fix crashes in QGIS 3D, mostly directly at project load

qgis · Oct 11, 2020 · aa014d9 · aa014d9
1 parent 3686e01
commit aa014d9
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Showing 2 changed files with 17 additions and 7 deletions.
diff --git a/src/3d/terrain/qgsdemterraintileloader_p.cpp b/src/3d/terrain/qgsdemterraintileloader_p.cpp
@@ -25,6 +25,7 @@
 #include "qgsterraintileentity_p.h"
 
 #include <Qt3DRender/QGeometryRenderer>
+#include <QMutexLocker>
 
 ///@cond PRIVATE
 
@@ -265,21 +266,27 @@ QByteArray QgsDemHeightMapGenerator::renderSynchronously( int x, int y, int z )
   return data;
 }
 
-float QgsDemHeightMapGenerator::heightAt( double x, double y )
+void QgsDemHeightMapGenerator::lazyLoadDtmCoarseData( int res, const QgsRectangle &rect )
 {
-  if ( !mDtm )
-    return 0;  // TODO: calculate heights for online DTM
-
-  // TODO: this is quite a primitive implementation: better to use heightmaps currently in use
-  int res = 1024;
-  QgsRectangle rect = mDtm->extent();
+  QMutexLocker locker( &mLazyLoadDtmCoarseDataMutex );
   if ( mDtmCoarseData.isEmpty() )
   {
     std::unique_ptr< QgsRasterBlock > block( mDtm->dataProvider()->block( 1, rect, res, res ) );
     block->convert( Qgis::Float32 );
     mDtmCoarseData = block->data();
     mDtmCoarseData.detach();  // make a deep copy
   }
+}
+
+float QgsDemHeightMapGenerator::heightAt( double x, double y )
+{
+  if ( !mDtm )
+    return 0;  // TODO: calculate heights for online DTM
+
+  // TODO: this is quite a primitive implementation: better to use heightmaps currently in use
+  int res = 1024;
+  QgsRectangle rect = mDtm->extent();
+  lazyLoadDtmCoarseData( res, rect );
 
   int cellX = ( int )( ( x - rect.xMinimum() ) / rect.width() * res + .5f );
   int cellY = ( int )( ( rect.yMaximum() - y ) / rect.height() * res + .5f );

diff --git a/src/3d/terrain/qgsdemterraintileloader_p.h b/src/3d/terrain/qgsdemterraintileloader_p.h
@@ -30,6 +30,7 @@
 #include <QtConcurrent/QtConcurrentRun>
 #include <QFutureWatcher>
 #include <QElapsedTimer>
+#include <QMutex>
 
 #include "qgsrectangle.h"
 #include "qgsterraintileloader_p.h"
@@ -129,6 +130,8 @@ class QgsDemHeightMapGenerator : public QObject
 
     QHash<QFutureWatcher<QByteArray>*, JobData> mJobs;
 
+    void lazyLoadDtmCoarseData( int res, const QgsRectangle &rect );
+    mutable QMutex mLazyLoadDtmCoarseDataMutex;
     //! used for height queries
     QByteArray mDtmCoarseData;
 };