From c4a5b72a5fcfbc7fcfbf90c17dfeb15c96b3fedd Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Sun, 8 May 2022 13:19:59 -0400
Subject: [PATCH] gsk: Linearize colors too

Convert all the GdkRGBA colors that we have
in render nodes to linear sRGB before using
them. This brings the rendering back in line
with what cairo produces, except for the video.
---
 gsk/gl/gskglrenderjob.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/gsk/gl/gskglrenderjob.c b/gsk/gl/gskglrenderjob.c
index 19768662d7..0461cb8899 100644
--- a/gsk/gl/gskglrenderjob.c
+++ b/gsk/gl/gskglrenderjob.c
@@ -27,6 +27,7 @@
 #include <gdk/gdkprofilerprivate.h>
 #include <gdk/gdkrgbaprivate.h>
 #include <gdk/gdkcolorprofileprivate.h>
+#include <gdk/gdkmemoryformatprivate.h>
 #include <gsk/gskrendernodeprivate.h>
 #include <gsk/gskglshaderprivate.h>
 #include <gdk/gdktextureprivate.h>
@@ -989,11 +990,23 @@ gsk_gl_render_job_update_clip (GskGLRenderJob        *job,
   return TRUE;
 }
 
+/* Convert from sRGB floats to linear sRGB half-floats */
 static inline void
 rgba_to_half (const GdkRGBA *rgba,
               guint16        h[4])
 {
-  float_to_half4 ((const float *)rgba, h);
+  GdkRGBA d;
+  gdk_memory_convert ((guchar *) &d,
+                      sizeof (float) * 4,
+                      GDK_MEMORY_R32G32B32A32_FLOAT,
+                      gdk_color_profile_get_srgb_linear (),
+                      (guchar *) rgba,
+                      sizeof (float) * 4,
+                      GDK_MEMORY_R32G32B32A32_FLOAT,
+                      gdk_color_profile_get_srgb (),
+                      1,
+                      1);
+  float_to_half4 ((const float *)&d, h);
 }
 
 /* fill_vertex_data */