[shotwell] libraw.vapi: Set the correct power value for the gamma curve

[Jens Georg <jensgeorg src gnome org>]

commit e045b9b48851dd4f21387e99de1aa3a1e10a3a66
Author: Debarshi Ray <debarshir gnome org>
Date:   Sat Feb 4 16:21:17 2017 +0100

    libraw.vapi: Set the correct power value for the gamma curve
    
    libraw_output_params_t.gamm[0] is meant to have the inverted gamma or
    power value. See:
    http://www.libraw.org/docs/API-datastruct-eng.html#libraw_output_params_t
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778174

 vapi/libraw.vapi |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/vapi/libraw.vapi b/vapi/libraw.vapi
index da6a57e..5ec2e4e 100644
--- a/vapi/libraw.vapi
+++ b/vapi/libraw.vapi
@@ -150,7 +150,7 @@ public struct OutputParams {
     }
     
     public void set_gamma_curve(double power, double slope) {
-        gamm[0] = power;
+        gamm[0] = 1.0 / power;
         gamm[1] = slope;
     }
 }