Revert 3fdef5e

Was causing too many issues for the small perfomance gain it may have gained
qgis · Aug 14, 2015 · 9f10dbe · 9f10dbe
1 parent fec5d5e
commit 9f10dbe
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Showing 3 changed files with 58 additions and 53 deletions.
diff --git a/src/core/pal/feature.cpp b/src/core/pal/feature.cpp
@@ -504,6 +504,9 @@ namespace pal
     double xrm = mFeature->label_x;
     double yrm = mFeature->label_y;
 
+    double *d; // segments lengths distance bw pt[i] && pt[i+1]
+    double *ad;  // absolute distance bw pt[0] and pt[i] along the line
+    double ll; // line length
     double dist;
     double bx, by, ex, ey;
     int nbls;
@@ -529,7 +532,24 @@ namespace pal
     x = line->x;
     y = line->y;
 
-    double ll = line->length(); // line length
+    d = new double[nbPoints-1];
+    ad = new double[nbPoints];
+
+    ll = 0.0; // line length
+    for ( i = 0; i < line->nbPoints - 1; i++ )
+    {
+      if ( i == 0 )
+        ad[i] = 0;
+      else
+        ad[i] = ad[i-1] + d[i-1];
+
+      d[i] = dist_euc2d( x[i], y[i], x[i+1], y[i+1] );
+      ll += d[i];
+    }
+
+    ad[line->nbPoints-1] = ll;
+
+
     nbls = ( int )( ll / xrm ); // ratio bw line length and label width
 
 #ifdef _DEBUG_FULL_
@@ -564,9 +584,9 @@ namespace pal
     while ( l < ll - xrm )
     {
       // => bx, by
-      line->getPointByDistance( l, &bx, &by );
+      line->getPointByDistance( d, ad, l, &bx, &by );
       // same but l = l+xrm
-      line->getPointByDistance( l + xrm, &ex, &ey );
+      line->getPointByDistance( d, ad, l + xrm, &ex, &ey );
 
       // Label is bigger than line ...
       if ( l < 0 )
@@ -633,6 +653,11 @@ namespace pal
         break;
     }
 
+    //delete line;
+
+    delete[] d;
+    delete[] ad;
+
     int nbp = positions.size();
     *lPos = new LabelPosition *[nbp];
     i = 0;

diff --git a/src/core/pal/pointset.cpp b/src/core/pal/pointset.cpp
@@ -987,64 +987,42 @@ namespace pal
     }
   }
 
-  void PointSet::getPointByDistance( double distance, double *px, double *py ) const
+  void PointSet::getPointByDistance( double *d, double *ad, double dl, double *px, double *py )
   {
-    //if anything fails, return the first point
-    *px = x[0];
-    *py = y[0];
+    int i;
+    double dx, dy, di;
+    double distr;
 
-    if ( distance >= 0 )
+    i = 0;
+    if ( dl >= 0 )
     {
-      //positive distance, use GEOS for interpolation
-      if ( !mGeos )
-        createGeosGeom();
-
-      if ( !mGeos )
-        return;
+      while ( i < nbPoints && ad[i] <= dl ) i++;
+      i--;
+    }
 
-      GEOSContextHandle_t geosctxt = geosContext();
-      try
+    if ( i < nbPoints - 1 )
+    {
+      if ( dl < 0 )
       {
-        int type = GEOSGeomTypeId_r( geosctxt, mGeos );
-        const GEOSGeometry* lineString = 0;
-        if ( type != GEOS_POLYGON )
-        {
-          lineString = mGeos;
-        }
-        else
-        {
-          //for polygons, we need exterior ring
-          lineString = GEOSGetExteriorRing_r( geosctxt, mGeos );
-        }
-
-        GEOSGeometry *point = GEOSInterpolate_r( geosctxt, lineString, distance );
-        if ( point )
-        {
-          const GEOSCoordSequence *coordSeq = GEOSGeom_getCoordSeq_r( geosctxt, point );
-          GEOSCoordSeq_getX_r( geosctxt, coordSeq, 0, px );
-          GEOSCoordSeq_getY_r( geosctxt, coordSeq, 0, py );
-        }
-        GEOSGeom_destroy_r( geosctxt, point );
+        dx = x[nbPoints-1] - x[0];
+        dy = y[nbPoints-1] - y[0];
+        di = sqrt( dx * dx + dy * dy );
       }
-      catch ( GEOSException &e )
+      else
       {
-        QgsMessageLog::logMessage( QObject::tr( "Exception: %1" ).arg( e.what() ), QObject::tr( "GEOS" ) );
-        return;
+        dx = x[i+1] - x[i];
+        dy = y[i+1] - y[i];
+        di = d[i];
       }
+
+      distr = dl - ad[i];
+      *px = x[i] + dx * distr / di;
+      *py = y[i] + dy * distr / di;
     }
-    else
+    else    // just select last point...
     {
-      //negative distance. In this case we extrapolate backward from the first point,
-      //using the gradient of the entire linestring
-      double dx = x[nbPoints-1] - x[0];
-      double dy = y[nbPoints-1] - y[0];
-      double di = sqrt( dx * dx + dy * dy );
-
-      if ( di != 0.0 )
-      {
-        *px = x[0] + distance * dx / di;
-        *py = y[0] + distance * dy / di;
-      }
+      *px = x[i];
+      *py = y[i];
     }
   }
 

diff --git a/src/core/pal/pointset.h b/src/core/pal/pointset.h
@@ -124,11 +124,13 @@ namespace pal
       int getNumPoints() const { return nbPoints; }
 
       /** Get a point a set distance along a line geometry.
-       * @param distance distance to traverse along line
+       * @param d array of distances between points
+       * @param ad cumulative total distance from pt0 to each point (ad0 = pt0->pt0)
+       * @param dl distance to traverse along line
        * @param px final x coord on line
        * @param py final y coord on line
       */
-      void getPointByDistance( double distance, double *px, double *py ) const;
+      void getPointByDistance( double *d, double *ad, double dl, double *px, double *py );
 
       /** Returns the point set's GEOS geometry.
       */