Type conversion question.

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10-16-2006
ellis

Type conversion question.

Hi,
I've been studying gamedev for 2 months now. We use RenderWare at school. RenderWare is written in C, but we use C++. I've now come to see how a mix like that don't always work out as one would like.

RenderWare uses there own types for vectors, matrices and so on. I would like to use my own classes for that, cuz seriously, how can some one stand doing complex math formulas with functions like RwV3dAdd, RwV3dSub, RwV3dCrossProduct, and RwV3dDotProduct, where all functions take a RwV3d pointer as its first argument as the target.

My classes uses operator overloads to do all of that in a clean fashion.

My question is now. In the end, i will always have to use a RenderWare function to do certain things. I wonder if its possible to give a function which needs the type 'RWType', a completely different type, which would be converted when passed to this function i cant change ?

I hope you understand what i meen =P

Thx
10-16-2006
Perspective

You could just write wrappers for the renderware functions and overload those operators.
10-16-2006
Tonto

It is probably smart to write wrappers, but you but also write an operator RWType ().
10-17-2006
jafet

You could have a member function (say get_raw()) return a reference to the innards of the class and pass this innard to the functions; whether you think this violates encapsulation is left for you to decide. GMP 4's C++ wrapper does it though.
10-17-2006
ellis

I went for the 'operator RwV3d()' and 'operator RwV3d*()' way.
Cuz my constructors can take both RwV3d and RwV3d* as a parameter (like RwV3d to CVector3 conversion).
This gives me the freedom to convert back and forth the two types without me ever having to actually think about it.

If i want, i could even make it go so far as making math operators work with both RwV3d and CVector3. (not gonna do that tho =P)

CVector3 is my own vector class based on RW functions, and RwV3d is RWs vector (a struct with 3 floats).

Anyways... thanks for all the feedback. Helped me alot.
10-17-2006
ChaosEngine

Quote:

Originally Posted by ellis

I went for the 'operator RwV3d()' and 'operator RwV3d*()' way.
Cuz my constructors can take both RwV3d and RwV3d* as a parameter (like RwV3d to CVector3 conversion).
This gives me the freedom to convert back and forth the two types without me ever having to actually think about it.

be very wary of implicit conversions. They can bite you in the bum when you least expect it. IMO, it is good practice to use explicit constructors for conversions. I also like to write small inline casting template functions to convert from class types to others.