[plasma/kwin] src/opengl: opengl/colormanagement: correct ictcp inverse

Git commit a9495061163e5434dc76be40c081ba1dd7ca4d91 by Vlad Zahorodnii, on behalf of Christopher Snowhill.
Committed on 22/07/2026 at 10:18.
Pushed by vladz into branch 'master'.

opengl/colormanagement: correct ictcp inverse

This transcription error was found by static analysis and fresh
calculation of the inverse matrix. One number missing a single zero,
and two numbers I corrected just for the sake of it, due to their
respective fields being shortened by two decimal places compared to
their inverse columns.

Unlikely to cause a major difference, though.

Fixes e2186eb838fba8640003020774a1e1052c2d92e9 - wow, it took two
years for anything to catch this. Looks like Clutter also took the
same math verbatim, so they get a MR too.

M  +3    -3    src/opengl/colormanagement.glsl

https://invent.kde.org/plasma/kwin/-/commit/a9495061163e5434dc76be40c081ba1dd7ca4d91

diff --git a/src/opengl/colormanagement.glsl b/src/opengl/colormanagement.glsl
index d0a87e0f366..96f926b6be3 100644
--- a/src/opengl/colormanagement.glsl
+++ b/src/opengl/colormanagement.glsl
@@ -101,9 +101,9 @@ const mat3 toICtCp = mat3(
     0.0,  1.709716796875, -0.132568359375
 );
 const mat3 fromICtCp = mat3(
-    1.0,               1.0,             1.0,
-    0.00860903703793, -0.008609037037,  0.56031335710680,
-    0.11102962500303, -0.111029625003, -0.32062717498732
+    1.0,               1.0,               1.0,
+    0.00860903703793, -0.00860903703793,  0.56003133571068,
+    0.11102962500303, -0.11102962500303, -0.32062717498732
 );
 
 vec3 doTonemapping(vec3 color) {