Examples: Split the hellogl2 example

Some small refactoring: shorten lines, use super() and move shader
code to constants.

Refactor the transparent option handling to be in line with the C++
example.

Call the OpenGL cleanup from hideEvent() instead of
QOpenGLContext::aboutToBeDestroyed() since the signal is emitted from
the destructor and thus has no effect for Python.

Pick-to: 6.6
Task-number: PYSIDE-2460
Task-number: PYSIDE-2206
Change-Id: I5d140db6e04baf88d2ac867d809c6cff9eb740b5
Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io>

1 files changed, 59 insertions, 0 deletions

diff --git a/examples/opengl/hellogl2/main.py b/examples/opengl/hellogl2/main.py
new file mode 100644
index 000000000..ea35c0077
--- /dev/null
+++ b/examples/opengl/hellogl2/main.py
@@ -0,0 +1,59 @@
+# Copyright (C) 2023 The Qt Company Ltd.
+# Copyright (C) 2013 Riverbank Computing Limited.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+"""PySide6 port of the opengl/hellogl2 example from Qt v6.x"""
+
+from argparse import ArgumentParser, RawTextHelpFormatter
+import sys
+from PySide6.QtCore import Qt
+from PySide6.QtGui import QSurfaceFormat
+from PySide6.QtWidgets import (QApplication, QMessageBox)
+
+
+try:
+    from window import Window
+    from glwidget import GLWidget
+except ImportError:
+    app = QApplication(sys.argv)
+    message_box = QMessageBox(QMessageBox.Critical, "OpenGL hellogl",
+                              "PyOpenGL must be installed to run this example.",
+                              QMessageBox.Close)
+    message_box.setDetailedText("Run:\npip install PyOpenGL PyOpenGL_accelerate")
+    message_box.exec()
+    sys.exit(1)
+
+
+if __name__ == '__main__':
+    app = QApplication(sys.argv)
+    parser = ArgumentParser(description="hellogl2",
+                            formatter_class=RawTextHelpFormatter)
+    parser.add_argument('--multisample', '-m', action='store_true',
+                        help='Use Multisampling')
+    parser.add_argument('--coreprofile', '-c', action='store_true',
+                        help='Use Core Profile')
+    parser.add_argument('--transparent', '-t', action='store_true',
+                        help='Transparent Windows')
+    options = parser.parse_args()
+
+    fmt = QSurfaceFormat()
+    fmt.setDepthBufferSize(24)
+    if options.multisample:
+        fmt.setSamples(4)
+    if options.coreprofile:
+        fmt.setVersion(3, 2)
+        fmt.setProfile(QSurfaceFormat.CoreProfile)
+    QSurfaceFormat.setDefaultFormat(fmt)
+
+    GLWidget.set_transparent(options.transparent)
+
+    main_window = Window()
+    if options.transparent:
+        main_window.setAttribute(Qt.WA_TranslucentBackground)
+        main_window.setAttribute(Qt.WA_NoSystemBackground, False)
+
+    main_window.resize(main_window.sizeHint())
+    main_window.show()
+
+    res = app.exec()
+    sys.exit(res)