Clarify docs and comments regarding under and overlays

Change-Id: I8973798996b6c775f425819af1d6a09f1773a9dc
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 5 insertions, 0 deletions

diff --git a/examples/quick/scenegraph/vulkanunderqml/vulkansquircle.cpp b/examples/quick/scenegraph/vulkanunderqml/vulkansquircle.cpp
index 3f2067a803..59e9606e7b 100644
--- a/examples/quick/scenegraph/vulkanunderqml/vulkansquircle.cpp
+++ b/examples/quick/scenegraph/vulkanunderqml/vulkansquircle.cpp
@@ -186,7 +186,12 @@ void VulkanSquircle::sync()
 {
     if (!m_renderer) {
         m_renderer = new SquircleRenderer;
+        // Initializing resources is done before starting to record the
+        // renderpass, regardless of wanting an underlay or overlay.
         connect(window(), &QQuickWindow::beforeRendering, m_renderer, &SquircleRenderer::frameStart, Qt::DirectConnection);
+        // Here we want an underlay and therefore connect to
+        // beforeRenderPassRecording. Changing to afterRenderPassRecording
+        // would render the squircle on top (overlay).
         connect(window(), &QQuickWindow::beforeRenderPassRecording, m_renderer, &SquircleRenderer::mainPassRecordingStart, Qt::DirectConnection);
     }
     m_renderer->setViewportSize(window()->size() * window()->devicePixelRatio());