Respect nodata values in ::sample() for gdal provider

qgis · Sep 4, 2018 · 8af1c3f · 8af1c3f
1 parent 3463271
commit 8af1c3f
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diff --git a/src/providers/gdal/qgsgdalprovider.cpp b/src/providers/gdal/qgsgdalprovider.cpp
@@ -1138,6 +1138,13 @@ double QgsGdalProvider::sample( const QgsPointXY &point, int band, bool *ok, con
   if ( err != CE_None )
     return std::numeric_limits<double>::quiet_NaN();
 
+  if ( ( sourceHasNoDataValue( band ) && useSourceNoDataValue( band ) &&
+         ( std::isnan( value ) || qgsDoubleNear( static_cast< double >( value ), sourceNoDataValue( band ) ) ) ) ||
+       ( QgsRasterRange::contains( static_cast< double >( value ), userNoDataValues( band ) ) ) )
+  {
+    return std::numeric_limits<double>::quiet_NaN();
+  }
+
   if ( ok )
     *ok = true;
 

diff --git a/tests/src/core/testqgsrasterlayer.cpp b/tests/src/core/testqgsrasterlayer.cpp
@@ -794,6 +794,18 @@ void TestQgsRasterLayer::sample()
   QVERIFY( ok );
   QCOMPARE( rl->dataProvider()->sample( QgsPointXY( 17.943731, 30.230791 ), 2 ), 139.0 );
   QCOMPARE( rl->dataProvider()->sample( QgsPointXY( 17.943731, 30.230791 ), 3 ), 111.0 );
+
+  // src no data
+  rl->dataProvider()->setNoDataValue( 3, 111.0 );
+  ok = false;
+  QVERIFY( std::isnan( rl->dataProvider()->sample( QgsPointXY( 17.943731, 30.230791 ), 3, &ok ) ) );
+  QVERIFY( !ok );
+  rl->dataProvider()->setUseSourceNoDataValue( 3, false );
+  QCOMPARE( rl->dataProvider()->sample( QgsPointXY( 17.943731, 30.230791 ), 3 ), 111.0 );
+
+  rl->dataProvider()->setUserNoDataValue( 2, QgsRasterRangeList() << QgsRasterRange( 130, 140 ) );
+  QVERIFY( std::isnan( rl->dataProvider()->sample( QgsPointXY( 17.943731, 30.230791 ), 2, &ok ) ) );
+  QVERIFY( !ok );
 }
 
 QGSTEST_MAIN( TestQgsRasterLayer )