From 997ec3e829d4849d350fda9ac7f5ac1f7c50236c Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pekka.paalanen@collabora.com>
Date: Tue, 13 Dec 2022 15:10:32 +0200
Subject: [PATCH] color: reword set_tf_gamma

Improve the definition and do not talk about gamma. Gamma is still in
the name, but maybe that's fine.

Change the encoding to support three decimals, I think that's well
enough.

Set some limits on the exponent so that compositor implementations do
not get into trouble with nonsense values.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
---
 staging/color-management/color-management-v1.xml | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/staging/color-management/color-management-v1.xml b/staging/color-management/color-management-v1.xml
index 6355f47..89d766e 100644
--- a/staging/color-management/color-management-v1.xml
+++ b/staging/color-management/color-management-v1.xml
@@ -509,13 +509,19 @@
     </request>
 
     <request name="set_tf_gamma">
-      <description summary="Set the Gamma curve">
-        Sets the transfer characteristics as a gamma curve.
+      <description summary="transfer characteristic as a power curve">
+        Sets the transfer characteristic to a power curve with the given
+        exponent. This curve represents the conversion from electrical to
+        optical pixel or color values.
 
-        Use decimal value to define the gamma (e.g. 22 for a 2.2 Gamma, 24 for a 2.4 Gamma, etc)
+        The curve exponent shall be multiplied by 10000 to get the argument
+        eexp value to carry precision of 4 decimals.
+
+        The curve exponent must be at least 1.0 and at most 10.0. Otherwise
+        the protocol error invalid_tf is raised.
       </description>
 
-      <arg name="gamma" type="uint" summary="The gamma type (2.2, 2.4 etc)"/>
+      <arg name="eexp" type="uint" summary="the exponent * 10000"/>
     </request>
 
     <request name="set_primaries_cicp">