[gnome-photos] gegl: Disable OpenCL

[Debarshi Ray <debarshir src gnome org>]

commit 41ffa2ed91d47a2f04d3ff92cc306a6329655007
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu Nov 2 09:26:48 2017 +0100

    gegl: Disable OpenCL
    
    The OpenCL code paths are not that well tested across multiple GPU
    drivers, and can generate faulty output. Moreover, until there's
    OpenCL coverage for all the operations that are used it's not going to
    have the expected performance boost due to memory transfers between
    the CPU and GPU. In fact, today, for many cases using the GPU is
    measurably, sometimes significantly so, slower than the CPU.

 src/photos-gegl.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/photos-gegl.c b/src/photos-gegl.c
index 2110561..6ccaec3 100644
--- a/src/photos-gegl.c
+++ b/src/photos-gegl.c
@@ -311,6 +311,7 @@ photos_gegl_init (void)
 
   config = gegl_config ();
   g_object_set (config, "threads", threads, NULL);
+  g_object_set (config, "use-opencl", FALSE, NULL);
 }