Use opaque render list when client content is opaque

If the client says it's fully opaque through the
set_opaque_region request, we can disable blending
for the item and potentially improve performance a
little bit.

[ChangeLog][QtWaylandCompositor] The compositor now respects
the opaque region set by the client and no longer applies
blending or overdraw for fully opaque windows.

Fixes: QTBUG-100373
Change-Id: Iaa68fbf1f086d926c9c1867d981a63810f4ca855
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/compositor/compositor_api/qwaylandquickitem.cpp b/src/compositor/compositor_api/qwaylandquickitem.cpp
index bf1d0a447..07130a8a6 100644
--- a/src/compositor/compositor_api/qwaylandquickitem.cpp
+++ b/src/compositor/compositor_api/qwaylandquickitem.cpp
@@ -372,7 +372,7 @@ void QWaylandBufferMaterial::setBufferRef(QWaylandQuickItem *surfaceItem, const
         if (auto texture = ref.toOpenGLTexture(plane)) {
             QQuickWindow::CreateTextureOptions opt;
             QWaylandQuickSurface *waylandSurface = qobject_cast<QWaylandQuickSurface *>(surfaceItem->surface());
-            if (waylandSurface != nullptr && waylandSurface->useTextureAlpha())
+            if (waylandSurface != nullptr && waylandSurface->useTextureAlpha() && !waylandSurface->isOpaque())
                 opt |= QQuickWindow::TextureHasAlphaChannel;
             QSGTexture *scenegraphTexture;
             if (ref.bufferFormatEgl() == QWaylandBufferRef::BufferFormatEgl_EXTERNAL_OES) {
@@ -422,7 +422,7 @@ public:
 #if QT_CONFIG(opengl)
                 QQuickWindow::CreateTextureOptions opt;
                 QWaylandQuickSurface *surface = qobject_cast<QWaylandQuickSurface *>(surfaceItem->surface());
-                if (surface && surface->useTextureAlpha()) {
+                if (surface && surface->useTextureAlpha()  && !surface->isOpaque()) {
                     opt |= QQuickWindow::TextureHasAlphaChannel;
                 }