diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/mupdf/fitz/math.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/mupdf/fitz/math.h b/include/mupdf/fitz/math.h index 9ba79697..5e25f871 100644 --- a/include/mupdf/fitz/math.h +++ b/include/mupdf/fitz/math.h @@ -19,6 +19,11 @@ static inline int fz_mul255(int a, int b) * to give a single value in the same range as A was. */ #define FZ_COMBINE(A,B) (((A)*(B))>>8) +/* Combine values A (in the 0..255 range) and B (in the 0..256 range), + * then reverse it within that range to give a single value in the + * 0..256 range. */ +#define FZ_REVERSE_COMBINE(A,B) ((0xFF00 - (A)*(B))>>8) + /* Combine values A and C (in the same (any) range) and B and D (in the * 0..256 range), to give a single value in the same range as A and C were. */ #define FZ_COMBINE2(A,B,C,D) (FZ_COMBINE((A), (B)) + FZ_COMBINE((C), (D))) |