Irrlicht Engine

I was just curious as to why S3DVertex, S3DVertex2TCoords and S3dVertexTangents were all made separate structs. Wouldn't it be simpler if S3dVertex was a base class, from which the other two were derived?

For example, in the constructor for CTriangleSelector, there's a switch statement for a ...

I seem to have stumbled across a few undefined functions in line2d.h.

intersectWith() calls both getInterSectionOfLines() and isPointBetweenPoints() , neither of which are defined elsewhere in line2d.h, nor anywhere else I can find. I searched the forum for these names and came up with a few posts ...

When the derived class is constructed, the base class's constructor is also called. Since there is no CTriangleSelector(void) constructor, the compiler doesn't know what to pass into the bass class's constructor.

Pretty much what I had figured, but that's what's confusing me. ITriangleSelector ...

Well, this alone will produce that error:

#include <CTriangleSelector.h>
#include <IMesh.h>
#include <ISceneNode.h>

class UVTriangleSelector : public CTriangleSelector
{
public:
UVTriangleSelector( IMesh* mesh, ISceneNode* node ) {};
};

I have an implimentation for the above constructor, but ...

I'm trying to create a sub-class of CTriangleSelector which will create an array of my own triangle3df sub-class. Essentially, all I'm doing (so far) is overriding the (IMesh* mesh, ISceneNode* node) constructor. However, when I try to compile, I get this error:

no matching function for call to ...