Merge branch 'featureReaderPerformance' into 'master'

Feature reader performance

Added minor Performance tweaks to the file Readers.
Unittests on Linux work fine.
compilation on Linux and Windows (vs2013) works fine.
i could not run unittests on Windows, as i have no gtest on my dev machine.

See merge request !1

src/OpenMesh/Core/IO/reader/OBJReader.cc

@@ -172,6 +172,8 @@ read_material(std::fstream& _in)
   std::string keyWrd;
   std::string textureName;
 
+  std::stringstream  stream;
+
   std::string key;
   Material    mat;
   float       f1,f2,f3;
@@ -193,7 +195,8 @@ read_material(std::fstream& _in)
     if ( line.empty() )
       continue;
 
-    std::stringstream stream(line);
+    stream.str(line);
+    stream.clear();
 
     stream >> keyWrd;
 
@@ -305,6 +308,8 @@ read(std::istream& _in, BaseImporter& _bi, Options& _opt)
 
   std::string               matname;
 
+  std::stringstream         stream, lineData, tmp;
+
 
   // Options supplied by the user
   Options userOptions = _opt;
@@ -329,7 +334,8 @@ read(std::istream& _in, BaseImporter& _bi, Options& _opt)
       continue;
     }
 
-    std::stringstream stream(line);
+    stream.str(line);
+    stream.clear();
 
     stream >> keyWrd;
 
@@ -463,7 +469,8 @@ read(std::istream& _in, BaseImporter& _bi, Options& _opt)
       // read full line after detecting a face
       std::string faceLine;
       std::getline(stream,faceLine);
-      std::stringstream lineData( faceLine );
+      lineData.str( faceLine );
+      lineData.clear();
 
       FaceHandle fh;
       BaseImporter::VHandles faceVertices;
@@ -484,7 +491,8 @@ read(std::istream& _in, BaseImporter& _bi, Options& _opt)
           if( found != std::string::npos ){
 
             // read the index value
-            std::stringstream tmp( vertex.substr(0,found) );
+            tmp.str( vertex.substr(0,found) );
+            tmp.clear();
 
             // If we get an empty string this property is undefined in the file
             if ( vertex.substr(0,found).empty() ) {
@@ -507,7 +515,8 @@ read(std::istream& _in, BaseImporter& _bi, Options& _opt)
           } else {
 
             // last component of the vertex, read it.
-            std::stringstream tmp( vertex );
+            tmp.str( vertex );
+            tmp.clear();
             tmp >> value;
 
             // Clear vertex after finished reading the line

src/OpenMesh/Core/IO/reader/OFFReader.cc

@@ -182,16 +182,18 @@ _OFFReader_::read_ascii(std::istream& _in, BaseImporter& _bi, Options& _opt) con
 {
 
 
-  unsigned int            i, j, k, l, idx;
-  unsigned int            nV, nF, dummy;
-  OpenMesh::Vec3f         v, n;
-  OpenMesh::Vec2f         t;
-  OpenMesh::Vec3i         c3;
-  OpenMesh::Vec3f         c3f;
-  OpenMesh::Vec4i         c4;
-  OpenMesh::Vec4f         c4f;
-  BaseImporter::VHandles  vhandles;
-  VertexHandle            vh;
+  unsigned int              i, j, k, l, idx;
+  unsigned int              nV, nF, dummy;
+  OpenMesh::Vec3f           v, n;
+  OpenMesh::Vec2f           t;
+  OpenMesh::Vec3i           c3;
+  OpenMesh::Vec3f           c3f;
+  OpenMesh::Vec4i           c4;
+  OpenMesh::Vec4f           c4f;
+  BaseImporter::VHandles    vhandles;
+  VertexHandle              vh;
+  std::stringstream         stream;
+  std::string               trash;
 
   // read header line
   std::string header;
@@ -227,13 +229,12 @@ _OFFReader_::read_ascii(std::istream& _in, BaseImporter& _bi, Options& _opt) con
 
     int colorType = getColorType(line, options_.vertex_has_texcoord() );
 
-    std::stringstream stream( line );
+    stream.str(line);
+    stream.clear();
 
     //perhaps read COLOR
     if ( options_.vertex_has_color() ){
 
-      std::string trash;
-
       switch (colorType){
         case 0 : break; //no color
         case 1 : stream >> trash; break; //one int (isn't handled atm)
@@ -315,9 +316,8 @@ _OFFReader_::read_ascii(std::istream& _in, BaseImporter& _bi, Options& _opt) con
 
       int colorType = getColorType(line, false );
 
-      std::stringstream stream( line );
-
-      std::string trash;
+      stream.str(line);
+      stream.clear();
 
       switch (colorType){
         case 0 : break; //no color

src/OpenMesh/Core/IO/reader/STLReader.cc

@@ -249,6 +249,9 @@ read_stla(std::istream& _in, BaseImporter& _bi, Options& _opt) const
 
   std::string line;
 
+  std::string        garbage;
+  std::stringstream  strstream;
+
   bool facet_normal(false);
 
   while( _in && !_in.eof() ) {
@@ -265,9 +268,8 @@ read_stla(std::istream& _in, BaseImporter& _bi, Options& _opt) const
 
     // Normal found?
     if (line.find("facet normal") != std::string::npos) {
-      std::stringstream strstream(line);
-
-      std::string garbage;
+      strstream.str(line);
+      strstream.clear();
 
       // facet
       strstream >> garbage;
@@ -292,9 +294,9 @@ read_stla(std::istream& _in, BaseImporter& _bi, Options& _opt) const
         std::getline(_in, line);
         trimStdString(line);
 
-        std::stringstream strstream(line);
+        strstream.str(line);
+        strstream.clear();
 
-        std::string garbage;
         strstream >> garbage;
 
         strstream >> v[0];