Clean up QSGRhiSupport wrt static functions

Make static everything that can be static. At the same time, make
configure() non-static. Does not change behavior in any way, but
this is the more logical approach. Also more future proof.

Change-Id: I601d59a0547106802f330a7551a97186cde481e0
Reviewed-by: Christian Strømme <christian.stromme@qt.io>
(cherry picked from commit fb8ba3f7250f837dd29600d30108ba6f4470a727)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

3 files changed, 19 insertions, 23 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index a3d8b5eacb..697e5b3410 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -3665,7 +3665,7 @@ void QQuickWindow::setGraphicsApi(QSGRendererInterface::GraphicsApi api)
     // Standard case: tell the QRhi-based default adaptation what graphics api
     // (QRhi backend) to use.
     if (QSGRendererInterface::isApiRhiBased(api) || api == QSGRendererInterface::Unknown)
-        QSGRhiSupport::configure(api);
+        QSGRhiSupport::instance_internal()->configure(api);
 }
 
 /*!
diff --git a/src/quick/scenegraph/qsgrhisupport.cpp b/src/quick/scenegraph/qsgrhisupport.cpp
index 88bbf77e40..1ccca23596 100644
--- a/src/quick/scenegraph/qsgrhisupport.cpp
+++ b/src/quick/scenegraph/qsgrhisupport.cpp
@@ -252,12 +252,6 @@ void QSGRhiSupport::adjustToPlatformQuirks()
 #endif
 }
 
-QSGRhiSupport *QSGRhiSupport::staticInst()
-{
-    static QSGRhiSupport inst;
-    return &inst;
-}
-
 void QSGRhiSupport::checkEnvQSgInfo()
 {
     // For compatibility with 5.3 and earlier's QSG_INFO environment variables
@@ -269,21 +263,25 @@ void QSGRhiSupport::configure(QSGRendererInterface::GraphicsApi api)
 {
     if (api == QSGRendererInterface::Unknown) {
         // behave as if nothing was explicitly requested
-        QSGRhiSupport *inst = staticInst();
-        inst->m_requested.valid = false;
-        inst->applySettings();
+        m_requested.valid = false;
+        applySettings();
     } else {
         Q_ASSERT(QSGRendererInterface::isApiRhiBased(api));
-        QSGRhiSupport *inst = staticInst();
-        inst->m_requested.valid = true;
-        inst->m_requested.api = api;
-        inst->applySettings();
+        m_requested.valid = true;
+        m_requested.api = api;
+        applySettings();
     }
 }
 
+QSGRhiSupport *QSGRhiSupport::instance_internal()
+{
+    static QSGRhiSupport inst;
+    return &inst;
+}
+
 QSGRhiSupport *QSGRhiSupport::instance()
 {
-    QSGRhiSupport *inst = staticInst();
+    QSGRhiSupport *inst = instance_internal();
     if (!inst->m_settingsApplied)
         inst->applySettings();
     return inst;
diff --git a/src/quick/scenegraph/qsgrhisupport_p.h b/src/quick/scenegraph/qsgrhisupport_p.h
index 73fa2caad1..db710814bc 100644
--- a/src/quick/scenegraph/qsgrhisupport_p.h
+++ b/src/quick/scenegraph/qsgrhisupport_p.h
@@ -102,10 +102,15 @@ class QOffscreenSurface;
 class Q_QUICK_PRIVATE_EXPORT QSGRhiSupport
 {
 public:
-    static void configure(QSGRendererInterface::GraphicsApi api);
+    static QSGRhiSupport *instance_internal();
     static QSGRhiSupport *instance();
     static QVulkanInstance *defaultVulkanInstance();
     static void cleanupDefaultVulkanInstance();
+    static int chooseSampleCountForWindowWithRhi(QWindow *window, QRhi *rhi);
+    static QImage grabAndBlockInCurrentFrame(QRhi *rhi, QRhiCommandBuffer *cb, QRhiTexture *src = nullptr);
+    static void checkEnvQSgInfo();
+
+    void configure(QSGRendererInterface::GraphicsApi api);
 
     bool isRhiEnabled() const { return m_enableRhi; }
     QRhi::Implementation rhiBackend() const { return m_rhiBackend; }
@@ -123,24 +128,17 @@ public:
                             const QSGDefaultRenderContext *rc,
                             const QQuickWindow *w);
 
-    int chooseSampleCountForWindowWithRhi(QWindow *window, QRhi *rhi);
-
     QOffscreenSurface *maybeCreateOffscreenSurface(QWindow *window);
     QRhi *createRhi(QQuickWindow *window, QOffscreenSurface *offscreenSurface);
     void destroyRhi(QRhi *rhi);
     void prepareWindowForRhi(QQuickWindow *window);
 
-    QImage grabAndBlockInCurrentFrame(QRhi *rhi, QRhiCommandBuffer *cb, QRhiTexture *src = nullptr);
-
     QImage grabOffscreen(QQuickWindow *window);
 
-    static void checkEnvQSgInfo();
-
 private:
     QSGRhiSupport();
     void applySettings();
     void adjustToPlatformQuirks();
-    static QSGRhiSupport *staticInst();
     struct {
         bool valid = false;
         QSGRendererInterface::GraphicsApi api;