[gimp] app: gimp:desaturate, improve indentation and reduce overhead

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

commit 5428e5e384f272269de0892d2ea0a65e02821ced
Author: Øyvind Kolås <pippin gimp org>
Date:   Thu Jun 6 15:07:15 2019 +0200

    app: gimp:desaturate, improve indentation and reduce overhead
    
    Fetch the red, green and blue luminance factors only in the desaturate
    modes that use them.

 app/operations/gimpoperationdesaturate.c | 35 ++++++++++++++++----------------
 1 file changed, 18 insertions(+), 17 deletions(-)
---
diff --git a/app/operations/gimpoperationdesaturate.c b/app/operations/gimpoperationdesaturate.c
index e7cc2d2e5a..b9353e6c54 100644
--- a/app/operations/gimpoperationdesaturate.c
+++ b/app/operations/gimpoperationdesaturate.c
@@ -167,12 +167,8 @@ gimp_operation_desaturate_process (GeglOperation       *operation,
                                    gint                 level)
 {
   GimpOperationDesaturate *desaturate = GIMP_OPERATION_DESATURATE (operation);
-  
   gfloat                  *src        = in_buf;
   gfloat                  *dest       = out_buf;
-  double red_luminance, green_luminance, blue_luminance;
-  const Babl *space = gegl_operation_get_source_space (operation, "input");
-  babl_space_get_rgb_luminance (space, &red_luminance, &green_luminance, &blue_luminance);
 
   switch (desaturate->mode)
     {
@@ -203,19 +199,24 @@ gimp_operation_desaturate_process (GeglOperation       *operation,
 
     case GIMP_DESATURATE_LUMA:
     case GIMP_DESATURATE_LUMINANCE:
-      while (samples--)
-        {
-          gfloat value  = (src[0] * red_luminance) +
-                          (src[1] * green_luminance) +
-                          (src[2] * blue_luminance);
-          dest[0] = value;
-          dest[1] = value;
-          dest[2] = value;
-          dest[3] = src[3];
-
-          src  += 4;
-          dest += 4;
-        }
+      {
+        const Babl *space = gegl_operation_get_source_space (operation, "input");
+        double red_luminance, green_luminance, blue_luminance;
+        babl_space_get_rgb_luminance (space, &red_luminance, &green_luminance, &blue_luminance);
+        while (samples--)
+          {
+            gfloat value  = (src[0] * red_luminance)   +
+                            (src[1] * green_luminance) +
+                            (src[2] * blue_luminance);
+            dest[0] = value;
+            dest[1] = value;
+            dest[2] = value;
+            dest[3] = src[3];
+
+            src  += 4;
+            dest += 4;
+          }
+      }
       break;
 
     case GIMP_DESATURATE_AVERAGE: