https://git.reactos.org/?p=reactos.git;a=commitdiff;h=968c8f37f14cf90fba994082274671b85f14764e
commit 968c8f37f14cf90fba994082274671b85f14764e
Author: Katayama Hirofumi MZ <katayama.hirofumi...@gmail.com>
AuthorDate: Tue Dec 25 18:04:21 2018 +0900
Commit: GitHub <nore...@github.com>
CommitDate: Tue Dec 25 18:04:21 2018 +0900
[WIN32SS] Fix RLE4 bitmap decoding (#1188)
CORE-10553, CORE-11399
---
win32ss/gdi/eng/rlecomp.c | 73 +++++++++++++++++++++++++++++++++--------------
1 file changed, 51 insertions(+), 22 deletions(-)
diff --git a/win32ss/gdi/eng/rlecomp.c b/win32ss/gdi/eng/rlecomp.c
index ea90c4219b..50f5e911ab 100644
--- a/win32ss/gdi/eng/rlecomp.c
+++ b/win32ss/gdi/eng/rlecomp.c
@@ -18,40 +18,52 @@ enum Rle_EscapeCodes
RLE_DELTA = 2 /* Delta */
};
-VOID DecompressBitmap(SIZEL Size, BYTE *CompressedBits, BYTE
*UncompressedBits, LONG Delta, ULONG Format, ULONG cjSizeImage)
+VOID DecompressBitmap(SIZEL Size, BYTE *CompressedBits, BYTE *UncompressedBits,
+ LONG Delta, ULONG Format, ULONG cjSizeImage)
{
- INT x = 0;
- INT y = Size.cy - 1;
- INT c;
- INT length;
- INT width;
- INT height = y;
+ INT x = 0, y = Size.cy - 1;
+ INT i, c, c2, length;
+ INT width = Size.cx, height = y;
BYTE *begin = CompressedBits;
BYTE *bits = CompressedBits;
BYTE *temp;
- INT shift = 0;
+ BOOL is4bpp = FALSE;
if ((Format == BMF_4RLE) || (Format == BMF_4BPP))
- shift = 1;
+ is4bpp = TRUE;
else if ((Format != BMF_8RLE) && (Format != BMF_8BPP))
return;
- width = ((Size.cx + shift) >> shift);
-
_SEH2_TRY
{
while (y >= 0 && (bits - begin) <= cjSizeImage)
{
- length = (*bits++) >> shift;
+ length = *bits++;
if (length)
{
c = *bits++;
- while (length--)
+ for (i = 0; i < length; i++)
{
if (x >= width) break;
- temp = UncompressedBits + (((height - y) * Delta) + x);
+ temp = UncompressedBits + (height - y) * Delta;
+ if (is4bpp)
+ {
+ temp += x / 2;
+ if (i & 1)
+ c2 = c & 0x0F;
+ else
+ c2 = c >> 4;
+ if (x & 1)
+ *temp |= c2;
+ else
+ *temp |= c2 << 4;
+ }
+ else
+ {
+ temp += x;
+ *temp = c;
+ }
x++;
- *temp = c;
}
}
else
@@ -66,19 +78,36 @@ VOID DecompressBitmap(SIZEL Size, BYTE *CompressedBits,
BYTE *UncompressedBits,
case RLE_END:
_SEH2_YIELD(return);
case RLE_DELTA:
- x += (*bits++) >> shift;
- y -= (*bits++) >> shift;
+ x += *bits++;
+ y -= *bits++;
break;
default:
- length = length >> shift;
- while (length--)
+ for (i = 0; i < length; i++)
{
- c = *bits++;
+ if (!(is4bpp && i & 1))
+ c = *bits++;
+
if (x < width)
{
- temp = UncompressedBits + (((height - y) * Delta)
+ x);
+ temp = UncompressedBits + (height - y) * Delta;
+ if (is4bpp)
+ {
+ temp += x / 2;
+ if (i & 1)
+ c2 = c & 0x0F;
+ else
+ c2 = c >> 4;
+ if (x & 1)
+ *temp |= c2;
+ else
+ *temp |= c2 << 4;
+ }
+ else
+ {
+ temp += x;
+ *temp = c;
+ }
x++;
- *temp = c;
}
}
if ((bits - begin) & 1)
