[QGIS Commit] r13292 - trunk/qgis/src/core

[svn_qgis at osgeo.org]

Author: mhugent
Date: 2010-04-10 05:16:41 -0400 (Sat, 10 Apr 2010)
New Revision: 13292

Modified:
   trunk/qgis/src/core/qgsgeometry.cpp
   trunk/qgis/src/core/qgsgeometry.h
Log:
Use more accurate tolerances for some geometry modification methods if geom values in degrees

Modified: trunk/qgis/src/core/qgsgeometry.cpp
===================================================================
--- trunk/qgis/src/core/qgsgeometry.cpp	2010-04-09 07:42:30 UTC (rev 13291)
+++ trunk/qgis/src/core/qgsgeometry.cpp	2010-04-10 09:16:41 UTC (rev 13292)
@@ -5441,7 +5441,12 @@
     return -1;
   }
 
+
   double bufferDistance = 0.00001;
+  if ( geomInDegrees( line2 ) ) //use more accurate tolerance for degrees
+  {
+    bufferDistance = 0.00000001;
+  }
   GEOSGeometry* bufferGeom = GEOSBuffer( line2, bufferDistance, DEFAULT_QUADRANT_SEGMENTS );
   if ( !bufferGeom )
   {
@@ -5476,6 +5481,10 @@
   }
 
   double bufferDistance = 0.000001;
+  if ( geomInDegrees( line ) )
+  {
+    bufferDistance = 0.00000001;
+  }
   GEOSGeometry* lineBuffer = GEOSBuffer( line, bufferDistance, 8 );
   if ( !lineBuffer )
   {
@@ -5492,6 +5501,50 @@
   return contained;
 }
 
+bool QgsGeometry::geomInDegrees( const GEOSGeometry* geom )
+{
+  GEOSGeometry* bbox = GEOSEnvelope( geom );
+  if ( !bbox )
+  {
+    return false;
+  }
+
+  const GEOSGeometry* bBoxRing = GEOSGetExteriorRing( bbox );
+  if ( !bBoxRing )
+  {
+    return false;
+  }
+  const GEOSCoordSequence* bBoxCoordSeq = GEOSGeom_getCoordSeq( bBoxRing );
+
+  if ( !bBoxCoordSeq )
+  {
+    return false;
+  }
+
+  unsigned int nCoords = 0;
+  if ( !GEOSCoordSeq_getSize( bBoxCoordSeq, &nCoords ) )
+  {
+    return false;
+  }
+
+  double x, y;
+  for ( int i = 0; i < ( nCoords - 1 ); ++i )
+  {
+    GEOSCoordSeq_getX( bBoxCoordSeq, i, &x );
+    if ( x > 180 || x < -180 )
+    {
+      return false;
+    }
+    GEOSCoordSeq_getY( bBoxCoordSeq, i, &y );
+    if ( y > 90 || y < -90 )
+    {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 int QgsGeometry::numberOfGeometries( GEOSGeometry* g ) const
 {
   if ( !g )

Modified: trunk/qgis/src/core/qgsgeometry.h
===================================================================
--- trunk/qgis/src/core/qgsgeometry.h	2010-04-09 07:42:30 UTC (rev 13291)
+++ trunk/qgis/src/core/qgsgeometry.h	2010-04-10 09:16:41 UTC (rev 13292)
@@ -505,6 +505,9 @@
       @return 0 not contained, 1 if contained, <0 in case of error*/
     static int pointContainedInLine( const GEOSGeometry* point, const GEOSGeometry* line );
 
+    /**Tests if geom bounding rect is within -180 <= x <= 180, -90 <= y <= 90. Other methods may use more accurate tolerances if this is true*/
+    static bool geomInDegrees( const GEOSGeometry* geom );
+
     /**Returns number of single geometry in a geos geometry. Is save for geos 2 and 3*/
     int numberOfGeometries( GEOSGeometry* g ) const;