Handle different vector field types

mhugent · mhugent · commit 59545f1c6525 · 2011-11-01T14:35:34.000+01:00
diff --git a/python/core/symbology-ng-core.sip b/python/core/symbology-ng-core.sip
@@ -711,7 +711,7 @@ public:
   //! delete layer at specified index and set a new one
   bool changeSymbolLayer(int index, QgsSymbolLayerV2* layer /Transfer/);
 
-  void startRender( QgsRenderContext& context, const QgsVectorLayer* layer );
+  void startRender( QgsRenderContext& context, const QgsVectorLayer* layer = 0 );
   void stopRender(QgsRenderContext& context);
 
   void setColor(const QColor& color);
diff --git a/src/core/symbology-ng/qgsvectorfieldsymbollayer.cpp b/src/core/symbology-ng/qgsvectorfieldsymbollayer.cpp
@@ -105,6 +105,13 @@ void QgsVectorFieldSymbolLayer::renderPoint( const QPointF& point, QgsSymbolV2Re
       xComponent = context.outputLineWidth( xVal );
       yComponent = context.outputLineWidth( yVal );
       break;
+    case Polar:
+      convertPolarToCartesian( xVal, yVal, xComponent, yComponent );
+      xComponent = context.outputLineWidth( xComponent );
+      yComponent = context.outputLineWidth( yComponent );
+    case Height:
+      xComponent = 0;
+      yComponent = context.outputLineWidth( yVal );
     default:
       break;
   }
@@ -189,3 +196,27 @@ QSet<QString> QgsVectorFieldSymbolLayer::usedAttributes() const
   }
   return attributes;
 }
+
+void QgsVectorFieldSymbolLayer::convertPolarToCartesian( double length, double angle, double& x, double& y ) const
+{
+  //convert angle to degree and to north orientation
+  if ( mAngleOrientation == CounterclockwiseFromEast )
+  {
+    if ( angle <= 90 )
+    {
+      angle = 90 - angle;
+    }
+    else
+    {
+      angle = 360 - angle + 90;
+    }
+  }
+
+  if ( mAngleUnits == Degrees )
+  {
+    angle = angle * M_PI / 180.0;
+  }
+
+  x = length * sin( angle );
+  y = length * cos( angle );
+}
diff --git a/src/core/symbology-ng/qgsvectorfieldsymbollayer.h b/src/core/symbology-ng/qgsvectorfieldsymbollayer.h
@@ -91,6 +91,9 @@ class CORE_EXPORT QgsVectorFieldSymbolLayer: public QgsMarkerSymbolLayerV2
     //Attribute indices are resolved in startRender method
     int mXIndex;
     int mYIndex;
+
+    //Converts length/angle to cartesian x/y
+    void convertPolarToCartesian( double length, double angle, double& x, double& y ) const;
 };
 
 #endif // QGSVECTORFIELDSYMBOLLAYER_H
