qgs3dmapsettings: Store debug overlay enabled flag

This stores the debug overlay visibility flag (mIsDebugOverlayEnabled)
even if it cannot be used (it needs at least Qt version 5.15). Its
default value is set to false to prevent any issue if the debug
overlay cannot be enabled.
This parameter is transient: it is not saved in the project
parameters.

The next commit will allow to this change this setting with
Qgs3DMapConfigWidget.

python/3d/auto_generated/qgs3dmapsettings.sip.in

@@ -642,7 +642,26 @@ Sets whether the camera's view frustum is visualized on the 2D map canvas
 .. versionadded:: 3.26
 %End
 
+    bool isDebugOverlayEnabled() const;
+%Docstring
+Returns whether debug overlay is enabled
 
+.. seealso:: :py:func:`setIsDebugOverlayEnabled`
+
+.. versionadded:: 3.26
+%End
+
+    void setIsDebugOverlayEnabled( bool debugOverlayEnabled );
+%Docstring
+Sets whether debug overlay is enabled
+The debug overlay displays some debugging and profiling information.
+It has been introduced in Qt version 5.15.
+This parameter is transient. It is not saved in the project parameters.
+
+.. seealso:: :py:func:`isDebugOverlayEnabled`
+
+.. versionadded:: 3.26
+%End
 
   signals:
 
@@ -871,6 +890,13 @@ Emitted when the camera's view frustum visualization on the main 2D map canvas i
 %Docstring
 Emitted when 3d axis rendering settings are changed
 
+.. versionadded:: 3.26
+%End
+
+    void debugOverlayEnabledChanged( bool debugOverlayEnabled );
+%Docstring
+Emitted when the debug overaly is enabled or disabled
+
 .. versionadded:: 3.26
 %End
 

src/3d/qgs3dmapsettings.cpp

@@ -92,7 +92,7 @@ Qgs3DMapSettings::Qgs3DMapSettings( const Qgs3DMapSettings &other )
   , mTerrainRenderingEnabled( other.mTerrainRenderingEnabled )
   , mRendererUsage( other.mRendererUsage )
   , m3dAxisSettings( other.m3dAxisSettings )
-
+  , mIsDebugOverlayEnabled( other.mIsDebugOverlayEnabled )
 {
   for ( QgsAbstract3DRenderer *renderer : std::as_const( other.mRenderers ) )
   {
@@ -917,6 +917,15 @@ void Qgs3DMapSettings::setViewFrustumVisualizationEnabled( bool enabled )
   }
 }
 
+void Qgs3DMapSettings::setIsDebugOverlayEnabled( bool debugOverlayEnabled )
+{
+  if ( debugOverlayEnabled == mIsDebugOverlayEnabled )
+    return;
+
+  mIsDebugOverlayEnabled = debugOverlayEnabled;
+  emit debugOverlayEnabledChanged( mIsDebugOverlayEnabled );
+}
+
 
 void Qgs3DMapSettings::connectChangedSignalsToSettingsChanged()
 {

src/3d/qgs3dmapsettings.h

@@ -640,6 +640,23 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject, public QgsTemporalRangeObjec
      */
     void set3dAxisSettings( const Qgs3DAxisSettings &axisSettings ) SIP_SKIP;
 
+    /**
+     * Returns whether debug overlay is enabled
+     * \see setIsDebugOverlayEnabled()
+     * \since QGIS 3.26
+     */
+    bool isDebugOverlayEnabled() const { return mIsDebugOverlayEnabled; }
+
+    /**
+     * Sets whether debug overlay is enabled
+     * The debug overlay displays some debugging and profiling information.
+     * It has been introduced in Qt version 5.15.
+     * This parameter is transient. It is not saved in the project parameters.
+     * \see isDebugOverlayEnabled()
+     * \since QGIS 3.26
+     */
+    void setIsDebugOverlayEnabled( bool debugOverlayEnabled );
+
   signals:
 
     /**
@@ -826,6 +843,12 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject, public QgsTemporalRangeObjec
      */
     void axisSettingsChanged();
 
+    /**
+     * Emitted when the debug overaly is enabled or disabled
+     * \since QGIS 3.26
+     */
+    void debugOverlayEnabledChanged( bool debugOverlayEnabled );
+
   private:
 #ifdef SIP_RUN
     Qgs3DMapSettings &operator=( const Qgs3DMapSettings & );
@@ -895,6 +918,8 @@ class _3D_EXPORT Qgs3DMapSettings : public QObject, public QgsTemporalRangeObjec
 
     Qgs3DAxisSettings m3dAxisSettings; //!< 3d axis related configuration
 
+    bool mIsDebugOverlayEnabled = false;
+
 };