Make raster blend modes tests more robust

tests/src/core/testqgsblendmodes.cpp

@@ -51,8 +51,8 @@ class TestQgsBlendModes : public QObject
   private slots:
     void initTestCase();// will be called before the first testfunction is executed.
     void cleanupTestCase();// will be called after the last testfunction was executed.
-    void init() {};// will be called before each testfunction is executed.
-    void cleanup() {};// will be called after every testfunction.
+    void init() {} // will be called before each testfunction is executed.
+    void cleanup() {} // will be called after every testfunction.
 
     void vectorBlending();
     void featureBlending();
@@ -115,12 +115,12 @@ void TestQgsBlendModes::initTestCase()
     QList<QgsMapLayer *>() << mpLinesLayer );
 
   //create two raster layers
-  QFileInfo rasterFileInfo( mTestDataDir +  "landsat.tif" );
+  QFileInfo rasterFileInfo( mTestDataDir + "rgb256x256.png" );
   mRasterLayer1 = new QgsRasterLayer( rasterFileInfo.filePath(),
                                       rasterFileInfo.completeBaseName() );
   mRasterLayer2 = new QgsRasterLayer( rasterFileInfo.filePath(),
                                       rasterFileInfo.completeBaseName() );
-  QgsMultiBandColorRenderer* rasterRenderer = new QgsMultiBandColorRenderer( mRasterLayer1->dataProvider(), 2, 3, 4 );
+  QgsMultiBandColorRenderer* rasterRenderer = new QgsMultiBandColorRenderer( mRasterLayer1->dataProvider(), 1, 2, 3 );
   mRasterLayer1->setRenderer( rasterRenderer );
   mRasterLayer2->setRenderer(( QgsRasterRenderer* ) rasterRenderer->clone() );
   QgsMapLayerRegistry::instance()->addMapLayers(
@@ -214,7 +214,7 @@ void TestQgsBlendModes::rasterBlending()
   mMapSettings.setExtent( mRasterLayer1->extent() );
 
   // set blending mode for top layer
-  mRasterLayer1->setBlendMode( QPainter::CompositionMode_Plus );
+  mRasterLayer1->setBlendMode( QPainter::CompositionMode_Difference );
   QVERIFY( imageCheck( "raster_blendmodes" ) );
 }
 

tests/src/python/test_qgsblendmodes.py

@@ -76,13 +76,13 @@ class TestQgsBlendModes(TestCase):
         self.mMapRegistry.addMapLayer(self.mLineLayer)
 
         # create two raster layers
-        myRasterFile = os.path.join(TEST_DATA_DIR, 'landsat.tif')
+        myRasterFile = os.path.join(TEST_DATA_DIR, 'rgb256x256.png')
         self.mRasterLayer1 = QgsRasterLayer(myRasterFile, "raster1")
         self.mRasterLayer2 = QgsRasterLayer(myRasterFile, "raster2")
-        myMultiBandRenderer1 = QgsMultiBandColorRenderer(self.mRasterLayer1.dataProvider(), 2, 3, 4)
+        myMultiBandRenderer1 = QgsMultiBandColorRenderer(self.mRasterLayer1.dataProvider(), 1, 2, 3)
         self.mRasterLayer1.setRenderer(myMultiBandRenderer1)
         self.mMapRegistry.addMapLayer(self.mRasterLayer1)
-        myMultiBandRenderer2 = QgsMultiBandColorRenderer(self.mRasterLayer2.dataProvider(), 2, 3, 4)
+        myMultiBandRenderer2 = QgsMultiBandColorRenderer(self.mRasterLayer2.dataProvider(), 1, 2, 3)
         self.mRasterLayer2.setRenderer(myMultiBandRenderer2)
         self.mMapRegistry.addMapLayer(self.mRasterLayer2)
 
@@ -178,7 +178,7 @@ class TestQgsBlendModes(TestCase):
         self.mapSettings.setExtent(self.mRasterLayer1.extent())
 
         #Set blending mode for top layer
-        self.mRasterLayer1.setBlendMode(QPainter.CompositionMode_Plus)
+        self.mRasterLayer1.setBlendMode(QPainter.CompositionMode_Difference)
         checker = QgsMultiRenderChecker()
         checker.setControlName("expected_raster_blendmodes")
         checker.setMapSettings(self.mapSettings)