Add a way to set the vsync_interval CVar from code (#5813)

* Add a way to set the render vsync from code

Signed-off-by: rgba16f <82187279+rgba16f@users.noreply.github.com>

* Update change with PR feedback. Missing whitespace plus a comment on why the assignment is outside the value changed check

Signed-off-by: rgba16f <82187279+rgba16f@users.noreply.github.com>

Code/Framework/AzCore/AzCore/Console/ConsoleDataWrapper.inl

@@ -32,7 +32,16 @@ namespace AZ
     template <typename BASE_TYPE, ThreadSafety THREAD_SAFETY>
     inline void ConsoleDataWrapper<BASE_TYPE, THREAD_SAFETY>::operator =(const BASE_TYPE& rhs)
     {
+        const BASE_TYPE currentValue = this->m_value;
+        // Do the value assignment outside new value check.
+        // Client code can supply a type for m_value that overrides the operator= function and trigger side effects
+        // in the operator= function body. Doing the assignment outside the value change check avoids those side
+        // effects not being triggered because AzCore believes the value wouldn't change.
         this->m_value = rhs;
+        if (currentValue != rhs)
+        {
+            InvokeCallback();
+        }
     }
 
     template <typename BASE_TYPE, ThreadSafety THREAD_SAFETY>

Code/Framework/AzFramework/AzFramework/Windowing/NativeWindow.cpp

@@ -143,6 +143,13 @@ namespace AzFramework
         return vsync_interval;
     }
 
+    bool NativeWindow::SetSyncInterval(uint32_t newSyncInterval)
+    {
+        vsync_interval = newSyncInterval;
+        return true;
+    }
+
+
     /*static*/ bool NativeWindow::GetFullScreenStateOfDefaultWindow()
     {
         NativeWindowHandle defaultWindowHandle = nullptr;

Code/Framework/AzFramework/AzFramework/Windowing/NativeWindow.h

@@ -132,6 +132,7 @@ namespace AzFramework
         void ToggleFullScreenState() override;
         float GetDpiScaleFactor() const override;
         uint32_t GetSyncInterval() const override;
+        bool SetSyncInterval(uint32_t newSyncInterval) override;
         uint32_t GetDisplayRefreshRate() const override;
 
         //! Get the full screen state of the default window.

Code/Framework/AzFramework/AzFramework/Windowing/WindowBus.h

@@ -78,6 +78,10 @@ namespace AzFramework
         //! Returns the sync interval which tells the drivers the number of v-blanks to synchronize with
         virtual uint32_t GetSyncInterval() const = 0;
 
+        //! Sets the sync interval which tells the drivers the number of v-blanks to synchronize with
+        //! Returns if the sync interval was succesfully set
+        virtual bool SetSyncInterval(uint32_t newSyncInterval) = 0;
+
         //! Returns the refresh rate of the main display
         virtual uint32_t GetDisplayRefreshRate() const = 0;
     };

Code/Framework/AzFramework/Tests/Mocks/MockWindowRequests.h

@@ -36,6 +36,7 @@ namespace UnitTest
         MOCK_METHOD0(ToggleFullScreenState, void());
         MOCK_CONST_METHOD0(GetDpiScaleFactor, float());
         MOCK_CONST_METHOD0(GetSyncInterval, uint32_t());
+        MOCK_METHOD1(SetSyncInterval, bool(uint32_t));
         MOCK_CONST_METHOD0(GetDisplayRefreshRate, uint32_t());
     };
 } // namespace UnitTest

Gems/Atom/Tools/AtomToolsFramework/Code/Include/AtomToolsFramework/Viewport/RenderViewportWidget.h

@@ -116,6 +116,7 @@ namespace AtomToolsFramework
         void ToggleFullScreenState() override;
         float GetDpiScaleFactor() const override;
         uint32_t GetSyncInterval() const override;
+        bool SetSyncInterval(uint32_t newSyncInterval) override;
         uint32_t GetDisplayRefreshRate() const override;
 
     protected:

Gems/Atom/Tools/AtomToolsFramework/Code/Source/Viewport/RenderViewportWidget.cpp

@@ -395,4 +395,11 @@ namespace AtomToolsFramework
     {
         return 1;
     }
+
+    // Editor ignores requests to change the sync interval
+    bool RenderViewportWidget::SetSyncInterval(uint32_t /*ignored*/)
+    {
+        return false;
+    }
+
 } //namespace AtomToolsFramework