Allow override WkbPtr and define WkbSimplifierPtr class

This commit simplifies the geometry just before to paint it in the
current QPainter device.

This commit allows to override the '>>' operators of the QgsWkbPtr
class. Also, It defines a new QgsWkbSimplifierPtr class to automatically
simplify the input point stream.

Author: ahuarte47

python/core/qgsclipper.sip

@@ -56,5 +56,5 @@ class QgsClipper
       @param wkb pointer to the start of the line wkb
       @param clipExtent clipping bounds
       @param line out: clipped line coordinates*/
-    static QgsConstWkbPtr clippedLineWKB( QgsConstWkbPtr wkb, const QgsRectangle& clipExtent, QPolygonF& line );
+    static QgsConstWkbPtr clippedLineWKB( QgsConstWkbPtr& wkb, const QgsRectangle& clipExtent, QPolygonF& line );
 };

python/core/qgsmaptopixelgeometrysimplifier.sip

@@ -29,6 +29,9 @@ class QgsMapToPixelSimplifier : QgsAbstractGeometrySimplifier
     //! Simplifies the specified geometry
     virtual bool simplifyGeometry( QgsGeometry* geometry ) const;
 
+    //! Simplifies the specified WKB-point array
+    virtual bool simplifyPoints( QgsWKBTypes::Type wkbType, QgsConstWkbPtr& sourceWkbPtr, QPolygonF& targetPoints ) const;
+
     // MapToPixel simplification helper methods
   public:
 
@@ -41,4 +44,7 @@ class QgsMapToPixelSimplifier : QgsAbstractGeometrySimplifier
     //! Simplifies the geometry when is applied the specified map2pixel context
     static bool simplifyGeometry( QgsGeometry* geometry, int simplifyFlags, double tolerance );
 
+    //! Simplifies the WKB-point array when is applied the specified map2pixel context
+    static bool simplifyPoints( QgsWKBTypes::Type wkbType, QgsConstWkbPtr& sourceWkbPtr, QPolygonF& targetPoints, int simplifyFlags, double tolerance );
+
 };

python/core/symbology-ng/qgsrendererv2.sip

@@ -403,9 +403,9 @@ class QgsFeatureRendererV2
     //! render editing vertex marker for a polygon
     void renderVertexMarkerPolygon( QPolygonF& pts, QList<QPolygonF>* rings, QgsRenderContext& context );
 
-    static QgsConstWkbPtr _getPoint( QPointF& pt, QgsRenderContext& context, QgsConstWkbPtr wkb );
-    static QgsConstWkbPtr _getLineString( QPolygonF& pts, QgsRenderContext& context, QgsConstWkbPtr wkb, bool clipToExtent = true );
-    static QgsConstWkbPtr _getPolygon( QPolygonF& pts, QList<QPolygonF>& holes, QgsRenderContext& context, QgsConstWkbPtr wkb, bool clipToExtent = true );
+    static QgsConstWkbPtr _getPoint( QPointF& pt, QgsRenderContext& context, QgsConstWkbPtr& wkb );
+    static QgsConstWkbPtr _getLineString( QPolygonF& pts, QgsRenderContext& context, QgsConstWkbPtr& wkb, bool clipToExtent = true );
+    static QgsConstWkbPtr _getPolygon( QPolygonF& pts, QList<QPolygonF>& holes, QgsRenderContext& context, QgsConstWkbPtr& wkb, bool clipToExtent = true );
 
     void setScaleMethodToSymbol( QgsSymbolV2* symbol, int scaleMethod );
 

python/core/symbology-ng/qgssymbolv2.sip

@@ -228,19 +228,19 @@ class QgsSymbolV2
      * Creates a point in screen coordinates from a wkb string in map
      * coordinates
      */
-    static QgsConstWkbPtr _getPoint( QPointF& pt, QgsRenderContext& context, QgsConstWkbPtr wkb );
+    static QgsConstWkbPtr _getPoint( QPointF& pt, QgsRenderContext& context, QgsConstWkbPtr& wkb );
 
     /**
      * Creates a line string in screen coordinates from a wkb string in map
      * coordinates
      */
-    static QgsConstWkbPtr _getLineString( QPolygonF& pts, QgsRenderContext& context, QgsConstWkbPtr wkb, bool clipToExtent = true );
+    static QgsConstWkbPtr _getLineString( QPolygonF& pts, QgsRenderContext& context, QgsConstWkbPtr& wkb, bool clipToExtent = true );
 
     /**
      * Creates a polygon in screen coordinates from a wkb string in map
      * coordinates
      */
-    static QgsConstWkbPtr _getPolygon( QPolygonF& pts, QList<QPolygonF>& holes, QgsRenderContext& context, QgsConstWkbPtr wkb, bool clipToExtent = true );
+    static QgsConstWkbPtr _getPolygon( QPolygonF& pts, QList<QPolygonF>& holes, QgsRenderContext& context, QgsConstWkbPtr& wkb, bool clipToExtent = true );
 
     /**
      * Retrieve a cloned list of all layers that make up this symbol.

src/core/CMakeLists.txt

@@ -352,6 +352,7 @@ SET(QGIS_CORE_SRCS
   geometry/qgspolygonv2.cpp
   geometry/qgswkbptr.cpp
   geometry/qgswkbtypes.cpp
+  geometry/qgswkbsimplifierptr.cpp
 
   ${CMAKE_CURRENT_BINARY_DIR}/qgscontexthelp_texts.cpp
   ${CMAKE_CURRENT_BINARY_DIR}/qgsexpression_texts.cpp
@@ -836,6 +837,7 @@ SET(QGIS_CORE_HDRS
   geometry/qgspointv2.h
   geometry/qgswkbptr.h
   geometry/qgswkbtypes.h
+  geometry/qgswkbsimplifierptr.h
 )
 
 IF (QT_MOBILITY_LOCATION_FOUND OR Qt5Positioning_FOUND)

src/core/geometry/qgswkbptr.cpp

@@ -32,6 +32,7 @@ QgsConstWkbPtr::QgsConstWkbPtr( const unsigned char *p, int size )
   mP = const_cast< unsigned char * >( p );
   mEnd = mP + size;
   mEndianSwap = false;
+  mWkbType = QgsWKBTypes::Unknown;
 }
 
 QgsWKBTypes::Type QgsConstWkbPtr::readHeader() const
@@ -45,12 +46,40 @@ QgsWKBTypes::Type QgsConstWkbPtr::readHeader() const
 
   int wkbType;
   *this >> wkbType;
+  mWkbType = static_cast<QgsWKBTypes::Type>( wkbType );
 
-  return static_cast<QgsWKBTypes::Type>( wkbType );
+  return mWkbType;
 }
 
 void QgsConstWkbPtr::verifyBound( int size ) const
 {
   if ( !mP || mP + size > mEnd )
     throw QgsWkbException( "wkb access out of bounds" );
 }
+
+const QgsConstWkbPtr &QgsConstWkbPtr::operator>>( QPointF &point ) const
+{
+  read( point.rx() );
+  read( point.ry() );
+  return *this;
+}
+
+const QgsConstWkbPtr &QgsConstWkbPtr::operator>>( QPolygonF &points ) const
+{
+  int skipZM = ( QgsWKBTypes::coordDimensions( mWkbType ) - 2 ) * sizeof( double );
+  Q_ASSERT( skipZM >= 0 );
+
+  unsigned int nPoints;
+  read( nPoints );
+
+  points.resize( nPoints );
+  QPointF* ptr = points.data();
+
+  for ( unsigned int i = 0; i < nPoints; ++i, ++ptr )
+  {
+    read( ptr->rx() );
+    read( ptr->ry() );
+    mP += skipZM;
+  }
+  return *this;
+}

src/core/geometry/qgswkbptr.h

@@ -19,6 +19,7 @@
 #include "qgsapplication.h"
 #include "qgis.h"
 #include "qgsexception.h"
+#include "qpolygon.h"
 
 /** \ingroup core
  *  * Custom exception class for Wkb related exceptions.
@@ -89,9 +90,11 @@ class CORE_EXPORT QgsWkbPtr
 
 class CORE_EXPORT QgsConstWkbPtr
 {
+  protected:
     mutable unsigned char *mP;
     unsigned char *mEnd;
     mutable bool mEndianSwap;
+    mutable QgsWKBTypes::Type mWkbType;
 
     void verifyBound( int size ) const;
 
@@ -114,6 +117,9 @@ class CORE_EXPORT QgsConstWkbPtr
     inline const QgsConstWkbPtr &operator>>( unsigned int &v ) const { read( v ); return *this; }
     inline const QgsConstWkbPtr &operator>>( char &v ) const { read( v ); return *this; }
 
+    virtual const QgsConstWkbPtr &operator>>( QPointF &point ) const;
+    virtual const QgsConstWkbPtr &operator>>( QPolygonF &points ) const;
+
     inline void operator+=( int n ) { verifyBound( n ); mP += n; }
     inline void operator-=( int n ) { mP -= n; }
 

src/core/geometry/qgswkbsimplifierptr.cpp

@@ -0,0 +1,47 @@
+/***************************************************************************
+    qgswkbsimplifierptr.cpp
+    ---------------------
+    begin                : February 2016
+    copyright            : (C) 2016 by Alvaro Huarte
+    email                : http://wiki.osgeo.org/wiki/Alvaro_Huarte
+ ***************************************************************************
+ *                                                                         *
+ *   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 "qgswkbsimplifierptr.h"
+#include "qgsgeometry.h"
+#include "qgssimplifymethod.h"
+#include "qgsmaptopixelgeometrysimplifier.h"
+
+QgsConstWkbSimplifierPtr::QgsConstWkbSimplifierPtr( const unsigned char *p, int size, const QgsVectorSimplifyMethod &simplifyMethod )
+    : QgsConstWkbPtr( p, size )
+    , mSimplifyMethod( simplifyMethod )
+{
+}
+
+const QgsConstWkbPtr &QgsConstWkbSimplifierPtr::operator>>( QPointF &point ) const
+{
+  return QgsConstWkbPtr::operator>>( point );
+}
+
+const QgsConstWkbPtr &QgsConstWkbSimplifierPtr::operator>>( QPolygonF &points ) const
+{
+  if ( mSimplifyMethod.simplifyHints() != QgsVectorSimplifyMethod::NoSimplification && mSimplifyMethod.forceLocalOptimization() )
+  {
+    int simplifyHints = mSimplifyMethod.simplifyHints() | QgsMapToPixelSimplifier::SimplifyEnvelope;
+
+    QgsConstWkbPtr wkbPtr = *this;
+
+    if ( QgsMapToPixelSimplifier::simplifyPoints( mWkbType, wkbPtr, points, simplifyHints, mSimplifyMethod.tolerance() ) )
+    {
+      mP = const_cast< unsigned char * >(( const unsigned char * ) wkbPtr );
+      return *this;
+    }
+  }
+  QgsConstWkbPtr::operator>>( points );
+  return *this;
+}

src/core/geometry/qgswkbsimplifierptr.h

@@ -0,0 +1,50 @@
+/***************************************************************************
+    qgswkbsimplifierptr.h
+    ---------------------
+    begin                : February 2016
+    copyright            : (C) 2016 by Alvaro Huarte
+    email                : http://wiki.osgeo.org/wiki/Alvaro_Huarte
+ ***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#ifndef QGSWKBSIMPLIFIERPTR_H
+#define QGSWKBSIMPLIFIERPTR_H
+
+#include "qgswkbptr.h"
+#include "qgsvectorsimplifymethod.h"
+
+class QgsGeometry;
+
+/** \class QgsConstWkbSimplifierPtr
+ * \note not available in Python bindings
+ */
+
+class CORE_EXPORT QgsConstWkbSimplifierPtr : public QgsConstWkbPtr
+{
+    /** Simplification object which holds the information about how to simplify the features for fast rendering */
+    const QgsVectorSimplifyMethod& mSimplifyMethod;
+
+  public:
+    QgsConstWkbSimplifierPtr( const unsigned char *p, int size, const QgsVectorSimplifyMethod &simplifyMethod );
+
+    inline const QgsConstWkbPtr &operator>>( double &v ) const { return QgsConstWkbPtr::operator>>( v ); }
+    inline const QgsConstWkbPtr &operator>>( float &r ) const { return QgsConstWkbPtr::operator>>( r ); }
+    inline const QgsConstWkbPtr &operator>>( int &v ) const { return QgsConstWkbPtr::operator>>( v ); }
+    inline const QgsConstWkbPtr &operator>>( unsigned int &v ) const { return QgsConstWkbPtr::operator>>( v ); }
+    inline const QgsConstWkbPtr &operator>>( char &v ) const { return QgsConstWkbPtr::operator>>( v ); }
+
+    virtual const QgsConstWkbPtr &operator>>( QPointF &point ) const override;
+    virtual const QgsConstWkbPtr &operator>>( QPolygonF &points ) const override;
+
+    inline void operator+=( int n ) { QgsConstWkbPtr::operator+=( n ); }
+    inline void operator-=( int n ) { QgsConstWkbPtr::operator-=( n ); }
+
+    inline operator const unsigned char *() const { return mP; }
+};
+
+#endif // QGSWKBSIMPLIFIERPTR_H

src/core/qgsclipper.cpp

@@ -38,7 +38,7 @@ const double QgsClipper::MIN_Y = -16000;
 
 const double QgsClipper::SMALL_NUM = 1e-12;
 
-QgsConstWkbPtr QgsClipper::clippedLineWKB( QgsConstWkbPtr wkbPtr, const QgsRectangle& clipExtent, QPolygonF& line )
+QgsConstWkbPtr QgsClipper::clippedLineWKB( QgsConstWkbPtr& wkbPtr, const QgsRectangle& clipExtent, QPolygonF& line )
 {
   QgsWKBTypes::Type wkbType = wkbPtr.readHeader();
 
@@ -57,24 +57,31 @@ QgsConstWkbPtr QgsClipper::clippedLineWKB( QgsConstWkbPtr wkbPtr, const QgsRecta
   double p1x_c, p1y_c; //clipped end coordinates
   double lastClipX = 0.0, lastClipY = 0.0; //last successfully clipped coords
 
+  QPolygonF pts;
+  wkbPtr -= sizeof( unsigned int );
+  wkbPtr >> pts;
+  nPoints = pts.size();
+
   line.clear();
   line.reserve( nPoints + 1 );
 
-  for ( int i = 0; i < nPoints; ++i )
+  QPointF *ptr = pts.data();
+
+  for ( int i = 0; i < nPoints; ++i, ++ptr )
   {
     if ( i == 0 )
     {
-      wkbPtr >> p1x >> p1y;
-      wkbPtr += skipZM;
+      p1x = ptr->rx();
+      p1y = ptr->ry();
       continue;
     }
     else
     {
       p0x = p1x;
       p0y = p1y;
 
-      wkbPtr >> p1x >> p1y;
-      wkbPtr += skipZM;
+      p1x = ptr->rx();
+      p1y = ptr->ry();
 
       p1x_c = p1x;
       p1y_c = p1y;

src/core/qgsclipper.h

@@ -87,7 +87,7 @@ class CORE_EXPORT QgsClipper
       @param wkb pointer to the start of the line wkb
       @param clipExtent clipping bounds
       @param line out: clipped line coordinates*/
-    static QgsConstWkbPtr clippedLineWKB( QgsConstWkbPtr wkb, const QgsRectangle& clipExtent, QPolygonF& line );
+    static QgsConstWkbPtr clippedLineWKB( QgsConstWkbPtr& wkb, const QgsRectangle& clipExtent, QPolygonF& line );
 
   private: