Bringing across Region enhancements from Cubiquity branch.

library/PolyVoxCore/include/PolyVoxCore/Region.h

@@ -74,6 +74,12 @@ namespace PolyVox
 		/// Inequality Operator.
         bool operator!=(const Region& rhs) const;
 
+		/// Gets the 'x' position of the centre.
+		int32_t getCentreX(void) const;
+		/// Gets the 'y' position of the centre.
+		int32_t getCentreY(void) const;
+		/// Gets the 'z' position of the centrer.
+		int32_t getCentreZ(void) const;
 		/// Gets the 'x' position of the lower corner.
 		int32_t getLowerX(void) const;
 		/// Gets the 'y' position of the lower corner.
@@ -87,6 +93,8 @@ namespace PolyVox
 		/// Gets the 'z' position of the upper corner.
 		int32_t getUpperZ(void) const;
 
+		/// Gets the centre of the region
+		Vector3DInt32 getCentre(void) const;
 		/// Gets the position of the lower corner.
 		Vector3DInt32 getLowerCorner(void) const;
 		/// Gets the position of the upper corner.
@@ -202,6 +210,9 @@ namespace PolyVox
 		int32_t m_iUpperZ;
 	};
 
+	// Non-member functions
+	bool intersects(const Region& a, const Region& b);
+
 	// Non-member overloaded operators. 
 	/// Stream insertion operator.
 	std::ostream& operator<<(std::ostream& os, const Region& region);
@@ -210,6 +221,30 @@ namespace PolyVox
 	// 'inline' keyword is used for the definition rather than the declaration.
 	// See also http://www.parashift.com/c++-faq-lite/inline-functions.html
 
+	/**
+	 *  \return The 'x' position of the centre.
+	 */
+	inline int32_t Region::getCentreX(void) const
+	{
+		return (m_iLowerX + m_iUpperX) / 2;
+	}
+
+	/**
+	 *  \return The 'y' position of the centre.
+	 */
+	inline int32_t Region::getCentreY(void) const
+	{
+		return (m_iLowerY + m_iUpperY) / 2;
+	}
+
+	/**
+	 *  \return The 'z' position of the centre.
+	 */
+	inline int32_t Region::getCentreZ(void) const
+	{
+		return (m_iLowerZ + m_iUpperZ) / 2;
+	}
+
 	/**
 	 *  \return The 'x' position of the lower corner.
 	 */
@@ -258,6 +293,14 @@ namespace PolyVox
 		return m_iUpperZ;
 	}
 
+	/**
+	 *  \return The position of the lower corner.
+	 */
+	inline Vector3DInt32 Region::getCentre(void) const
+	{
+		return Vector3DInt32(getCentreX(), getCentreY(), getCentreZ());
+	}
+
 	/**
 	 *  \return The position of the lower corner.
 	 */

library/PolyVoxCore/source/Region.cpp

@@ -150,12 +150,12 @@ namespace PolyVox
 			&&  (m_iUpperX == rhs.m_iUpperX) && (m_iUpperY == rhs.m_iUpperY) && (m_iUpperZ == rhs.m_iUpperZ));
     }
 
-	////////////////////////////////////////////////////////////////////////////////
+	/**
-	/// Two regions are considered different if any of their extents differ.
+	 *  Two regions are considered different if any of their extents differ.
-	/// \param rhs The Region to compare to.
+	 *  \param rhs The Region to compare to.
-    /// \return true if the Regions are different.
+     *  \return true if the Regions are different.
-    /// \sa operator==
+     *  \sa operator==
-	////////////////////////////////////////////////////////////////////////////////
+	 */
     bool Region::operator!=(const Region& rhs) const
     {
 		return !(*this == rhs);
@@ -488,6 +488,21 @@ namespace PolyVox
 		shrink(v3dAmount.getX(), v3dAmount.getY(), v3dAmount.getZ());
 	}
 
+	/**
+	 * This function only returns true if the regions are really intersecting and not simply touching.
+	 */
+
+	bool intersects(const Region& a, const Region& b)
+	{
+		// No intersection if seperated along an axis.
+		if(a.getUpperX() < b.getLowerX() || a.getLowerX() > b.getUpperX()) return false;
+		if(a.getUpperY() < b.getLowerY() || a.getLowerY() > b.getUpperY()) return false;
+		if(a.getUpperZ() < b.getLowerZ() || a.getLowerZ() > b.getUpperZ()) return false;
+
+		// Overlapping on all axes means Regions are intersecting.
+		return true;
+	}
+
 	/**
      * Enables the Region to be used intuitively with output streams such as cout.
      * \param os The output stream to write to.