Add more methods to QgsPointCloudRenderer class

qgis · Nov 12, 2020 · 1feccd1 · 1feccd1
1 parent 1a2d6ec
commit 1feccd1
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Showing 3 changed files with 151 additions and 3 deletions.
diff --git a/python/core/auto_generated/pointcloud/qgspointcloudrenderer.sip.in b/python/core/auto_generated/pointcloud/qgspointcloudrenderer.sip.in
@@ -104,8 +104,61 @@ and generate a proper subclass.
 Renders a ``block`` of point cloud data using the specified render ``context``.
 %End
 
-};
+    static QgsPointCloudRenderer *load( QDomElement &element, const QgsReadWriteContext &context ) /Factory/;
+%Docstring
+Creates a renderer from an XML ``element``.
+
+Caller takes ownership of the returned renderer.
+
+.. seealso:: :py:func:`save`
+%End
+
+    virtual QDomElement save( QDomDocument &doc, const QgsReadWriteContext &context ) const = 0;
+%Docstring
+Saves the renderer configuration to an XML element.
+
+.. seealso:: :py:func:`load`
+%End
+
+    virtual QSet< QString > usedAttributes( const QgsPointCloudRenderContext &context ) const;
+%Docstring
+Returns a list of attributes required by this renderer. Attributes not listed in here may
+not be requested from the provider at rendering time.
+
+.. note::
+
+   the "X" and "Y" attributes will always be fetched and do not need to be explicitly
+   returned here.
+%End
 
+    virtual void startRender( QgsPointCloudRenderContext &context );
+%Docstring
+Must be called when a new render cycle is started. A call to :py:func:`~QgsPointCloudRenderer.startRender` must always
+be followed by a corresponding call to :py:func:`~QgsPointCloudRenderer.stopRender` after all features have been rendered.
+
+.. seealso:: :py:func:`stopRender`
+
+.. warning::
+
+   This method is not thread safe. Before calling :py:func:`~QgsPointCloudRenderer.startRender` in a non-main thread,
+   the renderer should instead be cloned and :py:func:`~QgsPointCloudRenderer.startRender`/:py:func:`~QgsPointCloudRenderer.stopRender` called on the clone.
+%End
+
+    virtual void stopRender( QgsPointCloudRenderContext &context );
+%Docstring
+Must be called when a render cycle has finished, to allow the renderer to clean up.
+
+Calls to :py:func:`~QgsPointCloudRenderer.stopRender` must always be preceded by a call to :py:func:`~QgsPointCloudRenderer.startRender`.
+
+.. warning::
+
+   This method is not thread safe. Before calling :py:func:`~QgsPointCloudRenderer.startRender` in a non-main thread,
+   the renderer should instead be cloned and :py:func:`~QgsPointCloudRenderer.startRender`/:py:func:`~QgsPointCloudRenderer.stopRender` called on the clone.
+
+.. seealso:: :py:func:`startRender`
+%End
+
+};
 
 /************************************************************************
  * This file has been generated automatically from                      *

diff --git a/src/core/pointcloud/qgspointcloudrenderer.cpp b/src/core/pointcloud/qgspointcloudrenderer.cpp
@@ -39,3 +39,48 @@ QgsPointCloudRenderer *QgsPointCloudRenderer::defaultRenderer()
 {
 
 }
+
+QgsPointCloudRenderer *QgsPointCloudRenderer::load( QDomElement &element, const QgsReadWriteContext &context )
+{
+  if ( element.isNull() )
+    return nullptr;
+
+  // load renderer
+  QString rendererType = element.attribute( QStringLiteral( "type" ) );
+
+#if 0
+  QgsRendererAbstractMetadata *m = QgsApplication::rendererRegistry()->rendererMetadata( rendererType );
+  if ( !m )
+    return nullptr;
+
+  std::unique_ptr< QgsPointCloudRenderer > r( m->createRenderer( element, context ) );
+  return r.release();
+#endif
+  return new QgsDummyPointCloudRenderer();
+}
+
+QSet<QString> QgsPointCloudRenderer::usedAttributes( const QgsPointCloudRenderContext & ) const
+{
+  return QSet< QString >();
+}
+
+void QgsPointCloudRenderer::startRender( QgsPointCloudRenderContext & )
+{
+#ifdef QGISDEBUG
+  if ( !mThread )
+  {
+    mThread = QThread::currentThread();
+  }
+  else
+  {
+    Q_ASSERT_X( mThread == QThread::currentThread(), "QgsPointCloudRenderer::startRender", "startRender called in a different thread - use a cloned renderer instead" );
+  }
+#endif
+}
+
+void QgsPointCloudRenderer::stopRender( QgsPointCloudRenderContext & )
+{
+#ifdef QGISDEBUG
+  Q_ASSERT_X( mThread == QThread::currentThread(), "QgsPointCloudRenderer::stopRender", "stopRender called in a different thread - use a cloned renderer instead" );
+#endif
+}
diff --git a/src/core/pointcloud/qgspointcloudrenderer.h b/src/core/pointcloud/qgspointcloudrenderer.h
@@ -118,7 +118,6 @@ class CORE_EXPORT QgsPointCloudRenderer
      */
     static QgsPointCloudRenderer *defaultRenderer() SIP_FACTORY;
 
-
     virtual ~QgsPointCloudRenderer() = default;
 
     /**
@@ -132,7 +131,58 @@ class CORE_EXPORT QgsPointCloudRenderer
      */
     virtual void renderBlock( const QgsPointCloudBlock *block, QgsPointCloudRenderContext &context ) = 0;
 
-};
+    /**
+     * Creates a renderer from an XML \a element.
+     *
+     * Caller takes ownership of the returned renderer.
+     *
+     * \see save()
+     */
+    static QgsPointCloudRenderer *load( QDomElement &element, const QgsReadWriteContext &context ) SIP_FACTORY;
+
+    /**
+     * Saves the renderer configuration to an XML element.
+     * \see load()
+     */
+    virtual QDomElement save( QDomDocument &doc, const QgsReadWriteContext &context ) const = 0;
+
+    /**
+     * Returns a list of attributes required by this renderer. Attributes not listed in here may
+     * not be requested from the provider at rendering time.
+     *
+     * \note the "X" and "Y" attributes will always be fetched and do not need to be explicitly
+     * returned here.
+     */
+    virtual QSet< QString > usedAttributes( const QgsPointCloudRenderContext &context ) const;
 
+    /**
+     * Must be called when a new render cycle is started. A call to startRender() must always
+     * be followed by a corresponding call to stopRender() after all features have been rendered.
+     *
+     * \see stopRender()
+     *
+     * \warning This method is not thread safe. Before calling startRender() in a non-main thread,
+     * the renderer should instead be cloned and startRender()/stopRender() called on the clone.
+     */
+    virtual void startRender( QgsPointCloudRenderContext &context );
+
+    /**
+     * Must be called when a render cycle has finished, to allow the renderer to clean up.
+     *
+     * Calls to stopRender() must always be preceded by a call to startRender().
+     *
+     * \warning This method is not thread safe. Before calling startRender() in a non-main thread,
+     * the renderer should instead be cloned and startRender()/stopRender() called on the clone.
+     *
+     * \see startRender()
+     */
+    virtual void stopRender( QgsPointCloudRenderContext &context );
+
+  private:
+#ifdef QGISDEBUG
+    //! Pointer to thread in which startRender was first called
+    QThread *mThread = nullptr;
+#endif
+};
 
 #endif // QGSPOINTCLOUDRENDERER_H