More efficient handling of z range when rendering point clouds

Completely skip any nodes which are outside of the z range filter of the render context, instead of testing point by point
qgis · Nov 27, 2020 · 58c09a3 · 58c09a3
1 parent 033bcce
commit 58c09a3
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Showing 3 changed files with 36 additions and 6 deletions.
diff --git a/src/core/pointcloud/qgspointcloudindex.cpp b/src/core/pointcloud/qgspointcloudindex.cpp
@@ -139,6 +139,11 @@ QgsRectangle QgsPointCloudDataBounds::mapExtent( const QgsVector3D &offset, cons
          );
 }
 
+QgsDoubleRange QgsPointCloudDataBounds::zRange( const QgsVector3D &offset, const QgsVector3D &scale ) const
+{
+  return QgsDoubleRange( mZMin * scale.z() + offset.z(), mZMax * scale.z() + offset.z() );
+}
+
 ///@endcond
 
 
@@ -193,9 +198,14 @@ QgsPointCloudDataBounds QgsPointCloudIndex::nodeBounds( const IndexedPointCloudN
   return db;
 }
 
-QgsRectangle QgsPointCloudIndex::nodeMapExtent( const IndexedPointCloudNode &n ) const
+QgsRectangle QgsPointCloudIndex::nodeMapExtent( const IndexedPointCloudNode &node ) const
+{
+  return nodeBounds( node ).mapExtent( mOffset, mScale );
+}
+
+QgsDoubleRange QgsPointCloudIndex::nodeZRange( const IndexedPointCloudNode &node ) const
 {
-  return nodeBounds( n ).mapExtent( mOffset, mScale );
+  return nodeBounds( node ).zRange( mOffset, mScale );
 }
 
 float QgsPointCloudIndex::nodeError( const IndexedPointCloudNode &n ) const

diff --git a/src/core/pointcloud/qgspointcloudindex.h b/src/core/pointcloud/qgspointcloudindex.h
@@ -30,6 +30,7 @@
 #include "qgsvector3d.h"
 #include "qgis_sip.h"
 #include "qgspointcloudblock.h"
+#include "qgsrange.h"
 
 #define SIP_NO_FILE
 
@@ -122,6 +123,9 @@ class CORE_EXPORT QgsPointCloudDataBounds
     //! Returns 2D rectangle in map coordinates
     QgsRectangle mapExtent( const QgsVector3D &offset, const QgsVector3D &scale ) const;
 
+    //! Returns the z range, applying the specified \a offset and \a scale.
+    QgsDoubleRange zRange( const QgsVector3D &offset, const QgsVector3D &scale ) const;
+
   private:
     qint32 mXMin, mYMin, mZMin, mXMax, mYMax, mZMax;
 };
@@ -179,11 +183,22 @@ class CORE_EXPORT QgsPointCloudIndex: public QObject
     //! Returns z max
     double zMax() const { return mZMax; }
 
-    //! Returns bounds of particular node
-    QgsPointCloudDataBounds nodeBounds( const IndexedPointCloudNode &n ) const;
+    //! Returns bounds of particular \a node
+    QgsPointCloudDataBounds nodeBounds( const IndexedPointCloudNode &node ) const;
+
+    /**
+     * Returns the extent of a \a node in map coordinates.
+     *
+     * \see nodeZRange()
+     */
+    QgsRectangle nodeMapExtent( const IndexedPointCloudNode &node ) const;
 
-    //! Returns node extent in map coordinates
-    QgsRectangle nodeMapExtent( const IndexedPointCloudNode &n ) const;
+    /**
+     * Returns the z range of a \a node.
+     *
+     * \see nodeMapExtent()
+     */
+    QgsDoubleRange nodeZRange( const IndexedPointCloudNode &node ) const;
 
     //! Returns node's error in map units (used to determine in whether the node has enough detail for the current view)
     float nodeError( const IndexedPointCloudNode &n ) const;

diff --git a/src/core/pointcloud/qgspointcloudlayerrenderer.cpp b/src/core/pointcloud/qgspointcloudlayerrenderer.cpp
@@ -83,8 +83,10 @@ bool QgsPointCloudLayerRenderer::render()
 
   QgsPointCloudDataBounds db;
 
+#ifdef QGISDEBUG
   QElapsedTimer t;
   t.start();
+#endif
 
   const IndexedPointCloudNode root = pc->root();
 
@@ -162,6 +164,9 @@ QList<IndexedPointCloudNode> QgsPointCloudLayerRenderer::traverseTree( const Qgs
   if ( !context.extent().intersects( pc->nodeMapExtent( n ) ) )
     return nodes;
 
+  if ( !context.zRange().isInfinite() && !context.zRange().overlaps( pc->nodeZRange( n ) ) )
+    return nodes;
+
   nodes.append( n );
 
   float childrenErrorPixels = nodeErrorPixels / 2.0f;