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Differential D11057 Diff 36451 source/blender/imbuf/intern/bmp.c

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source/blender/imbuf/intern/bmp.c

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#define CHECK_HEADER_FIELD(_mem, _field) ((_mem[0] == _field[0]) && (_mem[1] == _field[1])) #define CHECK_HEADER_FIELD(_mem, _field) ((_mem[0] == _field[0]) && (_mem[1] == _field[1]))
#define CHECK_HEADER_FIELD_BMP(_mem) \ #define CHECK_HEADER_FIELD_BMP(_mem) \
(CHECK_HEADER_FIELD(_mem, "BM") || CHECK_HEADER_FIELD(_mem, "BA") || \ (CHECK_HEADER_FIELD(_mem, "BM") || CHECK_HEADER_FIELD(_mem, "BA") || \
CHECK_HEADER_FIELD(_mem, "CI") || CHECK_HEADER_FIELD(_mem, "CP") || \ CHECK_HEADER_FIELD(_mem, "CI") || CHECK_HEADER_FIELD(_mem, "CP") || \
CHECK_HEADER_FIELD(_mem, "IC") || CHECK_HEADER_FIELD(_mem, "PT")) CHECK_HEADER_FIELD(_mem, "IC") || CHECK_HEADER_FIELD(_mem, "PT"))
static bool checkbmp(const uchar *mem, const size_t size) static bool checkbmp(const uchar *mem, const size_t size)
{ {
if (size < BMP_FILEHEADER_SIZE) { if (size < (BMP_FILEHEADER_SIZE + sizeof(BMPINFOHEADER))) {
return false; return false;
} }
if (!CHECK_HEADER_FIELD_BMP(mem)) { if (!CHECK_HEADER_FIELD_BMP(mem)) {
return false; return false;
} }
bool ok = false; bool ok = false;
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bool imb_is_a_bmp(const uchar *buf, size_t size) bool imb_is_a_bmp(const uchar *buf, size_t size)
{ {
return checkbmp(buf, size); return checkbmp(buf, size);
} }
static size_t imb_bmp_calc_row_size_in_bytes(size_t x, size_t depth) static size_t imb_bmp_calc_row_size_in_bytes(size_t x, size_t depth)
{ {
if (depth <= 8) { /* https://docs.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-bitmapinfoheader#calculating-surface-stride
return (depth * x + 31) / 32 * 4; */
} return (((x * depth) + 31) & ~31) >> 3;
return (depth >> 3) * x;
} }
ImBuf *imb_bmp_decode(const uchar *mem, size_t size, int flags, char colorspace[IM_MAX_SPACE]) ImBuf *imb_bmp_decode(const uchar *mem, size_t size, int flags, char colorspace[IM_MAX_SPACE])
{ {
ImBuf *ibuf = NULL; ImBuf *ibuf = NULL;
BMPINFOHEADER bmi; BMPINFOHEADER bmi;
int x, y, depth, ibuf_depth, skip; int ibuf_depth;
const uchar *bmp; const uchar *bmp;
uchar *rect; uchar *rect;
ushort col; ushort col;
double xppm, yppm;
bool top_to_bottom = false; bool top_to_bottom = false;
(void)size; /* unused */
if (checkbmp(mem, size) == 0) { if (checkbmp(mem, size) == 0) {
return NULL; return NULL;
} }
colorspace_set_default_role(colorspace, IM_MAX_SPACE, COLOR_ROLE_DEFAULT_BYTE); colorspace_set_default_role(colorspace, IM_MAX_SPACE, COLOR_ROLE_DEFAULT_BYTE);
const size_t pixel_data_offset = LITTLE_LONG(*(int *)(mem + 10)); /* For systems where an int needs to be 4 bytes aligned. */
bmp = mem + pixel_data_offset; memcpy(&bmi, mem + BMP_FILEHEADER_SIZE, sizeof(bmi));
if (CHECK_HEADER_FIELD_BMP(mem)) { const size_t palette_offset = (size_t)BMP_FILEHEADER_SIZE + LITTLE_LONG(bmi.biSize);
/* skip fileheader */ const int depth = LITTLE_SHORT(bmi.biBitCount);
mem += BMP_FILEHEADER_SIZE; const int xppm = LITTLE_LONG(bmi.biXPelsPerMeter);
const int yppm = LITTLE_LONG(bmi.biYPelsPerMeter);
const int x = LITTLE_LONG(bmi.biWidth);
int y = LITTLE_LONG(bmi.biHeight);
/* Negative height means bitmap is stored top-to-bottom. */
if (y < 0) {
y = -y;
top_to_bottom = true;
} }
else {
/* Validate and cross-check offsets and sizes. */
if (x < 1 ||
!(depth == 1 || depth == 4 || depth == 8 || depth == 16 || depth == 24 || depth == 32)) {
return NULL; return NULL;
} }
/* for systems where an int needs to be 4 bytes aligned */ const size_t pixel_data_offset = (size_t)LITTLE_LONG(*(int *)(mem + 10));
memcpy(&bmi, mem, sizeof(bmi)); const size_t header_bytes = BMP_FILEHEADER_SIZE + sizeof(BMPINFOHEADER);
const size_t num_actual_data_bytes = size - pixel_data_offset;
skip = LITTLE_LONG(bmi.biSize);
x = LITTLE_LONG(bmi.biWidth);
y = LITTLE_LONG(bmi.biHeight);
depth = LITTLE_SHORT(bmi.biBitCount);
xppm = LITTLE_LONG(bmi.biXPelsPerMeter);
yppm = LITTLE_LONG(bmi.biYPelsPerMeter);
const size_t row_size_in_bytes = imb_bmp_calc_row_size_in_bytes(x, depth); const size_t row_size_in_bytes = imb_bmp_calc_row_size_in_bytes(x, depth);
const size_t num_expected_data_bytes = row_size_in_bytes * y; const size_t num_expected_data_bytes = row_size_in_bytes * y;
const size_t num_actual_data_bytes = size - pixel_data_offset; if (num_actual_data_bytes < num_expected_data_bytes || num_actual_data_bytes > size ||
if (num_actual_data_bytes < num_expected_data_bytes) { pixel_data_offset < header_bytes || pixel_data_offset > (size - num_expected_data_bytes) ||
palette_offset < header_bytes || palette_offset > pixel_data_offset) {
return NULL; return NULL;
} }
if (depth <= 8) { if (depth <= 8) {
ibuf_depth = 24; ibuf_depth = 24;
} }
else { else {
ibuf_depth = depth; ibuf_depth = depth;
} }
if (y < 0) { bmp = mem + pixel_data_offset;
/* Negative height means bitmap is stored top-to-bottom... */
y = -y;
top_to_bottom = true;
}
#if 0 #if 0
printf("skip: %d, x: %d y: %d, depth: %d (%x)\n", skip, x, y, depth, bmi.biBitCount); printf("palette_offset: %d, x: %d y: %d, depth: %d\n", palette_offset, x, y, depth);
#endif #endif
if (flags & IB_test) { if (flags & IB_test) {
ibuf = IMB_allocImBuf(x, y, ibuf_depth, 0); ibuf = IMB_allocImBuf(x, y, ibuf_depth, 0);
} }
else { else {
ibuf = IMB_allocImBuf(x, y, ibuf_depth, IB_rect); ibuf = IMB_allocImBuf(x, y, ibuf_depth, IB_rect);
if (!ibuf) { if (!ibuf) {
return NULL; return NULL;
} }
rect = (uchar *)ibuf->rect; rect = (uchar *)ibuf->rect;
if (depth <= 8) { if (depth <= 8) {
const char(*palette)[4] = (void *)(mem + skip); const char(*palette)[4] = (const char(*)[4])(mem + palette_offset);
const int startmask = ((1 << depth) - 1) << 8; const int startmask = ((1 << depth) - 1) << 8;
for (size_t i = y; i > 0; i--) { for (size_t i = y; i > 0; i--) {
int index; int index;
int bitoffs = 8; int bitoffs = 8;
int bitmask = startmask; int bitmask = startmask;
int nbytes = 0; int nbytes = 0;
const char *pcol; const char *pcol;
if (top_to_bottom) { if (top_to_bottom) {
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