Fix missing map settings expression variables in composer maps

Missing map extent related variables were causing stacking order
issues with the 25d renderer (fix #14604)

src/core/composer/qgscomposermap.cpp

@@ -2151,6 +2151,14 @@ QgsExpressionContext* QgsComposerMap::createExpressionContext() const
   scope->addVariable( QgsExpressionContextScope::StaticVariable( "map_id", QgsComposerItem::id(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( "map_rotation", mMapRotation, true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( "map_scale", scale(), true ) );
+
+  QgsRectangle extent( *currentMapExtent() );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "map_extent_width", extent.width(), true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "map_extent_height", extent.height(), true ) );
+  QgsGeometry* centerPoint = QgsGeometry::fromPoint( extent.center() );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "map_extent_center", QVariant::fromValue( *centerPoint ), true ) );
+  delete centerPoint;
+
   context->appendScope( scope );
 
   return context;

src/core/qgsexpressioncontext.cpp

@@ -713,6 +713,9 @@ void QgsExpressionContextUtils::setLayerVariables( QgsMapLayer* layer, const Qgs
 
 QgsExpressionContextScope* QgsExpressionContextUtils::mapSettingsScope( const QgsMapSettings& mapSettings )
 {
+  // IMPORTANT: ANY CHANGES HERE ALSO NEED TO BE MADE TO QgsComposerMap::createExpressionContext()
+  // (rationale is described in QgsComposerMap::createExpressionContext() )
+
   QgsExpressionContextScope* scope = new QgsExpressionContextScope( QObject::tr( "Map Settings" ) );
 
   //add known map settings context variables

tests/src/core/CMakeLists.txt

@@ -84,6 +84,7 @@ ENDMACRO (ADD_QGIS_TEST)
 #############################################################
 # Tests:
 
+ADD_QGIS_TEST(25drenderertest testqgs25drenderer.cpp)
 ADD_QGIS_TEST(applicationtest testqgsapplication.cpp)
 ADD_QGIS_TEST(atlascompositiontest testqgsatlascomposition.cpp)
 ADD_QGIS_TEST(authcryptotest testqgsauthcrypto.cpp)

tests/src/core/testqgs25drenderer.cpp

@@ -0,0 +1,163 @@
+/***************************************************************************
+     testqgs25drenderer.cpp
+     --------------------------------------
+    Date                 : April 2016
+    Copyright            : (C) 2016 by Nyall Dawson
+    Email                : nyall dot dawson at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#include <QtTest/QtTest>
+#include <QObject>
+#include <QString>
+#include <QStringList>
+#include <QApplication>
+#include <QFileInfo>
+#include <QDir>
+#include <QDesktopServices>
+
+//qgis includes...
+#include <qgsmapsettings.h>
+#include <qgsmaplayer.h>
+#include <qgsvectorlayer.h>
+#include <qgsapplication.h>
+#include <qgsproviderregistry.h>
+#include <qgsmaplayerregistry.h>
+#include <qgssymbolv2.h>
+#include <qgs25drenderer.h>
+#include "qgscomposition.h"
+#include "qgscomposermap.h"
+#include "qgsmultirenderchecker.h"
+
+/** \ingroup UnitTests
+ * This is a unit test for 25d renderer.
+ */
+class TestQgs25DRenderer : public QObject
+{
+    Q_OBJECT
+  public:
+    TestQgs25DRenderer()
+        : mpPolysLayer( nullptr )
+    {}
+
+  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 render();
+    void renderComposition();
+
+  private:
+    bool imageCheck( const QString& theType );
+    QgsMapSettings mMapSettings;
+    QgsVectorLayer * mpPolysLayer;
+    QString mTestDataDir;
+    QString mReport;
+};
+
+
+void TestQgs25DRenderer::initTestCase()
+{
+  // init QGIS's paths - true means that all path will be inited from prefix
+  QgsApplication::init();
+  QgsApplication::initQgis();
+  QgsApplication::showSettings();
+
+  //create some objects that will be used in all tests...
+  QString myDataDir( TEST_DATA_DIR ); //defined in CmakeLists.txt
+  mTestDataDir = myDataDir + '/';
+
+  //
+  //create a poly layer that will be used in all tests...
+  //
+  QString myPolysFileName = mTestDataDir + "polys.shp";
+  QFileInfo myPolyFileInfo( myPolysFileName );
+  mpPolysLayer = new QgsVectorLayer( myPolyFileInfo.filePath(),
+                                     myPolyFileInfo.completeBaseName(), "ogr" );
+
+  QgsVectorSimplifyMethod simplifyMethod;
+  simplifyMethod.setSimplifyHints( QgsVectorSimplifyMethod::NoSimplification );
+  mpPolysLayer->setSimplifyMethod( simplifyMethod );
+
+  //need a very high height to check for stacking
+  QgsExpressionContextUtils::setLayerVariable( mpPolysLayer, "qgis_25d_height", 8 );
+  QgsExpressionContextUtils::setLayerVariable( mpPolysLayer, "qgis_25d_angle", 45 );
+
+  // Register the layer with the registry
+  QgsMapLayerRegistry::instance()->addMapLayers(
+    QList<QgsMapLayer *>() << mpPolysLayer );
+
+  mMapSettings.setLayers( QStringList() << mpPolysLayer->id() );
+  mReport += "<h1>25D Renderer Tests</h1>\n";
+
+}
+void TestQgs25DRenderer::cleanupTestCase()
+{
+  QString myReportFile = QDir::tempPath() + "/qgistest.html";
+  QFile myFile( myReportFile );
+  if ( myFile.open( QIODevice::WriteOnly | QIODevice::Append ) )
+  {
+    QTextStream myQTextStream( &myFile );
+    myQTextStream << mReport;
+    myFile.close();
+  }
+
+  QgsApplication::exitQgis();
+}
+
+void TestQgs25DRenderer::render()
+{
+  mReport += "<h2>Render</h2>\n";
+
+  //setup 25d renderer
+  Qgs25DRenderer* renderer = new Qgs25DRenderer( );
+  renderer->setShadowEnabled( false );
+  renderer->setWallShadingEnabled( false );
+  mpPolysLayer->setRendererV2( renderer );
+
+  QVERIFY( imageCheck( "25d_render" ) );
+}
+
+void TestQgs25DRenderer::renderComposition()
+{
+  QgsComposition* composition = new QgsComposition( mMapSettings );
+  composition->setPaperSize( 297, 210 ); //A4 landscape
+  QgsComposerMap* map = new QgsComposerMap( composition, 20, 20, 200, 100 );
+  map->setFrameEnabled( true );
+  composition->addComposerMap( map );
+
+  map->setNewExtent( mpPolysLayer->extent() );
+  QgsCompositionChecker checker( "25d_composer", composition );
+  checker.setControlPathPrefix( "25d_renderer" );
+
+  QVERIFY( checker.testComposition( mReport, 0, 100 ) );
+}
+
+bool TestQgs25DRenderer::imageCheck( const QString& theTestType )
+{
+  //use the QgsRenderChecker test utility class to
+  //ensure the rendered output matches our control image
+  mMapSettings.setExtent( mpPolysLayer->extent() );
+  mMapSettings.setOutputDpi( 96 );
+  QgsExpressionContext context;
+  context << QgsExpressionContextUtils::mapSettingsScope( mMapSettings );
+  mMapSettings.setExpressionContext( context );
+  QgsMultiRenderChecker myChecker;
+  myChecker.setControlPathPrefix( "25d_renderer" );
+  myChecker.setControlName( "expected_" + theTestType );
+  myChecker.setMapSettings( mMapSettings );
+  myChecker.setColorTolerance( 20 );
+  bool myResultFlag = myChecker.runTest( theTestType, 500 );
+  mReport += myChecker.report();
+  return myResultFlag;
+}
+
+QTEST_MAIN( TestQgs25DRenderer )
+#include "testqgs25drenderer.moc"