[labeling] Ensure short lines (wrt font size) still generate sufficient

candidates to ensure centered placement of labels
qgis · Jul 25, 2019 · 52f94a9 · 52f94a9
1 parent e10b09d
commit 52f94a9
Show file tree

Hide file tree

Showing 45 changed files with 54 additions and 1 deletion.
diff --git a/src/core/pal/feature.cpp b/src/core/pal/feature.cpp
@@ -1192,7 +1192,7 @@ int FeaturePart::createCurvedCandidatesAlongLine( QList< LabelPosition * > &lPos
   }
 
   QLinkedList<LabelPosition *> positions;
-  double delta = std::max( li->label_height, total_distance / mLF->layer()->pal->line_p );
+  double delta = std::max( li->label_height / 6, total_distance / mLF->layer()->pal->line_p );
 
   pal::LineArrangementFlags flags = mLF->arrangementFlags();
   if ( flags == 0 )

diff --git a/tests/src/core/testqgslabelingengine.cpp b/tests/src/core/testqgslabelingengine.cpp
@@ -59,6 +59,7 @@ class TestQgsLabelingEngine : public QObject
     void testCurvedLabelsWithTinySegments();
     void testCurvedLabelCorrectLinePlacement();
     void testCurvedLabelNegativeDistance();
+    void testCurvedLabelOnSmallLineNearCenter();
     void testParallelPlacementPreferAbove();
     void testLabelRotationWithReprojection();
     void labelingResults();
@@ -1173,6 +1174,58 @@ void TestQgsLabelingEngine::testCurvedLabelNegativeDistance()
   QVERIFY( imageCheck( QStringLiteral( "label_curved_negative_distance" ), img, 20 ) );
 }
 
+void TestQgsLabelingEngine::testCurvedLabelOnSmallLineNearCenter()
+{
+  // test a small line relative to label size still gives sufficient candidates to ensure more centered placements
+  // are found
+  QgsPalLayerSettings settings;
+  setDefaultLabelParams( settings );
+
+  QgsTextFormat format = settings.format();
+  format.setSize( 20 );
+  format.setColor( QColor( 0, 0, 0 ) );
+  settings.setFormat( format );
+
+  settings.fieldName = QStringLiteral( "'XXXXX'" );
+  settings.isExpression = true;
+  settings.placement = QgsPalLayerSettings::Curved;
+  settings.labelPerPart = false;
+
+  std::unique_ptr< QgsVectorLayer> vl2( new QgsVectorLayer( QStringLiteral( "LineString?crs=epsg:3946&field=id:integer" ), QStringLiteral( "vl" ), QStringLiteral( "memory" ) ) );
+  vl2->setRenderer( new QgsNullSymbolRenderer() );
+
+  QgsFeature f;
+  f.setAttributes( QgsAttributes() << 1 );
+  f.setGeometry( QgsGeometry::fromWkt( QStringLiteral( "LineString (190080 5000010, 190100 5000000, 190120 5000000)" ) ) );
+  QVERIFY( vl2->dataProvider()->addFeature( f ) );
+
+  vl2->setLabeling( new QgsVectorLayerSimpleLabeling( settings ) );  // TODO: this should not be necessary!
+  vl2->setLabelsEnabled( true );
+
+  // make a fake render context
+  QSize size( 640, 480 );
+  QgsMapSettings mapSettings;
+  mapSettings.setDestinationCrs( vl2->crs() );
+
+  mapSettings.setOutputSize( size );
+  mapSettings.setExtent( QgsRectangle( 190000, 5000000, 190200, 5000010 ) );
+  mapSettings.setLayers( QList<QgsMapLayer *>() << vl2.get() );
+  mapSettings.setOutputDpi( 96 );
+
+  QgsLabelingEngineSettings engineSettings = mapSettings.labelingEngineSettings();
+  engineSettings.setFlag( QgsLabelingEngineSettings::UsePartialCandidates, false );
+  engineSettings.setFlag( QgsLabelingEngineSettings::DrawLabelRectOnly, true );
+  //engineSettings.setFlag( QgsLabelingEngineSettings::DrawCandidates, true );
+  mapSettings.setLabelingEngineSettings( engineSettings );
+
+  QgsMapRendererSequentialJob job( mapSettings );
+  job.start();
+  job.waitForFinished();
+
+  QImage img = job.renderedImage();
+  QVERIFY( imageCheck( QStringLiteral( "label_curved_small_feature_centered" ), img, 20 ) );
+}
+
 void TestQgsLabelingEngine::testParallelPlacementPreferAbove()
 {
   // given the choice of above or below placement, labels should always be placed above

diff --git a/...xpected_pal_canvas_line/sp_curved_placement_above/sp_curved_placement_above.png b/...xpected_pal_canvas_line/sp_curved_placement_above/sp_curved_placement_above.png
diff --git a/...ed_pal_canvas_line/sp_curved_placement_above/sp_curved_placement_above_mask.png b/...ed_pal_canvas_line/sp_curved_placement_above/sp_curved_placement_above_mask.png
diff --git a/...xpected_pal_canvas_line/sp_curved_placement_below/sp_curved_placement_below.png b/...xpected_pal_canvas_line/sp_curved_placement_below/sp_curved_placement_below.png
diff --git a/...ed_pal_canvas_line/sp_curved_placement_below/sp_curved_placement_below_mask.png b/...ed_pal_canvas_line/sp_curved_placement_below/sp_curved_placement_below_mask.png
diff --git a/...ected_pal_canvas_line/sp_curved_placement_online/sp_curved_placement_online.png b/...ected_pal_canvas_line/sp_curved_placement_online/sp_curved_placement_online.png
diff --git a/..._pal_canvas_line/sp_curved_placement_online/sp_curved_placement_online_mask.png b/..._pal_canvas_line/sp_curved_placement_online/sp_curved_placement_online_mask.png
diff --git a/...l_images/expected_pal_canvas_line/sp_length_expression/sp_length_expression.png b/...l_images/expected_pal_canvas_line/sp_length_expression/sp_length_expression.png
diff --git a/...l_composer_line/sp_img_curved_placement_above/sp_img_curved_placement_above.png b/...l_composer_line/sp_img_curved_placement_above/sp_img_curved_placement_above.png
diff --git a/...poser_line/sp_img_curved_placement_above/sp_img_curved_placement_above_mask.png b/...poser_line/sp_img_curved_placement_above/sp_img_curved_placement_above_mask.png
diff --git a/...l_composer_line/sp_img_curved_placement_below/sp_img_curved_placement_below.png b/...l_composer_line/sp_img_curved_placement_below/sp_img_curved_placement_below.png
diff --git a/...poser_line/sp_img_curved_placement_below/sp_img_curved_placement_below_mask.png b/...poser_line/sp_img_curved_placement_below/sp_img_curved_placement_below_mask.png
diff --git a/...composer_line/sp_img_curved_placement_online/sp_img_curved_placement_online.png b/...composer_line/sp_img_curved_placement_online/sp_img_curved_placement_online.png
diff --git a/...ser_line/sp_img_curved_placement_online/sp_img_curved_placement_online_mask.png b/...ser_line/sp_img_curved_placement_online/sp_img_curved_placement_online_mask.png
diff --git a/...xpected_pal_composer_line/sp_img_length_expression/sp_img_length_expression.png b/...xpected_pal_composer_line/sp_img_length_expression/sp_img_length_expression.png
diff --git a/...l_composer_line/sp_pdf_curved_placement_above/sp_pdf_curved_placement_above.png b/...l_composer_line/sp_pdf_curved_placement_above/sp_pdf_curved_placement_above.png
diff --git a/...poser_line/sp_pdf_curved_placement_above/sp_pdf_curved_placement_above_mask.png b/...poser_line/sp_pdf_curved_placement_above/sp_pdf_curved_placement_above_mask.png
diff --git a/...l_composer_line/sp_pdf_curved_placement_below/sp_pdf_curved_placement_below.png b/...l_composer_line/sp_pdf_curved_placement_below/sp_pdf_curved_placement_below.png
diff --git a/...poser_line/sp_pdf_curved_placement_below/sp_pdf_curved_placement_below_mask.png b/...poser_line/sp_pdf_curved_placement_below/sp_pdf_curved_placement_below_mask.png
diff --git a/...composer_line/sp_pdf_curved_placement_online/sp_pdf_curved_placement_online.png b/...composer_line/sp_pdf_curved_placement_online/sp_pdf_curved_placement_online.png
diff --git a/...ser_line/sp_pdf_curved_placement_online/sp_pdf_curved_placement_online_mask.png b/...ser_line/sp_pdf_curved_placement_online/sp_pdf_curved_placement_online_mask.png
diff --git a/...xpected_pal_composer_line/sp_pdf_length_expression/sp_pdf_length_expression.png b/...xpected_pal_composer_line/sp_pdf_length_expression/sp_pdf_length_expression.png
diff --git a/...l_composer_line/sp_svg_curved_placement_above/sp_svg_curved_placement_above.png b/...l_composer_line/sp_svg_curved_placement_above/sp_svg_curved_placement_above.png
diff --git a/...poser_line/sp_svg_curved_placement_above/sp_svg_curved_placement_above_mask.png b/...poser_line/sp_svg_curved_placement_above/sp_svg_curved_placement_above_mask.png
diff --git a/...l_composer_line/sp_svg_curved_placement_below/sp_svg_curved_placement_below.png b/...l_composer_line/sp_svg_curved_placement_below/sp_svg_curved_placement_below.png
diff --git a/...poser_line/sp_svg_curved_placement_below/sp_svg_curved_placement_below_mask.png b/...poser_line/sp_svg_curved_placement_below/sp_svg_curved_placement_below_mask.png
diff --git a/...composer_line/sp_svg_curved_placement_online/sp_svg_curved_placement_online.png b/...composer_line/sp_svg_curved_placement_online/sp_svg_curved_placement_online.png
diff --git a/...ser_line/sp_svg_curved_placement_online/sp_svg_curved_placement_online_mask.png b/...ser_line/sp_svg_curved_placement_online/sp_svg_curved_placement_online_mask.png
diff --git a/...xpected_pal_composer_line/sp_svg_length_expression/sp_svg_length_expression.png b/...xpected_pal_composer_line/sp_svg_length_expression/sp_svg_length_expression.png
diff --git a/...l_placement/sp_label_curved_zero_width_char/sp_label_curved_zero_width_char.png b/...l_placement/sp_label_curved_zero_width_char/sp_label_curved_zero_width_char.png
diff --git a/...pal_placement/sp_polygon_placement_perimeter/sp_polygon_placement_perimeter.png b/...pal_placement/sp_polygon_placement_perimeter/sp_polygon_placement_perimeter.png
diff --git a/..._curved_above_instead_of_below/sp_prefer_line_curved_above_instead_of_below.png b/..._curved_above_instead_of_below/sp_prefer_line_curved_above_instead_of_below.png
diff --git a/...urved_above_instead_of_online/sp_prefer_line_curved_above_instead_of_online.png b/...urved_above_instead_of_online/sp_prefer_line_curved_above_instead_of_online.png
diff --git a/...urved_below_instead_of_online/sp_prefer_line_curved_below_instead_of_online.png b/...urved_below_instead_of_online/sp_prefer_line_curved_below_instead_of_online.png
diff --git a/...xpected_pal_server_line/sp_curved_placement_above/sp_curved_placement_above.png b/...xpected_pal_server_line/sp_curved_placement_above/sp_curved_placement_above.png
diff --git a/...xpected_pal_server_line/sp_curved_placement_below/sp_curved_placement_below.png b/...xpected_pal_server_line/sp_curved_placement_below/sp_curved_placement_below.png
diff --git a/...ected_pal_server_line/sp_curved_placement_online/sp_curved_placement_online.png b/...ected_pal_server_line/sp_curved_placement_online/sp_curved_placement_online.png
diff --git a/...ine/expected_label_curved_label_above_1/expected_label_curved_label_above_1.png b/...ine/expected_label_curved_label_above_1/expected_label_curved_label_above_1.png
diff --git a/...ine/expected_label_curved_label_below_1/expected_label_curved_label_below_1.png b/...ine/expected_label_curved_label_below_1/expected_label_curved_label_below_1.png
diff --git a/...abel_curved_label_small_segments/expected_label_curved_label_small_segments.png b/...abel_curved_label_small_segments/expected_label_curved_label_small_segments.png
diff --git a/...cted_label_curved_negative_distance/expected_label_curved_negative_distance.png b/...cted_label_curved_negative_distance/expected_label_curved_negative_distance.png
diff --git a/..._curved_small_feature_centered/expected_label_curved_small_feature_centered.png b/..._curved_small_feature_centered/expected_label_curved_small_feature_centered.png
diff --git a/...abel_multipart_touching_branches/expected_label_multipart_touching_branches.png b/...abel_multipart_touching_branches/expected_label_multipart_touching_branches.png
diff --git a/...cted_label_multipart_touching_lines/expected_label_multipart_touching_lines.png b/...cted_label_multipart_touching_lines/expected_label_multipart_touching_lines.png