BGE patch: KX_GameObject::rayCast() improvements to have X-Ray option, return true face normal and hit polygon information.

rayCast(to,from,dist,prop,face,xray,poly):

The face paremeter determines the orientation of the normal: 
  0 or omitted => hit normal is always oriented towards the ray origin (as if you casted the ray from outside)
  1 => hit normal is the real face normal (only for mesh object, otherwise face has no effect)
The ray has X-Ray capability if xray parameter is 1, otherwise the first object hit (other than self object) stops the ray.
The prop and xray parameters interact as follow:
    prop off, xray off: return closest hit or no hit if there is no object on the full extend of the ray.
    prop off, xray on : idem.
    prop on,  xray off: return closest hit if it matches prop, no hit otherwise.
    prop on,  xray on : return closest hit matching prop or no hit if there is no object matching prop on the full extend of the ray.
if poly is 0 or omitted, returns a 3-tuple with object reference, hit point and hit normal or (None,None,None) if no hit.
if poly is 1, returns a 4-tuple with in addition a KX_PolyProxy as 4th element.

The KX_PolyProxy object holds information on the polygon hit by the ray: the index of the vertex forming the poylgon, material, etc.

Attributes (read-only):
 matname: The name of polygon material, empty if no material.
 material: The material of the polygon
 texture: The texture name of the polygon.
 matid: The material index of the polygon, use this to retrieve vertex proxy from mesh proxy
 v1: vertex index of the first vertex of the polygon, use this to retrieve vertex proxy from mesh proxy
 v2: vertex index of the second vertex of the polygon, use this to retrieve vertex proxy from mesh proxy
 v3: vertex index of the third vertex of the polygon, use this to retrieve vertex proxy from mesh proxy
 v4: vertex index of the fourth vertex of the polygon, 0 if polygon has only 3 vertex
     use this to retrieve vertex proxy from mesh proxy
 visible: visible state of the polygon: 1=visible, 0=invisible
 collide: collide state of the polygon: 1=receives collision, 0=collision free.
Methods:
 getMaterialName(): Returns the polygon material name with MA prefix
 getMaterial(): Returns the polygon material
 getTextureName(): Returns the polygon texture name
 getMaterialIndex(): Returns the material bucket index of the polygon. 
 getNumVertex(): Returns the number of vertex of the polygon.
 isVisible(): Returns whether the polygon is visible or not
 isCollider(): Returns whether the polygon is receives collision or not
 getVertexIndex(vertex): Returns the mesh vertex index of a polygon vertex
 getMesh(): Returns a mesh proxy

New methods of KX_MeshProxy have been implemented to retrieve KX_PolyProxy objects:
 getNumPolygons(): Returns the number of polygon in the mesh.
 getPolygon(index): Gets the specified polygon from the mesh.

More details in PyDoc.

source/gameengine/Physics/Bullet/CcdPhysicsController.h

@@ -75,6 +75,16 @@ public:
 	{
 		return m_nextShape;
 	}
+	CcdShapeConstructionInfo* GetChildShape(int i)
+	{
+		CcdShapeConstructionInfo* shape = m_nextShape;
+		while (i > 0 && shape != NULL)
+		{
+			shape = shape->m_nextShape;
+			i--;
+		}
+		return shape;
+	}
 
 	bool SetMesh(RAS_MeshObject* mesh, bool polytope);
 
@@ -89,6 +99,11 @@ public:
 	std::vector<btPoint3>	m_vertexArray;	// Contains both vertex array for polytope shape and
 											// triangle array for concave mesh shape.
 											// In this case a triangle is made of 3 consecutive points
+	std::vector<int>		m_polygonIndexArray;	// Contains the array of polygon index in the 
+													// original mesh that correspond to shape triangles.
+													// only set for concave mesh shape.
+	const RAS_MeshObject*	m_meshObject;	// Keep a pointer to the original mesh 
+
 protected:
 	CcdShapeConstructionInfo* m_nextShape;	// for compound shape
 	int						m_refCount;		// this class is shared between replicas