pal: fixed calculation of distance from point to label. This fixes th…

…e problem with points not acting as obstacles.

git-svn-id: http://svn.osgeo.org/qgis/branches/symbology-ng-branch@11047 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/core/pal/labelposition.cpp

@@ -403,25 +403,24 @@ namespace pal
       my[i] = ( y[i] + y[j] ) / 2.0;
     }
 
-
-    if ( vabs( cross_product( mx[0], my[0], my[2], my[2], xp, yp ) / h ) < w / 2 )
+    if ( vabs( cross_product( mx[0], my[0], mx[2], my[2], xp, yp ) / h ) < w / 2 )
     {
-      dist = cross_product( x[0], y[0], x[1], y[1], xp, yp ) / w;
+      dist = cross_product( x[1], y[1], x[0], y[0], xp, yp ) / w;
       if ( vabs( dist ) < vabs( dist_min ) )
         dist_min = dist;
 
-      dist = cross_product( x[2], y[2], x[3], y[3], xp, yp ) / w;
+      dist = cross_product( x[3], y[3], x[2], y[2], xp, yp ) / w;
       if ( vabs( dist ) < vabs( dist_min ) )
         dist_min = dist;
     }
 
-    if ( vabs( cross_product( mx[1], my[1], my[3], my[3], xp, yp ) / w ) < h / 2 )
+    if ( vabs( cross_product( mx[1], my[1], mx[3], my[3], xp, yp ) / w ) < h / 2 )
     {
-      dist = cross_product( x[1], y[1], x[2], y[2], xp, yp ) / h;
+      dist = cross_product( x[2], y[2], x[1], y[1], xp, yp ) / h;
       if ( vabs( dist ) < vabs( dist_min ) )
         dist_min = dist;
 
-      dist = cross_product( x[3], y[3], x[0], y[0], xp, yp ) / h;
+      dist = cross_product( x[0], y[0], x[3], y[3], xp, yp ) / h;
       if ( vabs( dist ) < vabs( dist_min ) )
         dist_min = dist;
     }

src/core/pal/labelposition.h

@@ -220,7 +220,7 @@ namespace pal
       // for polygon cost calculation
       static bool polygonObstacleCallback( PointSet *feat, void *ctx );
 
-      /** get distance from this label to a point */
+      /** get distance from this label to a point. If point lies inside, returns negative number. */
       double getDistanceToPoint( double xp, double yp );
 
       /** returns true if this label crosses the specified line */