diff options
Diffstat (limited to 'fitz/filt_predict.c')
| -rw-r--r-- | fitz/filt_predict.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/fitz/filt_predict.c b/fitz/filt_predict.c index 1501fc09..94f2718a 100644 --- a/fitz/filt_predict.c +++ b/fitz/filt_predict.c @@ -23,33 +23,31 @@ struct fz_predict_s unsigned char *rp, *wp; }; -static inline int -getcomponent(unsigned char *buf, int x, int bpc) +static inline int getcomponent(unsigned char *line, int x, int bpc) { switch (bpc) { - case 1: return buf[x / 8] >> (7 - (x % 8)) & 0x01; - case 2: return buf[x / 4] >> ((3 - (x % 4)) * 2) & 0x03; - case 4: return buf[x / 2] >> ((1 - (x % 2)) * 4) & 0x0f; - case 8: return buf[x]; + case 1: return (line[x >> 3] >> ( 7 - (x & 7) ) ) & 1; + case 2: return (line[x >> 2] >> ( ( 3 - (x & 3) ) << 1 ) ) & 3; + case 4: return (line[x >> 1] >> ( ( 1 - (x & 1) ) << 2 ) ) & 15; + case 8: return line[x]; } return 0; } -static inline void -putcomponent(unsigned char *buf, int x, int bpc, int value) + +static inline void putcomponent(unsigned char *buf, int x, int bpc, int value) { switch (bpc) { - case 1: buf[x / 8] |= value << (7 - (x % 8)); break; - case 2: buf[x / 4] |= value << ((3 - (x % 4)) * 2); break; - case 4: buf[x / 2] |= value << ((1 - (x % 2)) * 4); break; + case 1: buf[x >> 3] |= value << (7 - (x & 7)); break; + case 2: buf[x >> 2] |= value << ((3 - (x & 3)) << 1); break; + case 4: buf[x >> 1] |= value << ((1 - (x & 1)) << 2); break; case 8: buf[x] = value; break; } } -static inline int -paeth(int a, int b, int c) +static inline int paeth(int a, int b, int c) { /* The definitions of ac and bc are correct, not a typo. */ int ac = b - c, bc = a - c, abcc = ac + bc; |