Show how to really make QtWayland work under X11

Change-Id: Id584a74d1d0805034b10ea68ee7bf9bf8acccb63
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@hawaiios.org>

1 files changed, 30 insertions, 3 deletions

diff --git a/README b/README
index 7d9ed16bd..d0c5e03cf 100644
--- a/README
+++ b/README
@@ -18,13 +18,13 @@ QtWaylandCompositor as plugins. To specify what plugin to load use the environme
 variable QT_WAYLAND_CLIENT_BUFFER_INTEGRATION in the environment where the
 compositor is started. The compositor will broadcast to the clients which
 hardware integration to load when using the generic platformplugin "wayland". If
-no client buffer integration is specifided, then the wayland-egl plugin will be
+no client buffer integration is specified, then the wayland-egl plugin will be
 loaded. Please note that no Weston clients will work if the non standard
 wayland-egl client buffer integration is used.
 
-To start the qwindow-compositor with the xcomposite-egl integration then start
+To start the qwindow-compositor with the xcomposite-glx integration then start
 the compositor as follows:
-QT_WAYLAND_CLIENT_BUFFER_INTEGRATION=xcomposite-egl ./qwindow-compositor
+QT_WAYLAND_CLIENT_BUFFER_INTEGRATION=xcomposite-glx ./qwindow-compositor
 
 Now it should be possible to start an application in a separate terminal. ie:
 $QTBASEDIR/examples/opengl/hellowindow/hellowindow -platform wayland --single
@@ -35,6 +35,33 @@ brcm
 xcomposite-egl
 xcomposite-glx
 
+Testing a Qt-based compositor on X11:
+
+Most QWidget-based applications will use shared memory buffers, which work on
+all hardware. OpenGL and Qt Quick applications need a way to send graphics
+memory buffers from client to server. There are many options, and not all
+options work on all hardware.
+
+The X Composite buffer integration should work on all modern X servers. It
+can be used with either EGL or GLX as the OpenGL backend. This must match the
+backend used by the xcb platform plugin. (Normally GLX is the default for Qt
+applications running on X11.) To use the X Composite buffer sharing with EGL,
+start the compositor as follows:
+
+QT_XCB_GL_INTEGRATION=xcb_egl QT_WAYLAND_CLIENT_BUFFER_INTEGRATION=xcomposite-egl ./pure-qml
+
+Using wayland-egl requires support from the driver. Intel integrated graphics
+are supported through the standard Mesa drivers. For NVidia, driver version
+364.12 or newer is required, and Qt must be configured with "-opengl es2".
+Run the compositor as follows:
+
+QT_XCB_GL_INTEGRATION=xcb_egl QT_WAYLAND_CLIENT_BUFFER_INTEGRATION=wayland-egl ./minimal-qml
+
+Please note that some NVidia drivers may require early EGL initialization. Qt
+clients normally use the buffer integration communicated by the compositor.
+To set the client-side buffer integration manually, run clients with
+"-platform wayland-egl".
+
 Shell Integration:
 
 Some platforms, especially non-desktop ones, use a custom Wayland shell