From: Øyvind Kolås <pippin@gimp.org>
Date: Tue, 2 May 2023 20:55:55 +0000 (+0200)
Subject: LUT: speed up 3bpp->4bpp LUT
X-Git-Tag: archive/raspbian/1%0.1.106-3+rpi1^2~15^2^2~1
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=bea667f8a1b9a4f2c8f966bf2c4754824fa0f47c;p=babl.git

LUT: speed up 3bpp->4bpp LUT

Keep alpha (0xff) as computed rather than stripping and reapplying.
---

diff --git a/babl/babl-fish-path.c b/babl/babl-fish-path.c
index afb3a79..712f57a 100644
--- a/babl/babl-fish-path.c
+++ b/babl/babl-fish-path.c
@@ -276,8 +276,7 @@ static inline int _do_lut (uint32_t *lut,
           uint32_t *dst = (uint32_t*)destination;
           while (n--)
           {
-             uint32_t col = src[0]*256*256+src[1]*256+src[2];
-             *dst = lut[col] | 0xff000000;
+             *dst = lut[src[0]*256*256+src[1]*256+src[2]];
              dst++;
              src+=3;
           }
@@ -455,8 +454,6 @@ static inline int babl_fish_lut_process_maybe (const Babl *babl,
                                   temp_lut, 3,
                                   lut, 4,
                                   256*256*256);
-         for (int o = 0; o < 256 * 256 * 256; o++)
-           lut[o] = lut[o] & 0x00ffffff;
          free (temp_lut);
        }
        else if (source_bpp == 2 && dest_bpp == 2)