diff options
| author | Robin Watts <Robin.Watts@artifex.com> | 2020-03-02 17:10:43 +0000 |
|---|---|---|
| committer | Chris Liddell <chris.liddell@artifex.com> | 2020-03-10 13:06:12 +0000 |
| commit | 15f5f8bad503e9d3e63db9c3ca395deffd6b1e20 (patch) | |
| tree | 15a8edaa2b63e5fe3cb50ba33879f53d86143a15 | |
| parent | d5809b79052b20c723700cce75e7e1543a3ddc23 (diff) | |
| download | ghostpdl-15f5f8bad503e9d3e63db9c3ca395deffd6b1e20.tar.gz | |
Fix 16bit blending problem.
Seen with:
gs -sDEVICE=psdcmyk16 -o out%d.psd -r72 -dMaxBitmap=2000M
tests_private/pdf/forms/v1.5/proxy_vol_1_number_1_1.pdf
on page 3.
| -rw-r--r-- | base/gxblend.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/base/gxblend.c b/base/gxblend.c index 4f0d3a0c5..8e8068886 100644 --- a/base/gxblend.c +++ b/base/gxblend.c @@ -2193,7 +2193,6 @@ art_pdf_recomposite_group_16(uint16_t *gs_restrict *dstp, uint16_t *gs_restrict uint16_t dst_alpha; int i; uint32_t tmp; - int scale; uint16_t *gs_restrict dst = *dstp; if (src_alpha_g == 0) @@ -2219,21 +2218,24 @@ art_pdf_recomposite_group_16(uint16_t *gs_restrict *dstp, uint16_t *gs_restrict if (src_alpha_g != 65535 && dst_alpha != 0) { /* Uncomposite the color. In other words, solve "src = (src, src_alpha_g) over dst" for src */ - scale = ((unsigned int)(dst_alpha * 65535 + (src_alpha_g>>1))) / src_alpha_g - + uint32_t scale = ((unsigned int)(dst_alpha * 65535 + (src_alpha_g>>1))) / src_alpha_g - dst_alpha; /* scale is NOT in 16.16 form here. I've seen values of 0xfefe01, for example. */ for (i = 0; i < n_chan; i++) { int si, di; int64_t tmp64; + int t; si = src[i]; di = dst[i]; /* RJW: Nasty that we have to resort to 64bit here, but we'll live with it. */ - tmp64 = (si - di) * (int64_t)scale + 0x8000; - tmp = si + (tmp64 >> 16); - if (tmp > 65535) - tmp = 65535; - src[i] = tmp; + tmp64 = (si - di) * (uint64_t)scale + 0x8000; + t = si + (tmp64 >> 16); + if (t < 0) + t = 0; + else if (t > 65535) + t = 65535; + src[i] = t; } } |