From 2d6040e2a38cdada9229916e15437279df06dda4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 18 Sep 2019 16:18:58 +0200
Subject: [PATCH] wayland/shm: Advertise support for RGB565

Doesn't hurt to support it, could save memory bandwidth would any client
use it without degrading visual quality.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/804
---
 src/wayland/meta-wayland-buffer.c | 21 +++++++++++++++++++++
 src/wayland/meta-wayland-buffer.h |  2 ++
 src/wayland/meta-wayland.c        |  3 ++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/wayland/meta-wayland-buffer.c b/src/wayland/meta-wayland-buffer.c
index cbf48727d..60ef78cd1 100644
--- a/src/wayland/meta-wayland-buffer.c
+++ b/src/wayland/meta-wayland-buffer.c
@@ -57,6 +57,7 @@
 #include "cogl/cogl-egl.h"
 #include "meta/util.h"
 #include "wayland/meta-wayland-dma-buf.h"
+#include "wayland/meta-wayland-private.h"
 
 #ifdef HAVE_NATIVE_BACKEND
 #include "backends/native/meta-drm-buffer-gbm.h"
@@ -205,6 +206,10 @@ shm_format_to_cogl_pixel_format (enum wl_shm_format     shm_format,
       components = COGL_TEXTURE_COMPONENTS_RGB;
       break;
 #elif G_BYTE_ORDER == G_LITTLE_ENDIAN
+    case WL_SHM_FORMAT_RGB565:
+      format = COGL_PIXEL_FORMAT_RGB_565;
+      components = COGL_TEXTURE_COMPONENTS_RGB;
+      break;
     case WL_SHM_FORMAT_ARGB8888:
       format = COGL_PIXEL_FORMAT_BGRA_8888_PRE;
       break;
@@ -736,3 +741,19 @@ meta_wayland_buffer_class_init (MetaWaylandBufferClass *klass)
                                               NULL, NULL, NULL,
                                               G_TYPE_NONE, 0);
 }
+
+void
+meta_wayland_init_shm (MetaWaylandCompositor *compositor)
+{
+  static const enum wl_shm_format shm_formats[] = {
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+    WL_SHM_FORMAT_RGB565,
+#endif
+  };
+  int i;
+
+  wl_display_init_shm (compositor->wayland_display);
+
+  for (i = 0; i < G_N_ELEMENTS (shm_formats); i++)
+    wl_display_add_shm_format (compositor->wayland_display, shm_formats[i]);
+}
diff --git a/src/wayland/meta-wayland-buffer.h b/src/wayland/meta-wayland-buffer.h
index 77e68e724..e00406ba2 100644
--- a/src/wayland/meta-wayland-buffer.h
+++ b/src/wayland/meta-wayland-buffer.h
@@ -91,4 +91,6 @@ void                    meta_wayland_buffer_process_damage      (MetaWaylandBuff
 CoglScanout *           meta_wayland_buffer_try_acquire_scanout (MetaWaylandBuffer     *buffer,
                                                                  CoglOnscreen          *onscreen);
 
+void meta_wayland_init_shm (MetaWaylandCompositor *compositor);
+
 #endif /* META_WAYLAND_BUFFER_H */
diff --git a/src/wayland/meta-wayland.c b/src/wayland/meta-wayland.c
index 1feddef93..c0d3197af 100644
--- a/src/wayland/meta-wayland.c
+++ b/src/wayland/meta-wayland.c
@@ -31,6 +31,7 @@
 #include "clutter/clutter.h"
 #include "clutter/wayland/clutter-wayland-compositor.h"
 #include "core/main-private.h"
+#include "wayland/meta-wayland-buffer.h"
 #include "wayland/meta-wayland-data-device.h"
 #include "wayland/meta-wayland-dma-buf.h"
 #include "wayland/meta-wayland-egl-stream.h"
@@ -428,7 +429,7 @@ meta_wayland_compositor_setup (MetaWaylandCompositor *compositor)
 			 compositor, compositor_bind))
     g_error ("Failed to register the global wl_compositor");
 
-  wl_display_init_shm (compositor->wayland_display);
+  meta_wayland_init_shm (compositor);
 
   meta_wayland_outputs_init (compositor);
   meta_wayland_data_device_manager_init (compositor);