[gtk/matthiasc/color-profile-rebased: 4/22] gsk: Linearize colors too

[Matthias Clasen <matthiasc src gnome org>]

commit b5981f82d604e345d8ddbdf0f472b9b13640a7f1
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun May 8 13:19:59 2022 -0400

    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 5cfa7863ba..51c042472a 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/gdkcolorspaceprivate.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_space_get_srgb_linear (),
+                      (guchar *) rgba,
+                      sizeof (float) * 4,
+                      GDK_MEMORY_R32G32B32A32_FLOAT,
+                      gdk_color_space_get_srgb (),
+                      1,
+                      1);
+  float_to_half4 ((const float *)&d, h);
 }
 
 /* fill_vertex_data */