[gtk/wip/otte/color-profiles: 3/4] ngl: Linearize colors too

[Matthias Clasen <matthiasc src gnome org>]

commit 1be2d6fa7f09a5d6e4fe406942387c8e30988b7d
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Sep 30 07:24:28 2021 -0400

    ngl: 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/ngl/gsknglrenderjob.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
---
diff --git a/gsk/ngl/gsknglrenderjob.c b/gsk/ngl/gsknglrenderjob.c
index f882a3e8ee..4582ad06c3 100644
--- a/gsk/ngl/gsknglrenderjob.c
+++ b/gsk/ngl/gsknglrenderjob.c
@@ -30,6 +30,7 @@
 #include <gsk/gskglshaderprivate.h>
 #include <gdk/gdktextureprivate.h>
 #include <gdk/gdkcolorprofileprivate.h>
+#include <gdk/gdkmemoryformatprivate.h>
 #include <gsk/gsktransformprivate.h>
 #include <gsk/gskroundedrectprivate.h>
 #include <math.h>
@@ -925,11 +926,24 @@ gsk_ngl_render_job_update_clip (GskNglRenderJob       *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_R32G32B32_FLOAT,
+                      gdk_color_profile_get_srgb_linear (),
+                      (guchar *) rgba,
+                      sizeof (float) * 4,
+                      GDK_MEMORY_R32G32B32_FLOAT,
+                      gdk_color_profile_get_srgb (),
+                      1,
+                      1);
+  d.alpha = rgba->alpha;
+  float_to_half4 ((const float *)&d, h);
 }
 
 /* fill_vertex_data */