Nasal cppbindings: automatic conversion of vec2 to/from Nasal

simgear/canvas/CanvasEventListener.cxx

@@ -52,7 +52,7 @@ namespace canvas
     _sys.lock()->gcRelease(_gc_key);
   }
 
-  //------------------------------------------------------------------------------
+  //----------------------------------------------------------------------------
   void EventListener::call(const canvas::EventPtr& event)
   {
     SystemAdapterPtr sys = _sys.lock();

simgear/canvas/elements/CanvasText.cxx

@@ -37,7 +37,7 @@ namespace canvas
       void setFill(const std::string& fill);
       void setBackgroundColor(const std::string& fill);
 
-      osg::Vec2 handleHit(float x, float y);
+      osg::Vec2 handleHit(const osg::Vec2f& pos);
 
       virtual osg::BoundingBox computeBound() const;
 
@@ -79,13 +79,13 @@ namespace canvas
   }
 
   //----------------------------------------------------------------------------
-  osg::Vec2 Text::TextOSG::handleHit(float x, float y)
+  osg::Vec2 Text::TextOSG::handleHit(const osg::Vec2f& pos)
   {
     float line_height = _characterHeight + _lineSpacing;
 
     // TODO check with align other than TOP
     float first_line_y = -0.5 * _lineSpacing;//_offset.y() - _characterHeight;
-    size_t line = std::max<int>(0, (y - first_line_y) / line_height);
+    size_t line = std::max<int>(0, (pos.y() - first_line_y) / line_height);
 
     if( _textureGlyphQuadMap.empty() )
       return osg::Vec2(-1, -1);
@@ -102,7 +102,7 @@ namespace canvas
     const float character_width = getCharacterHeight()
                                 * getCharacterAspectRatio();
 
-    y = (line + 0.5) * line_height;
+    float y = (line + 0.5) * line_height;
 
     bool line_found = false;
     for(size_t i = 0; i < line_numbers.size(); ++i)
@@ -132,20 +132,21 @@ namespace canvas
                       + HIT_FRACTION * glyphs[i]->getHorizontalAdvance()
                                      * character_width;
 
-      if( x <= threshold )
+      if( pos.x() <= threshold )
       {
+        osg::Vec2 hit(0, y);
         if( i == 0 || line_numbers[i - 1] != line )
           // first character of line
-          x = coords[i * 4].x();
+          hit.x() = coords[i * 4].x();
         else if( coords[(i - 1) * 4].x() == coords[(i - 1) * 4 + 2].x() )
           // If previous character width is zero set to begin of next character
           // (Happens eg. with spaces)
-          x = coords[i * 4].x();
+          hit.x() = coords[i * 4].x();
         else
           // position at center between characters
-          x = 0.5 * (coords[(i - 1) * 4 + 2].x() + coords[i * 4].x());
+          hit.x() = 0.5 * (coords[(i - 1) * 4 + 2].x() + coords[i * 4].x());
 
-        return osg::Vec2(x, y);
+        return hit;
       }
     }
 
@@ -266,26 +267,9 @@ namespace canvas
 #endif
 
   //----------------------------------------------------------------------------
-  void Text::childChanged(SGPropertyNode* child)
+  osg::Vec2 Text::getNearestCursor(const osg::Vec2& pos) const
   {
-    if( child->getParent() != _node )
+    return _text->handleHit(pos);
-      return;
-
-    const std::string& name = child->getNameString();
-    if( name == "hit-y" )
-      handleHit
-      (
-        _node->getFloatValue("hit-x"),
-        _node->getFloatValue("hit-y")
-      );
-  }
-
-  //----------------------------------------------------------------------------
-  void Text::handleHit(float x, float y)
-  {
-    const osg::Vec2& pos = _text->handleHit(x, y);
-    _node->setFloatValue("cursor-x", pos.x());
-    _node->setFloatValue("cursor-y", pos.y());
   }
 
 } // namespace canvas

simgear/canvas/elements/CanvasText.hxx

@@ -43,15 +43,13 @@ namespace canvas
       void setFont(const char* name);
       void setAlignment(const char* align);
 
+      osg::Vec2 getNearestCursor(const osg::Vec2& pos) const;
+
     protected:
 
       class TextOSG;
       osg::ref_ptr<TextOSG> _text;
 
-      virtual void childChanged(SGPropertyNode * child);
-
-      void handleHit(float x, float y);
-
   };
 
 } // namespace canvas

simgear/math/SGVec2.hxx

@@ -18,6 +18,10 @@
 #ifndef SGVec2_H
 #define SGVec2_H
 
+#include "SGLimits.hxx"
+#include "SGMathFwd.hxx"
+#include "SGMisc.hxx"
+
 #include <iosfwd>
 
 /// 2D Vector Class

simgear/nasal/cppbind/CMakeLists.txt

@@ -5,6 +5,7 @@ set(HEADERS
   NasalHash.hxx
   from_nasal_detail.hxx
   from_nasal.hxx
+  nasal_traits.hxx
   to_nasal.hxx
 )
 

simgear/nasal/cppbind/cppbind_test.cxx

@@ -1,3 +1,5 @@
+#include <simgear/math/SGVec2.hxx>
+
 #include "Ghost.hxx"
 #include "NasalHash.hxx"
 
@@ -73,8 +75,15 @@ int main(int argc, char* argv[])
   VERIFY( naNumValue(r).num == 4.2f );
   VERIFY( from_nasal<float>(c, r) == 4.2f );
 
-  std::vector<int> vec;
+  float test_data[3] = {0, 4, 2};
+  r = to_nasal(c, test_data);
+
+  SGVec2f vec(0,2);
   r = to_nasal(c, vec);
+  VERIFY( from_nasal<SGVec2f>(c, r) == vec );
+
+  std::vector<int> std_vec;
+  r = to_nasal(c, std_vec);
 
   r = to_nasal(c, "string");
   try
@@ -177,6 +186,9 @@ int main(int argc, char* argv[])
   VERIFY( cc.getArg<std::string>(0) == "test-arg" );
   VERIFY( cc.getArg<std::string>(1) == "" );
 
+  naRef args_vec = nasal::to_nasal(c, args);
+  VERIFY( naIsVector(args_vec) );
+
   // TODO actually do something with the ghosts...
 
   naFreeContext(c);

simgear/nasal/cppbind/from_nasal_detail.hxx

@@ -20,6 +20,8 @@
 #ifndef SG_FROM_NASAL_DETAIL_HXX_
 #define SG_FROM_NASAL_DETAIL_HXX_
 
+#include "nasal_traits.hxx"
+
 #include <simgear/nasal/nasal.h>
 
 #include <boost/utility/enable_if.hpp>
@@ -112,6 +114,20 @@ namespace nasal
     return vec;
   }
 
+  /**
+   * Convert a Nasal vector of 2 elements to a 2d vector
+   */
+  template<class Vec2>
+  typename boost::enable_if<is_vec2<Vec2>, Vec2>::type
+  from_nasal_helper(naContext c, naRef ref, Vec2*)
+  {
+    std::vector<double> vec =
+      from_nasal_helper(c, ref, static_cast<std::vector<double>*>(0));
+    if( vec.size() != 2 )
+      throw bad_nasal_cast("Expected vector with two elements");
+    return Vec2(vec[0], vec[1]);
+  }
+
 } // namespace nasal
 
 #endif /* SG_FROM_NASAL_DETAIL_HXX_ */

simgear/nasal/cppbind/to_nasal.cxx

@@ -29,6 +29,12 @@ namespace nasal
     return ret;
   }
 
+  //----------------------------------------------------------------------------
+  naRef to_nasal(naContext c, const char* str)
+  {
+    return to_nasal(c, std::string(str));
+  }
+
   //----------------------------------------------------------------------------
   naRef to_nasal(naContext c, naCFunction func)
   {

simgear/nasal/cppbind/to_nasal.hxx

@@ -20,6 +20,8 @@
 #ifndef SG_TO_NASAL_HXX_
 #define SG_TO_NASAL_HXX_
 
+#include "nasal_traits.hxx"
+
 #include <simgear/nasal/nasal.h>
 
 #include <boost/utility/enable_if.hpp>
@@ -37,6 +39,12 @@ namespace nasal
    */
   naRef to_nasal(naContext c, const std::string& str);
 
+  /**
+   * Convert C-string to Nasal string
+   */
+  // We need this to prevent the array overload of to_nasal being called
+  naRef to_nasal(naContext c, const char* str);
+
   /**
    * Convert function pointer to Nasal function
    */
@@ -62,6 +70,19 @@ namespace nasal
     return naNum(num);
   }
 
+  /**
+   * Convert a fixed size array to a Nasal vector
+   */
+  template<class T, size_t N>
+  naRef to_nasal(naContext c, const T(&array)[N])
+  {
+    naRef ret = naNewVector(c);
+    naVec_setsize(c, ret, N);
+    for(size_t i = 0; i < N; ++i)
+      naVec_set(ret, i, to_nasal(c, array[i]));
+    return ret;
+  }
+
   /**
    * Convert std::vector to Nasal vector
    */
@@ -83,6 +104,19 @@ namespace nasal
     return ret;
   }
 
+  /**
+   * Convert a 2d vector to Nasal vector with 2 elements
+   */
+  template<class Vec2>
+  typename boost::enable_if<is_vec2<Vec2>, naRef>::type
+  to_nasal(naContext c, const Vec2& vec)
+  {
+    // We take just double because in Nasal every number is represented as
+    // double
+    double nasal_vec[2] = {vec[0], vec[1]};
+    return to_nasal(c, nasal_vec);
+  }
+
 } // namespace nasal
 
 #endif /* SG_TO_NASAL_HXX_ */