Fix GPU compositing (and WebGL) to work with ANGLE on Windows

Given the changes that implement GPU compositing on the UI thread (and
thus only a single thread accesses all OpenGL contexts) it is now
possible to enable GPU compositing to work together with ANGLE, which
did not work before due to ANGLE being thread-unsafe.

This requires a couple of things:
- Enable GPU compositing via kInProcessGPU switch when using ANGLE
- A small fix in GLContextHelper::getEGLDisplay() to return a
  correct "egldisplay "handle
- Improved logic when to pass the kDisableES3GLContext switch
  depending on which OpenGL ES version is requested (2 or 3)
- Adjustments in RenderWidgetHostViewQtDelegateWidget() to set up a
  correct surface format which matches the shared
  context OpenGL ES major version
- A recent enough version of ANGLE (due to bugs calling
  glTexImage2D with an unsupported internal texture format for
  GL_DEPTH_COMPONENT, from inside
  gpu::gles2::IsWebGLDrawBuffersSupported)

By default if no special QSurfaceFormat is set as the default
surface format, using ANGLE will create an OpenGL ES 2 context,
and will thus provide support only for WebGL 1.

To enable OpenGL ES 3 / WebGL 2 support, make sure to set a
default QSurfaceFormat with major version set to 3, and enable
ANGLE either via QT_OPENGL=angle or
QGuiApplication::setAttribute(Qt::AA_UseOpenGLES).

The default surface format must be set before the Q*App instance
is created.

Manual test "webgl" added.

Task-number: QTBUG-53908
Task-number: QTBUG-55604
Task-number: QTBUG-69236
Change-Id: Ic31dfdff1ca22d4689db5cf64126d7d12790aa76
Reviewed-by: Jüri Valdmann <juri.valdmann@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 22 insertions, 16 deletions

diff --git a/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp b/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp
index 7bbd85091..2753f5d3d 100644
--- a/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp
+++ b/src/webenginewidgets/render_widget_host_view_qt_delegate_widget.cpp
@@ -133,25 +133,31 @@ RenderWidgetHostViewQtDelegateWidget::RenderWidgetHostViewQtDelegateWidget(Rende
                    "QSurfaceFormat before the QtGui application instance is created.");
         }
 #endif
-
-        // Make sure the OpenGL profile of the QQuickWidget matches the shared context profile.
-        if (sharedFormat.profile() == QSurfaceFormat::CoreProfile) {
-            int major;
-            int minor;
-            QSurfaceFormat::OpenGLContextProfile profile;
-
+        int major;
+        int minor;
+        QSurfaceFormat::OpenGLContextProfile profile;
 #ifdef Q_OS_MACOS
-            // Due to QTBUG-63180, requesting the sharedFormat.majorVersion() on macOS will lead to
-            // a failed creation of QQuickWidget shared context. Thus make sure to request the
-            // major version specified in the defaultFormat instead.
-            major = defaultFormat.majorVersion();
-            minor = defaultFormat.minorVersion();
-            profile = defaultFormat.profile();
+        // Due to QTBUG-63180, requesting the sharedFormat.majorVersion() on macOS will lead to
+        // a failed creation of QQuickWidget shared context. Thus make sure to request the
+        // major version specified in the defaultFormat instead.
+        major = defaultFormat.majorVersion();
+        minor = defaultFormat.minorVersion();
+        profile = defaultFormat.profile();
 #else
-            major = sharedFormat.majorVersion();
-            minor = sharedFormat.minorVersion();
-            profile = sharedFormat.profile();
+        major = sharedFormat.majorVersion();
+        minor = sharedFormat.minorVersion();
+        profile = sharedFormat.profile();
+#endif
+
+        // Make sure the OpenGL profile of the QQuickWidget matches the shared context profile.
+        // It covers the following cases:
+        // 1) Desktop OpenGL Core Profile.
+        // 2) Windows ANGLE OpenGL ES profile.
+        if (sharedFormat.profile() == QSurfaceFormat::CoreProfile
+#ifdef Q_OS_WIN
+                || globalSharedContext->isOpenGLES()
 #endif
+                ) {
             format.setMajorVersion(major);
             format.setMinorVersion(minor);
             format.setProfile(profile);