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| author | Robin Watts <robin.watts@artifex.com> | 2016-03-22 19:04:34 +0000 |
|---|---|---|
| committer | Robin Watts <robin.watts@artifex.com> | 2016-03-22 19:05:33 +0000 |
| commit | 28fd7f229953c34e5764b5d15eff32e7c0360cdb (patch) | |
| tree | 1a34d8ade42cc660bfed3c81ce0407768636f391 | |
| parent | c38d88673c87b373e6913b16ddd7444da062dcf9 (diff) | |
| download | mupdf-28fd7f229953c34e5764b5d15eff32e7c0360cdb.tar.xz | |
Optimise the C for do_threshold_1.
Simple unrolling.
| -rw-r--r-- | source/fitz/halftone.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/source/fitz/halftone.c b/source/fitz/halftone.c index 27dc3db1..0a53fbb3 100644 --- a/source/fitz/halftone.c +++ b/source/fitz/halftone.c @@ -150,6 +150,57 @@ static void make_ht_line(unsigned char *buf, fz_halftone *ht, int x, int y, int /* Inner mono thresholding code */ typedef void (threshold_fn)(unsigned char *ht_line, unsigned char *pixmap, unsigned char *out, int w); +#if 1 +static void do_threshold_1(unsigned char *ht_line, unsigned char *pixmap, unsigned char *out, int w) +{ + int h; + + w -= 7; + while (w > 0) + { + h = 0; + if (pixmap[0] < ht_line[0]) + h |= 0x80; + if (pixmap[2] < ht_line[1]) + h |= 0x40; + if (pixmap[4] < ht_line[2]) + h |= 0x20; + if (pixmap[6] < ht_line[3]) + h |= 0x10; + if (pixmap[8] < ht_line[4]) + h |= 0x08; + if (pixmap[10] < ht_line[5]) + h |= 0x04; + if (pixmap[12] < ht_line[6]) + h |= 0x02; + if (pixmap[14] < ht_line[7]) + h |= 0x01; + pixmap += 16; /* Skip the alpha */ + ht_line += 8; + *out++ = h; + w -= 8; + } + if (w > -7) + { + h = 0; + if (pixmap[0] < ht_line[0]) + h |= 0x80; + if (w > -6 && pixmap[2] < ht_line[1]) + h |= 0x40; + if (w > -5 && pixmap[4] < ht_line[2]) + h |= 0x20; + if (w > -4 && pixmap[6] < ht_line[3]) + h |= 0x10; + if (w > -3 && pixmap[8] < ht_line[4]) + h |= 0x08; + if (w > -2 && pixmap[10] < ht_line[5]) + h |= 0x04; + if (w > -1 && pixmap[12] < ht_line[6]) + h |= 0x02; + *out++ = h; + } +} +#else static void do_threshold_1(unsigned char *ht_line, unsigned char *pixmap, unsigned char *out, int w) { int bit = 0x80; @@ -173,6 +224,7 @@ static void do_threshold_1(unsigned char *ht_line, unsigned char *pixmap, unsign if (bit != 0x80) *out = h; } +#endif /* Note that the tests in do_threshold_4 are inverted compared to those |