[gegl] Fix contrast boost in negative-darkroom

[Øyvind "pippin" Kolås <ok src gnome org>]

commit ed669b4cc835a4f575045a21c5426729df87a1c9
Author: JonnyRobbie <marcodv seznam cz>
Date:   Sun Jul 18 00:05:07 2021 +0200

    Fix contrast boost in negative-darkroom

 operations/common/negative-darkroom.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/operations/common/negative-darkroom.c b/operations/common/negative-darkroom.c
index 0086c567e..63faede5c 100644
--- a/operations/common/negative-darkroom.c
+++ b/operations/common/negative-darkroom.c
@@ -315,6 +315,11 @@ process (GeglOperation       *operation,
                b = log10(b);
                /*printf("Logarithmic RGB intensity %f %f %f\n", r, g, b);*/
 
+               // Adjust contrast
+               r = (r - rMid) * o->contrast + rMid;
+               g = (g - gMid) * o->contrast + gMid;
+               b = (b - bMid) * o->contrast + bMid;
+
                // Apply the DH curve
                r = curve_lerp(curves[o->curve].rx,
                               curves[o->curve].ry,
@@ -341,11 +346,6 @@ process (GeglOperation       *operation,
                b -= Dfogy;
                /*printf("Adjusted RGB density %f %f %f\n", r, g, b);*/
 
-               // Adjust contrast
-               r = (r - rMid) * o->contrast + rMid;
-               g = (g - gMid) * o->contrast + gMid;
-               b = (b - bMid) * o->contrast + bMid;
-
                // Simulate dye density with exponentiation to get
                // the CIEXYZ transmittance back
                out[0] = pow(10, -(r * curves[o->curve].cdens.X +