Move hellogles3 docs to where the rest of these files live

And expand the note in the openglwindow example to point to
hellogles3 as well.

Pick-to: 6.5
Change-Id: I2c0ee9b83fa59752d937c57eaf0194f0d0a8a7d9
Reviewed-by: Christian Strømme <christian.stromme@qt.io>

3 files changed, 30 insertions, 0 deletions

diff --git a/examples/opengl/doc/images/hellogles3-example.png b/examples/opengl/doc/images/hellogles3-example.png
new file mode 100644
index 0000000000..e089b9470a
--- /dev/null
+++ b/examples/opengl/doc/images/hellogles3-example.png
diff --git a/examples/opengl/doc/src/hellogles3.qdoc b/examples/opengl/doc/src/hellogles3.qdoc
new file mode 100644
index 0000000000..e76536d9d1
--- /dev/null
+++ b/examples/opengl/doc/src/hellogles3.qdoc
@@ -0,0 +1,28 @@
+// Copyright (C) 2018 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
+
+/*!
+    \example hellogles3
+    \title Hello GLES3 Example
+    \ingroup examples-widgets-opengl
+
+    \brief The Hello GLES3 example demonstrates easy, cross-platform usage of
+    OpenGL ES 3.0 functions via QOpenGLExtraFunctions in an application that
+    works identically on desktop platforms with OpenGL 3.3 and mobile/embedded
+    devices with OpenGL ES 3.0.
+
+    The code is always the same, with the exception of two places:
+    \list
+      \li The OpenGL context creation has to have a sufficiently high version
+    number for the features that are in use.
+      \li The shader code's version directive is different.
+    \endlist
+
+    This example has no QWidget dependencies. Instead, it uses QOpenGLWindow, a
+    convenience subclass of QWindow that allows easy implementation of windows
+    that contain OpenGL-rendered content. In this sense it complements the
+    \l{OpenGL Window Example}, which shows the implementation of an OpenGL-based
+    QWindow without using the convenience subclass.
+
+    \image hellogles3-example.png
+*/
diff --git a/examples/opengl/doc/src/openglwindow.qdoc b/examples/opengl/doc/src/openglwindow.qdoc
index 1a9d4308ba..505ff20fbc 100644
--- a/examples/opengl/doc/src/openglwindow.qdoc
+++ b/examples/opengl/doc/src/openglwindow.qdoc
@@ -12,6 +12,8 @@
 
     \note This is a low level example of how to use QWindow with OpenGL.
     In practice you should consider using the higher level QOpenGLWindow class.
+    See the \l{Hello GLES3 Example} for a demonstration of the QOpenGLWindow
+    convenience class.
 
     \section1 OpenGLWindow Super Class