Consider curved geometries in marker line symbol layer

qgis · Sep 4, 2015 · 56316dd · 56316dd
1 parent a5a963c
commit 56316dd
Show file tree

Hide file tree

Showing 24 changed files with 386 additions and 3 deletions.
diff --git a/python/core/geometry/qgsabstractgeometryv2.sip b/python/core/geometry/qgsabstractgeometryv2.sip
@@ -116,4 +116,8 @@ class QgsAbstractGeometryV2
     virtual bool hasCurvedSegments() const;
     /** Returns a geometry without curves. Caller takes ownership*/
     virtual QgsAbstractGeometryV2* segmentize() const /Factory/;
+
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    virtual double vertexAngle( const QgsVertexId& vertex ) const = 0;
 };
diff --git a/python/core/geometry/qgscircularstringv2.sip b/python/core/geometry/qgscircularstringv2.sip
@@ -55,6 +55,10 @@ class QgsCircularStringV2: public QgsCurveV2
 
     bool hasCurvedSegments() const;
 
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const;
+
   private:
     void segmentize( const QgsPointV2& p1, const QgsPointV2& p2, const QgsPointV2& p3, QList<QgsPointV2>& points ) const;
 };
diff --git a/python/core/geometry/qgscompoundcurvev2.sip b/python/core/geometry/qgscompoundcurvev2.sip
@@ -60,4 +60,8 @@ class QgsCompoundCurveV2: public QgsCurveV2
     void sumUpArea( double& sum ) const;
 
     bool hasCurvedSegments() const;
+
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const;
 };
diff --git a/python/core/geometry/qgscurvepolygonv2.sip b/python/core/geometry/qgscurvepolygonv2.sip
@@ -62,4 +62,8 @@ class QgsCurvePolygonV2: public QgsSurfaceV2
 
     bool hasCurvedSegments() const;
     QgsAbstractGeometryV2* segmentize() const /Factory/;
+
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const;
 };
diff --git a/python/core/geometry/qgsgeometrycollectionv2.sip b/python/core/geometry/qgsgeometrycollectionv2.sip
@@ -51,4 +51,8 @@ class QgsGeometryCollectionV2: public QgsAbstractGeometryV2
     virtual double area() const;
 
     bool hasCurvedSegments() const;
+
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const;
 };
diff --git a/python/core/geometry/qgslinestringv2.sip b/python/core/geometry/qgslinestringv2.sip
@@ -55,4 +55,8 @@ class QgsLineStringV2: public QgsCurveV2
     bool pointAt( int i, QgsPointV2& vertex, QgsVertexId::VertexType& type ) const;
 
     void sumUpArea( double& sum ) const;
+
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const;
 };
diff --git a/python/core/geometry/qgspointv2.sip b/python/core/geometry/qgspointv2.sip
@@ -55,4 +55,7 @@ class QgsPointV2: public QgsAbstractGeometryV2
 
       double closestSegment( const QgsPointV2& pt, QgsPointV2& segmentPt,  QgsVertexId& vertexAfter, bool* leftOf, double epsilon ) const;
       bool nextVertex( QgsVertexId& id, QgsPointV2& vertex ) const;
+
+      /** Angle undefined. Always returns 0.0*/
+      double vertexAngle( const QgsVertexId& vertex ) const;
 };
diff --git a/src/core/geometry/qgsabstractgeometryv2.h b/src/core/geometry/qgsabstractgeometryv2.h
@@ -317,6 +317,10 @@ class CORE_EXPORT QgsAbstractGeometryV2
      */
     virtual QgsAbstractGeometryV2* segmentize() const { return clone(); }
 
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    virtual double vertexAngle( const QgsVertexId& vertex ) const = 0;
+
   protected:
     QgsWKBTypes::Type mWkbType;
     mutable QgsRectangle mBoundingBox;

diff --git a/src/core/geometry/qgscircularstringv2.cpp b/src/core/geometry/qgscircularstringv2.cpp
@@ -953,3 +953,58 @@ void QgsCircularStringV2::insertVertexBetween( int after, int before, int pointO
     mM.insert( before, ( mM[after] + mM[before] ) / 2.0 );
   }
 }
+
+double QgsCircularStringV2::vertexAngle( const QgsVertexId& vId ) const
+{
+  int before = vId.vertex - 1;
+  int vertex = vId.vertex;
+  int after = vId.vertex + 1;
+
+  if ( vId.vertex % 2 != 0 ) // a curve vertex
+  {
+    if ( vId.vertex >= 1 && vId.vertex < numPoints() - 1 )
+    {
+      return QgsGeometryUtils::circleTangentDirection( QgsPointV2( mX[vertex], mY[vertex] ), QgsPointV2( mX[before], mY[before] ),
+             QgsPointV2( mX[vertex], mY[vertex] ), QgsPointV2( mX[after], mY[after] ) );
+    }
+  }
+  else //a point vertex
+  {
+    if ( vId.vertex == 0 )
+    {
+      return QgsGeometryUtils::circleTangentDirection( QgsPointV2( mX[0], mY[0] ), QgsPointV2( mX[0], mY[0] ),
+             QgsPointV2( mX[1], mY[1] ), QgsPointV2( mX[2], mY[2] ) );
+    }
+    if ( vId.vertex >= numPoints() - 1 )
+    {
+      if ( numPoints() < 3 )
+      {
+        return 0.0;
+      }
+      int a = numPoints() - 3;
+      int b = numPoints() - 2;
+      int c = numPoints() - 1;
+      return QgsGeometryUtils::circleTangentDirection( QgsPointV2( mX[c], mY[c] ), QgsPointV2( mX[a], mY[a] ),
+             QgsPointV2( mX[b], mY[b] ), QgsPointV2( mX[c], mY[c] ) );
+    }
+    else
+    {
+      if ( vId.vertex + 2 > numPoints() - 1 )
+      {
+        return 0.0;
+      }
+
+      int vertex1 = vId.vertex - 2;
+      int vertex2 = vId.vertex - 1;
+      int vertex3 = vId.vertex;
+      double angle1 = QgsGeometryUtils::circleTangentDirection( QgsPointV2( mX[vertex3], mY[vertex3] ),
+                      QgsPointV2( mX[vertex1], mY[vertex1] ), QgsPointV2( mX[vertex2], mY[vertex2] ), QgsPointV2( mX[vertex3], mY[vertex3] ) );
+      int vertex4 = vId.vertex + 1;
+      int vertex5 = vId.vertex + 2;
+      double angle2 = QgsGeometryUtils::circleTangentDirection( QgsPointV2( mX[vertex3], mY[vertex3] ),
+                      QgsPointV2( mX[vertex3], mY[vertex3] ), QgsPointV2( mX[vertex4], mY[vertex4] ), QgsPointV2( mX[vertex5], mY[vertex5] ) );
+      return QgsGeometryUtils::averageAngle( angle1, angle2 );
+    }
+  }
+  return 0.0;
+}
diff --git a/src/core/geometry/qgscircularstringv2.h b/src/core/geometry/qgscircularstringv2.h
@@ -91,6 +91,10 @@ class CORE_EXPORT QgsCircularStringV2: public QgsCurveV2
 
     bool hasCurvedSegments() const override { return true; }
 
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const override;
+
   private:
     QVector<double> mX;
     QVector<double> mY;

diff --git a/src/core/geometry/qgscompoundcurvev2.cpp b/src/core/geometry/qgscompoundcurvev2.cpp
@@ -586,3 +586,25 @@ bool QgsCompoundCurveV2::hasCurvedSegments() const
   return false;
 }
 
+double QgsCompoundCurveV2::vertexAngle( const QgsVertexId& vertex ) const
+{
+  QList< QPair<int, QgsVertexId> > curveIds = curveVertexId( vertex );
+  if ( curveIds.size() == 1 )
+  {
+    QgsCurveV2* curve = mCurves[curveIds.at( 0 ).first];
+    return curve->vertexAngle( curveIds.at( 0 ).second );
+  }
+  else if ( curveIds.size() > 1 )
+  {
+    QgsCurveV2* curve1 = mCurves[curveIds.at( 0 ).first];
+    QgsCurveV2* curve2 = mCurves[curveIds.at( 1 ).first];
+    double angle1 = curve1->vertexAngle( curveIds.at( 0 ).second );
+    double angle2 = curve2->vertexAngle( curveIds.at( 1 ).second );
+    return QgsGeometryUtils::averageAngle( angle1, angle2 );
+  }
+  else
+  {
+    return 0.0;
+  }
+}
+
diff --git a/src/core/geometry/qgscompoundcurvev2.h b/src/core/geometry/qgscompoundcurvev2.h
@@ -104,6 +104,10 @@ class CORE_EXPORT QgsCompoundCurveV2: public QgsCurveV2
 
     bool hasCurvedSegments() const override;
 
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const override;
+
   private:
     QList< QgsCurveV2* > mCurves;
     /** Turns a vertex id for the compound curve into one or more ids for the subcurves

diff --git a/src/core/geometry/qgscurvepolygonv2.cpp b/src/core/geometry/qgscurvepolygonv2.cpp
@@ -665,3 +665,14 @@ QgsAbstractGeometryV2* QgsCurvePolygonV2::segmentize() const
 {
   return toPolygon();
 }
+
+double QgsCurvePolygonV2::vertexAngle( const QgsVertexId& vertex ) const
+{
+  if ( !mExteriorRing || vertex.ring < 0 || vertex.ring >= 1 + mInteriorRings.size() )
+  {
+    return false;
+  }
+
+  QgsCurveV2* ring = vertex.ring == 0 ? mExteriorRing : mInteriorRings[vertex.ring - 1];
+  return ring->vertexAngle( vertex );
+}
diff --git a/src/core/geometry/qgscurvepolygonv2.h b/src/core/geometry/qgscurvepolygonv2.h
@@ -94,6 +94,10 @@ class CORE_EXPORT QgsCurvePolygonV2: public QgsSurfaceV2
     bool hasCurvedSegments() const override;
     QgsAbstractGeometryV2* segmentize() const override;
 
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const override;
+
   protected:
 
     QgsCurveV2* mExteriorRing;

diff --git a/src/core/geometry/qgsgeometrycollectionv2.cpp b/src/core/geometry/qgsgeometrycollectionv2.cpp
@@ -509,3 +509,19 @@ QgsAbstractGeometryV2* QgsGeometryCollectionV2::segmentize() const
   }
   return geomCollection;
 }
+
+double QgsGeometryCollectionV2::vertexAngle( const QgsVertexId& vertex ) const
+{
+  if ( vertex.part >= mGeometries.size() )
+  {
+    return 0.0;
+  }
+
+  QgsAbstractGeometryV2* geom = mGeometries[vertex.part];
+  if ( !geom )
+  {
+    return 0.0;
+  }
+
+  return geom->vertexAngle( vertex );
+}
diff --git a/src/core/geometry/qgsgeometrycollectionv2.h b/src/core/geometry/qgsgeometrycollectionv2.h
@@ -102,6 +102,10 @@ class CORE_EXPORT QgsGeometryCollectionV2: public QgsAbstractGeometryV2
     /** Returns a geometry without curves. Caller takes ownership*/
     QgsAbstractGeometryV2* segmentize() const override;
 
+    /** Returns approximate rotation angle for a vertex. Usually average angle between adjacent segments.
+        @return rotation in radians, clockwise from north*/
+    double vertexAngle( const QgsVertexId& vertex ) const override;
+
   protected:
     QVector< QgsAbstractGeometryV2* > mGeometries;
 

diff --git a/src/core/geometry/qgsgeometryutils.cpp b/src/core/geometry/qgsgeometryutils.cpp
@@ -357,6 +357,26 @@ bool QgsGeometryUtils::segmentMidPoint( const QgsPointV2& p1, const QgsPointV2&
   return true;
 }
 
+double QgsGeometryUtils::circleTangentDirection( const QgsPointV2& tangentPoint, const QgsPointV2& cp1,
+    const QgsPointV2& cp2, const QgsPointV2& cp3 )
+{
+  //calculate circle midpoint
+  double mX, mY, radius;
+  circleCenterRadius( cp1, cp2, cp3, radius, mX, mY );
+
+  double p1Angle = QgsGeometryUtils::ccwAngle( cp1.y() - mY, cp1.x() - mX );
+  double p2Angle = QgsGeometryUtils::ccwAngle( cp2.y() - mY, cp2.x() - mX );
+  double p3Angle = QgsGeometryUtils::ccwAngle( cp3.y() - mY, cp3.x() - mX );
+  if ( circleClockwise( p1Angle, p2Angle, p3Angle ) )
+  {
+    return lineAngle( tangentPoint.x(), tangentPoint.y(), mX, mY );
+  }
+  else
+  {
+    return lineAngle( mX, mY, tangentPoint.x(), tangentPoint.y() );
+  }
+}
+
 QList<QgsPointV2> QgsGeometryUtils::pointsFromWKT( const QString &wktCoordinateList, bool is3D, bool isMeasure )
 {
   int dim = 2 + is3D + isMeasure;
@@ -525,3 +545,71 @@ QStringList QgsGeometryUtils::wktGetChildBlocks( const QString &wkt, const QStri
   }
   return blocks;
 }
+
+double QgsGeometryUtils::lineAngle( double x1, double y1, double x2, double y2 )
+{
+  double at = atan2( y2 - y1, x2 - x1 );
+  double a = -at + M_PI / 2.0;
+  if ( a < 0 )
+  {
+    a = 2 * M_PI + a;
+  }
+  if ( a >= 2 * M_PI )
+  {
+    a -= 2 * M_PI;
+  }
+  return a;
+}
+
+double QgsGeometryUtils::linePerpendicularAngle( double x1, double y1, double x2, double y2 )
+{
+  double a = lineAngle( x1, y1, x2, y2 );
+  a += ( M_PI / 2.0 );
+  if ( a >= 2 * M_PI )
+  {
+    a -= ( 2 * M_PI );
+  }
+  return a;
+}
+
+double QgsGeometryUtils::averageAngle( double x1, double y1, double x2, double y2, double x3, double y3 )
+{
+  // calc average angle between the previous and next point
+  double a1 = linePerpendicularAngle( x1, y1, x2, y2 );
+  double a2 = linePerpendicularAngle( x2, y2, x3, y3 );
+  return averageAngle( a1, a2 );
+}
+
+double QgsGeometryUtils::averageAngle( double a1, double a2 )
+{
+  double clockwiseDiff = 0.0;
+  if ( a2 >= a1 )
+  {
+    clockwiseDiff = a2 - a1;
+  }
+  else
+  {
+    clockwiseDiff = a2 + ( 2 * M_PI - a1 );
+  }
+  double counterClockwiseDiff = 2 * M_PI - clockwiseDiff;
+
+  double resultAngle = 0;
+  if ( clockwiseDiff <= counterClockwiseDiff )
+  {
+    resultAngle = a1 + clockwiseDiff / 2.0;
+  }
+  else
+  {
+    resultAngle = a1 - counterClockwiseDiff / 2.0;
+  }
+
+  if ( resultAngle >= 2 * M_PI )
+  {
+    resultAngle -= 2 * M_PI;
+  }
+  else if ( resultAngle < 0 )
+  {
+    resultAngle = 2 * M_PI - resultAngle;
+  }
+  return resultAngle;
+}
diff --git a/src/core/geometry/qgsgeometryutils.h b/src/core/geometry/qgsgeometryutils.h
@@ -79,6 +79,9 @@ class CORE_EXPORT QgsGeometryUtils
     /** Calculates midpoint on circle passing through p1 and p2, closest to given coordinate*/
     static bool segmentMidPoint( const QgsPointV2& p1, const QgsPointV2& p2, QgsPointV2& result, double radius, const QgsPointV2& mousePos );
 
+    /** Calculates the direction angle of a circle tangent (clockwise from north in radians)*/
+    static double circleTangentDirection( const QgsPointV2& tangentPoint, const QgsPointV2& cp1, const QgsPointV2& cp2, const QgsPointV2& cp3 );
+
     /** Returns a list of points contained in a WKT string.
      */
     static QList<QgsPointV2> pointsFromWKT( const QString& wktCoordinateList, bool is3D, bool isMeasure );
@@ -93,6 +96,12 @@ class CORE_EXPORT QgsGeometryUtils
     /** Returns a geoJSON coordinates string */
     static QString pointsToJSON( const QList<QgsPointV2>& points, int precision );
 
+    static double lineAngle( double x1, double y1, double x2, double y2 );
+    static double linePerpendicularAngle( double x1, double y1, double x2, double y2 );
+    static double averageAngle( double x1, double y1, double x2, double y2, double x3, double y3 );
+    static double averageAngle( double a1, double a2 );
+
+
     /** Parses a WKT block of the format "TYPE( contents )" and returns a pair of geometry type to contents ("Pair(wkbType, "contents")")
      */
     static QPair<QgsWKBTypes::Type, QString> wktReadBlock( const QString& wkt );

diff --git a/src/core/geometry/qgslinestringv2.cpp b/src/core/geometry/qgslinestringv2.cpp
@@ -500,3 +500,34 @@ void QgsLineStringV2::close()
   }
   addVertex( startPoint() );
 }
+
+double QgsLineStringV2::vertexAngle( const QgsVertexId& vertex ) const
+{
+  if ( vertex.vertex == 0 || vertex.vertex >= ( numPoints() - 1 ) )
+  {
+    if ( isClosed() )
+    {
+      QPointF previous = mCoords[numPoints() - 1 ];
+      QPointF current = mCoords[0];
+      QPointF after = mCoords[1];
+      return QgsGeometryUtils::averageAngle( previous.x(), previous.y(), current.x(), current.y(), after.x(), after.y() );
+    }
+    else if ( vertex.vertex == 0 )
+    {
+      return QgsGeometryUtils::linePerpendicularAngle( mCoords[0].x(), mCoords[0].y(), mCoords[1].x(), mCoords[1].y() );
+    }
+    else
+    {
+      int a = numPoints() - 2;
+      int b = numPoints() - 1;
+      return QgsGeometryUtils::linePerpendicularAngle( mCoords[a].x(), mCoords[a].y(), mCoords[b].x(), mCoords[b].y() );
+    }
+  }
+  else
+  {
+    QPointF previous = mCoords[vertex.vertex - 1 ];
+    QPointF current = mCoords[vertex.vertex];
+    QPointF after = mCoords[vertex.vertex + 1];
+    return QgsGeometryUtils::averageAngle( previous.x(), previous.y(), current.x(), current.y(), after.x(), after.y() );
+  }
+}