x + dx < x || dy > y) return false;
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x += dx;
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y -= dy;
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pixel = &data->bitmap[y * info->width + x];
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break;
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}
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default: { // uncompressed
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for (uint i = 0; i < c; i++) {
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if (EndOfBuffer(buffer) || x >= info->width) return false;
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*pixel++ = ReadByte(buffer);
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x++;
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}
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/* Padding for 16 bit align */
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SkipBytes(buffer, c % 2);
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break;
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}
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/* Padding for 16 bit align */
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SkipBytes(buffer, c % 2);
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break;
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}
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} else {
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for (i = 0; i < n; i++) {
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if (x >= info->width) return false;
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/* Apparently it is common to encounter BMPs where the count of
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* pixels to be written is higher than the remaining line width.
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* Ignore the superfluous pixels instead of reporting an error. */
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for (uint i = 0; x < info->width && i < n; i++) {
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*pixel++ = c;
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x++;
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}
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