Further tweaks to line labeling, add tests

Sponsored by Andreas Neumann (cherry-picked from dc0cc32) o
qgis · Aug 10, 2016 · a74dd61 · a74dd61
1 parent 34d5f5a
commit a74dd61
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Showing 16 changed files with 1,397 additions and 1 deletion.
diff --git a/src/core/pal/feature.cpp b/src/core/pal/feature.cpp
@@ -683,6 +683,7 @@ int FeaturePart::createCandidatesAlongLineNearStraightSegments( QList<LabelPosit
   straightSegmentLengths << currentStraightSegmentLength;
   straightSegmentAngles << QgsGeometryUtils::normalizedAngle( atan2( y[numberNodes-1] - segmentStartY, x[numberNodes-1] - segmentStartX ) );
   longestSegmentLength = qMax( longestSegmentLength, currentStraightSegmentLength );
+  double middleOfLine = totalLineLength / 2.0;
 
   if ( totalLineLength < labelWidth )
   {
@@ -729,6 +730,10 @@ int FeaturePart::createCandidatesAlongLineNearStraightSegments( QList<LabelPosit
 
       candidateLength = sqrt(( candidateEndX - candidateStartX ) * ( candidateEndX - candidateStartX ) + ( candidateEndY - candidateStartY ) * ( candidateEndY - candidateStartY ) );
 
+
+      // LOTS OF DIFFERENT COSTS TO BALANCE HERE - feel free to tweak these, but please add a unit test
+      // which covers the situation you are adjusting for (eg "given equal length lines, choose the more horizontal line")
+
       cost = candidateLength / labelWidth;
       if ( cost > 0.98 )
         cost = 0.0001;
@@ -738,10 +743,15 @@ int FeaturePart::createCandidatesAlongLineNearStraightSegments( QList<LabelPosit
         cost = ( 1 - cost ) / 100; // ranges from 0.0001 to 0.01 (however a cost 0.005 is already a lot!)
       }
 
-      // penalize positions which are further from the line's midpoint
+      // penalize positions which are further from the straight segments's midpoint
       double labelCenter = currentDistanceAlongLine + labelWidth / 2.0;
       double costCenter = 2 * qAbs( labelCenter - distanceToCenterOfSegment ) / ( distanceToEndOfSegment - distanceToStartOfSegment ); // 0 -> 1
       cost += costCenter * 0.0005;  // < 0, 0.0005 >
+
+      // penalize positions which are further from absolute center of whole linestring
+      double costLineCenter = 2 * qAbs( labelCenter - middleOfLine ) / totalLineLength; // 0 -> 1
+      cost += costLineCenter * 0.0005;  // < 0, 0.0005 >
+
       cost += segmentCost * 0.0005; // prefer labels on longer straight segments
       cost += segmentAngleCost * 0.0001; // prefer more horizontal segments, but this is less important than length considerations
 

diff --git a/tests/src/python/test_qgspallabeling_placement.py b/tests/src/python/test_qgspallabeling_placement.py
@@ -276,6 +276,7 @@ def test_polygon_placement_perimeter(self):
         self.layer = TestQgsPalLabeling.loadFeatureLayer('polygon_perimeter')
         self._TestMapSettings = self.cloneMapSettings(self._MapSettings)
         self.lyr.placement = QgsPalLayerSettings.Line
+        self.lyr.placementFlags = QgsPalLayerSettings.AboveLine
         self.checkTest()
         self.removeMapLayer(self.layer)
         self.layer = None
@@ -385,6 +386,51 @@ def test_prefer_line_below_instead_of_online(self):
         self.removeMapLayer(self.layer)
         self.layer = None
 
+    def test_prefer_longer_lines_over_shorter(self):
+        # Test that labeling a line using parallel labels will tend to place the labels over the longer straight parts of
+        # the line
+        self.layer = TestQgsPalLabeling.loadFeatureLayer('line_placement_1')
+        self._TestMapSettings = self.cloneMapSettings(self._MapSettings)
+        self.lyr.placement = QgsPalLayerSettings.Line
+        self.checkTest()
+        self.removeMapLayer(self.layer)
+        self.layer = None
+
+    def test_prefer_more_horizontal_lines(self):
+        # Test that labeling a line using parallel labels will tend to place the labels over more horizontal sections
+        self.layer = TestQgsPalLabeling.loadFeatureLayer('line_placement_2')
+        self._TestMapSettings = self.cloneMapSettings(self._MapSettings)
+        self.lyr.placement = QgsPalLayerSettings.Line
+        self.checkTest()
+        self.removeMapLayer(self.layer)
+        self.layer = None
+
+    def test_label_line_over_small_angles(self):
+        # Test that labeling a line using parallel labels will place labels near center of straightish line
+        self.layer = TestQgsPalLabeling.loadFeatureLayer('line_placement_3')
+        self._TestMapSettings = self.cloneMapSettings(self._MapSettings)
+        self.lyr.placement = QgsPalLayerSettings.Line
+        self.checkTest()
+        self.removeMapLayer(self.layer)
+        self.layer = None
+
+    def test_label_line_toward_center(self):
+        # Test that labeling a line using parallel labels will try to place labels as close to center of line as possible
+        self.layer = TestQgsPalLabeling.loadFeatureLayer('line_placement_4')
+        self._TestMapSettings = self.cloneMapSettings(self._MapSettings)
+        self.lyr.placement = QgsPalLayerSettings.Line
+        self.checkTest()
+        self.removeMapLayer(self.layer)
+        self.layer = None
+
+    def test_label_line_avoid_jaggy(self):
+        # Test that labeling a line using parallel labels won't place labels over jaggy bits of line
+        self.layer = TestQgsPalLabeling.loadFeatureLayer('line_placement_5')
+        self._TestMapSettings = self.cloneMapSettings(self._MapSettings)
+        self.lyr.placement = QgsPalLayerSettings.Line
+        self.checkTest()
+        self.removeMapLayer(self.layer)
+        self.layer = None
 
 if __name__ == '__main__':
     # NOTE: unless PAL_SUITE env var is set all test class methods will be run

diff --git a/.../expected_pal_placement/sp_label_line_avoid_jaggy/sp_label_line_avoid_jaggy.png b/.../expected_pal_placement/sp_label_line_avoid_jaggy/sp_label_line_avoid_jaggy.png
diff --git a/...l_placement/sp_label_line_over_small_angles/sp_label_line_over_small_angles.png b/...l_placement/sp_label_line_over_small_angles/sp_label_line_over_small_angles.png
diff --git a/...ected_pal_placement/sp_label_line_toward_center/sp_label_line_toward_center.png b/...ected_pal_placement/sp_label_line_toward_center/sp_label_line_toward_center.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/..._prefer_line_above_instead_of_online/sp_prefer_line_above_instead_of_online.png b/..._prefer_line_above_instead_of_online/sp_prefer_line_above_instead_of_online.png
diff --git a/..._prefer_line_below_instead_of_online/sp_prefer_line_below_instead_of_online.png b/..._prefer_line_below_instead_of_online/sp_prefer_line_below_instead_of_online.png
diff --git a/...ent/sp_prefer_longer_lines_over_shorter/sp_prefer_longer_lines_over_shorter.png b/...ent/sp_prefer_longer_lines_over_shorter/sp_prefer_longer_lines_over_shorter.png
diff --git a/...l_placement/sp_prefer_more_horizontal_lines/sp_prefer_more_horizontal_lines.png b/...l_placement/sp_prefer_more_horizontal_lines/sp_prefer_more_horizontal_lines.png
diff --git a/tests/testdata/labeling/line_placement_1.qml b/tests/testdata/labeling/line_placement_1.qml
@@ -0,0 +1,272 @@
+<!DOCTYPE qgis PUBLIC 'http://mrcc.com/qgis.dtd' 'SYSTEM'>
+<qgis version="2.99.0-Master" simplifyAlgorithm="0" minimumScale="100000" maximumScale="1e+08" simplifyDrawingHints="1" simplifyDrawingTol="1" simplifyMaxScale="1" hasScaleBasedVisibilityFlag="0" simplifyLocal="1">
+  <edittypes>
+    <edittype widgetv2type="TextEdit" name="pkuid">
+      <widgetv2config IsMultiline="0" fieldEditable="1" constraint="" UseHtml="0" labelOnTop="0" constraintDescription="" notNull="0"/>
+    </edittype>
+    <edittype widgetv2type="TextEdit" name="text">
+      <widgetv2config IsMultiline="0" fieldEditable="1" constraint="" UseHtml="0" labelOnTop="0" constraintDescription="" notNull="0"/>
+    </edittype>
+  </edittypes>
+  <renderer-v2 forceraster="0" symbollevels="0" type="singleSymbol" enableorderby="0">
+    <symbols>
+      <symbol alpha="1" clip_to_extent="1" type="line" name="0">
+        <layer pass="0" class="SimpleLine" locked="0">
+          <prop k="capstyle" v="square"/>
+          <prop k="customdash" v="5;2"/>
+          <prop k="customdash_map_unit_scale" v="0,0,0,0,0,0"/>
+          <prop k="customdash_unit" v="MM"/>
+          <prop k="draw_inside_polygon" v="0"/>
+          <prop k="joinstyle" v="bevel"/>
+          <prop k="line_color" v="227,26,28,255"/>
+          <prop k="line_style" v="solid"/>
+          <prop k="line_width" v="0.5"/>
+          <prop k="line_width_unit" v="MM"/>
+          <prop k="offset" v="0"/>
+          <prop k="offset_map_unit_scale" v="0,0,0,0,0,0"/>
+          <prop k="offset_unit" v="MM"/>
+          <prop k="use_custom_dash" v="0"/>
+          <prop k="width_map_unit_scale" v="0,0,0,0,0,0"/>
+        </layer>
+      </symbol>
+    </symbols>
+    <rotation/>
+    <sizescale scalemethod="diameter"/>
+  </renderer-v2>
+  <labeling type="simple"/>
+  <customproperties>
+    <property key="embeddedWidgets/count" value="0"/>
+    <property key="labeling" value="pal"/>
+    <property key="labeling/addDirectionSymbol" value="false"/>
+    <property key="labeling/angleOffset" value="0"/>
+    <property key="labeling/blendMode" value="0"/>
+    <property key="labeling/bufferBlendMode" value="0"/>
+    <property key="labeling/bufferColorA" value="255"/>
+    <property key="labeling/bufferColorB" value="255"/>
+    <property key="labeling/bufferColorG" value="255"/>
+    <property key="labeling/bufferColorR" value="255"/>
+    <property key="labeling/bufferDraw" value="false"/>
+    <property key="labeling/bufferJoinStyle" value="64"/>
+    <property key="labeling/bufferNoFill" value="false"/>
+    <property key="labeling/bufferSize" value="1"/>
+    <property key="labeling/bufferSizeInMapUnits" value="false"/>
+    <property key="labeling/bufferSizeMapUnitMaxScale" value="0"/>
+    <property key="labeling/bufferSizeMapUnitMinScale" value="0"/>
+    <property key="labeling/bufferSizeMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/bufferTransp" value="0"/>
+    <property key="labeling/centroidInside" value="false"/>
+    <property key="labeling/centroidWhole" value="false"/>
+    <property key="labeling/decimals" value="3"/>
+    <property key="labeling/displayAll" value="false"/>
+    <property key="labeling/dist" value="0"/>
+    <property key="labeling/distInMapUnits" value="false"/>
+    <property key="labeling/distMapUnitMaxScale" value="0"/>
+    <property key="labeling/distMapUnitMinScale" value="0"/>
+    <property key="labeling/distMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/drawLabels" value="false"/>
+    <property key="labeling/enabled" value="false"/>
+    <property key="labeling/fieldName" value=""/>
+    <property key="labeling/fitInPolygonOnly" value="false"/>
+    <property key="labeling/fontBold" value="false"/>
+    <property key="labeling/fontCapitals" value="0"/>
+    <property key="labeling/fontFamily" value="Ubuntu"/>
+    <property key="labeling/fontItalic" value="false"/>
+    <property key="labeling/fontLetterSpacing" value="0"/>
+    <property key="labeling/fontLimitPixelSize" value="false"/>
+    <property key="labeling/fontMaxPixelSize" value="10000"/>
+    <property key="labeling/fontMinPixelSize" value="3"/>
+    <property key="labeling/fontSize" value="11"/>
+    <property key="labeling/fontSizeInMapUnits" value="false"/>
+    <property key="labeling/fontSizeMapUnitMaxScale" value="0"/>
+    <property key="labeling/fontSizeMapUnitMinScale" value="0"/>
+    <property key="labeling/fontSizeMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/fontStrikeout" value="false"/>
+    <property key="labeling/fontUnderline" value="false"/>
+    <property key="labeling/fontWeight" value="63"/>
+    <property key="labeling/fontWordSpacing" value="0"/>
+    <property key="labeling/formatNumbers" value="false"/>
+    <property key="labeling/isExpression" value="true"/>
+    <property key="labeling/labelOffsetInMapUnits" value="true"/>
+    <property key="labeling/labelOffsetMapUnitMaxScale" value="0"/>
+    <property key="labeling/labelOffsetMapUnitMinScale" value="0"/>
+    <property key="labeling/labelOffsetMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/labelPerPart" value="false"/>
+    <property key="labeling/leftDirectionSymbol" value="&lt;"/>
+    <property key="labeling/limitNumLabels" value="false"/>
+    <property key="labeling/maxCurvedCharAngleIn" value="20"/>
+    <property key="labeling/maxCurvedCharAngleOut" value="-20"/>
+    <property key="labeling/maxNumLabels" value="2000"/>
+    <property key="labeling/mergeLines" value="false"/>
+    <property key="labeling/minFeatureSize" value="0"/>
+    <property key="labeling/multilineAlign" value="0"/>
+    <property key="labeling/multilineHeight" value="1"/>
+    <property key="labeling/namedStyle" value="Medium"/>
+    <property key="labeling/obstacle" value="true"/>
+    <property key="labeling/obstacleFactor" value="1"/>
+    <property key="labeling/obstacleType" value="0"/>
+    <property key="labeling/offsetType" value="0"/>
+    <property key="labeling/placeDirectionSymbol" value="0"/>
+    <property key="labeling/placement" value="2"/>
+    <property key="labeling/placementFlags" value="10"/>
+    <property key="labeling/plussign" value="false"/>
+    <property key="labeling/predefinedPositionOrder" value="TR,TL,BR,BL,R,L,TSR,BSR"/>
+    <property key="labeling/preserveRotation" value="true"/>
+    <property key="labeling/previewBkgrdColor" value="#ffffff"/>
+    <property key="labeling/priority" value="5"/>
+    <property key="labeling/quadOffset" value="4"/>
+    <property key="labeling/repeatDistance" value="0"/>
+    <property key="labeling/repeatDistanceMapUnitMaxScale" value="0"/>
+    <property key="labeling/repeatDistanceMapUnitMinScale" value="0"/>
+    <property key="labeling/repeatDistanceMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/repeatDistanceUnit" value="1"/>
+    <property key="labeling/reverseDirectionSymbol" value="false"/>
+    <property key="labeling/rightDirectionSymbol" value=">"/>
+    <property key="labeling/scaleMax" value="10000000"/>
+    <property key="labeling/scaleMin" value="1"/>
+    <property key="labeling/scaleVisibility" value="false"/>
+    <property key="labeling/shadowBlendMode" value="6"/>
+    <property key="labeling/shadowColorB" value="0"/>
+    <property key="labeling/shadowColorG" value="0"/>
+    <property key="labeling/shadowColorR" value="0"/>
+    <property key="labeling/shadowDraw" value="false"/>
+    <property key="labeling/shadowOffsetAngle" value="135"/>
+    <property key="labeling/shadowOffsetDist" value="1"/>
+    <property key="labeling/shadowOffsetGlobal" value="true"/>
+    <property key="labeling/shadowOffsetMapUnitMaxScale" value="0"/>
+    <property key="labeling/shadowOffsetMapUnitMinScale" value="0"/>
+    <property key="labeling/shadowOffsetMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/shadowOffsetUnits" value="1"/>
+    <property key="labeling/shadowRadius" value="1.5"/>
+    <property key="labeling/shadowRadiusAlphaOnly" value="false"/>
+    <property key="labeling/shadowRadiusMapUnitMaxScale" value="0"/>
+    <property key="labeling/shadowRadiusMapUnitMinScale" value="0"/>
+    <property key="labeling/shadowRadiusMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/shadowRadiusUnits" value="1"/>
+    <property key="labeling/shadowScale" value="100"/>
+    <property key="labeling/shadowTransparency" value="30"/>
+    <property key="labeling/shadowUnder" value="0"/>
+    <property key="labeling/shapeBlendMode" value="0"/>
+    <property key="labeling/shapeBorderColorA" value="255"/>
+    <property key="labeling/shapeBorderColorB" value="128"/>
+    <property key="labeling/shapeBorderColorG" value="128"/>
+    <property key="labeling/shapeBorderColorR" value="128"/>
+    <property key="labeling/shapeBorderWidth" value="0"/>
+    <property key="labeling/shapeBorderWidthMapUnitMaxScale" value="0"/>
+    <property key="labeling/shapeBorderWidthMapUnitMinScale" value="0"/>
+    <property key="labeling/shapeBorderWidthMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/shapeBorderWidthUnits" value="1"/>
+    <property key="labeling/shapeDraw" value="false"/>
+    <property key="labeling/shapeFillColorA" value="255"/>
+    <property key="labeling/shapeFillColorB" value="255"/>
+    <property key="labeling/shapeFillColorG" value="255"/>
+    <property key="labeling/shapeFillColorR" value="255"/>
+    <property key="labeling/shapeJoinStyle" value="64"/>
+    <property key="labeling/shapeOffsetMapUnitMaxScale" value="0"/>
+    <property key="labeling/shapeOffsetMapUnitMinScale" value="0"/>
+    <property key="labeling/shapeOffsetMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/shapeOffsetUnits" value="1"/>
+    <property key="labeling/shapeOffsetX" value="0"/>
+    <property key="labeling/shapeOffsetY" value="0"/>
+    <property key="labeling/shapeRadiiMapUnitMaxScale" value="0"/>
+    <property key="labeling/shapeRadiiMapUnitMinScale" value="0"/>
+    <property key="labeling/shapeRadiiMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/shapeRadiiUnits" value="1"/>
+    <property key="labeling/shapeRadiiX" value="0"/>
+    <property key="labeling/shapeRadiiY" value="0"/>
+    <property key="labeling/shapeRotation" value="0"/>
+    <property key="labeling/shapeRotationType" value="0"/>
+    <property key="labeling/shapeSVGFile" value=""/>
+    <property key="labeling/shapeSizeMapUnitMaxScale" value="0"/>
+    <property key="labeling/shapeSizeMapUnitMinScale" value="0"/>
+    <property key="labeling/shapeSizeMapUnitScale" value="0,0,0,0,0,0"/>
+    <property key="labeling/shapeSizeType" value="0"/>
+    <property key="labeling/shapeSizeUnits" value="1"/>
+    <property key="labeling/shapeSizeX" value="0"/>
+    <property key="labeling/shapeSizeY" value="0"/>
+    <property key="labeling/shapeTransparency" value="0"/>
+    <property key="labeling/shapeType" value="0"/>
+    <property key="labeling/textColorA" value="255"/>
+    <property key="labeling/textColorB" value="0"/>
+    <property key="labeling/textColorG" value="0"/>
+    <property key="labeling/textColorR" value="0"/>
+    <property key="labeling/textTransp" value="0"/>
+    <property key="labeling/upsidedownLabels" value="0"/>
+    <property key="labeling/wrapChar" value=""/>
+    <property key="labeling/xOffset" value="0"/>
+    <property key="labeling/yOffset" value="0"/>
+    <property key="labeling/zIndex" value="0"/>
+    <property key="variableNames" value="_fields_"/>
+    <property key="variableValues" value=""/>
+  </customproperties>
+  <blendMode>0</blendMode>
+  <featureBlendMode>0</featureBlendMode>
+  <layerTransparency>0</layerTransparency>
+  <SingleCategoryDiagramRenderer diagramType="Histogram" sizeLegend="0" attributeLegend="1">
+    <DiagramCategory penColor="#000000" labelPlacementMethod="XHeight" penWidth="0" diagramOrientation="Up" sizeScale="0,0,0,0,0,0" minimumSize="0" barWidth="5" penAlpha="255" maxScaleDenominator="1e+08" backgroundColor="#ffffff" transparency="0" width="15" scaleDependency="Area" backgroundAlpha="255" angleOffset="1440" scaleBasedVisibility="0" enabled="0" height="15" lineSizeScale="0,0,0,0,0,0" sizeType="MM" lineSizeType="MM" minScaleDenominator="100000">
+      <fontProperties description="Ubuntu,11,-1,5,50,0,0,0,0,0" style=""/>
+    </DiagramCategory>
+    <symbol alpha="1" clip_to_extent="1" type="marker" name="sizeSymbol">
+      <layer pass="0" class="SimpleMarker" locked="0">
+        <prop k="angle" v="0"/>
+        <prop k="color" v="255,0,0,255"/>
+        <prop k="horizontal_anchor_point" v="1"/>
+        <prop k="joinstyle" v="bevel"/>
+        <prop k="name" v="circle"/>
+        <prop k="offset" v="0,0"/>
+        <prop k="offset_map_unit_scale" v="0,0,0,0,0,0"/>
+        <prop k="offset_unit" v="MM"/>
+        <prop k="outline_color" v="0,0,0,255"/>
+        <prop k="outline_style" v="solid"/>
+        <prop k="outline_width" v="0"/>
+        <prop k="outline_width_map_unit_scale" v="0,0,0,0,0,0"/>
+        <prop k="outline_width_unit" v="MM"/>
+        <prop k="scale_method" v="diameter"/>
+        <prop k="size" v="2"/>
+        <prop k="size_map_unit_scale" v="0,0,0,0,0,0"/>
+        <prop k="size_unit" v="MM"/>
+        <prop k="vertical_anchor_point" v="1"/>
+      </layer>
+    </symbol>
+  </SingleCategoryDiagramRenderer>
+  <DiagramLayerSettings yPosColumn="-1" showColumn="-1" linePlacementFlags="10" placement="2" dist="0" xPosColumn="-1" priority="0" obstacle="0" zIndex="0" showAll="1"/>
+  <annotationform></annotationform>
+  <excludeAttributesWMS/>
+  <excludeAttributesWFS/>
+  <attributeactions default="-1"/>
+  <attributetableconfig actionWidgetStyle="dropDown" sortExpression="" sortOrder="0">
+    <columns>
+      <column width="-1" hidden="0" type="field" name="pkuid"/>
+      <column width="-1" hidden="0" type="field" name="text"/>
+      <column width="-1" hidden="1" type="actions"/>
+    </columns>
+  </attributetableconfig>
+  <editform></editform>
+  <editforminit/>
+  <editforminitcodesource>0</editforminitcodesource>
+  <editforminitfilepath></editforminitfilepath>
+  <editforminitcode><![CDATA[# -*- coding: utf-8 -*-
+"""
+QGIS forms can have a Python function that is called when the form is
+opened.
+
+Use this function to add extra logic to your forms.
+
+Enter the name of the function in the "Python Init function"
+field.
+An example follows:
+"""
+from qgis.PyQt.QtWidgets import QWidget
+
+def my_form_open(dialog, layer, feature):
+	geom = feature.geometry()
+	control = dialog.findChild(QWidget, "MyLineEdit")
+]]></editforminitcode>
+  <featformsuppress>0</featformsuppress>
+  <editorlayout>generatedlayout</editorlayout>
+  <widgets/>
+  <conditionalstyles>
+    <rowstyles/>
+    <fieldstyles/>
+  </conditionalstyles>
+  <layerGeometryType>1</layerGeometryType>
+</qgis>