class Vec3 {
public:
float x, y, z;
public:
///operators, methods go here
...
}
Whats the best way of doing this?
Author
Hey,
I have a Vector class which looks something like this:
Floats are 4-bytes long, so on any relatively sane platform they will be tightly packed. So yes, declare an operator float () which returns a pointer to x, and it will be called automatically:
class vector{public: float x, y, z;public: operator float *() {return &x;}};vector v1;glVertex3fv(v1);
Another way is to use non-standard extensions as the nameless union:
This is what I use on MS Visual C++. Greetz,
Illco
class Vector3{public: union { // A struct makes sure x, y and z don't share the same memory of the union struct { float m_x, m_y, m_z; } // The array uses the same memory as the struct float m_elements[3]; }};This is what I use on MS Visual C++. Greetz,
Illco
If you use swifcoder's code, you should at least make them GLfloats instead of floats, because GLfloats are guaranteed to be four bytes. If it was me though, I would just store the x, y, and z in an array.
Quote:Original post by Illco
Another way is to use non-standard extensions as the nameless union...
Or use the standard compliant & portable solution
Quote:Original post by Simian Man
If you use swifcoder's code, you should at least make them GLfloats instead of floats, because GLfloats are guaranteed to be four bytes. If it was me though, I would just store the x, y, and z in an array.
If they are IEEE floats then they are 4 bytes, so I would not worry about the above quote.
As for swiftcoder's code I would add another operator
operator float const*() {return &x;}Quote:Original post by snk_kidQuote:Original post by Illco
Another way is to use non-standard extensions as the nameless union...
Or use the standard compliant & portable solution
By Gosh! Brilliant!
Quote:Original post by Anonymous Poster
As for swiftcoder's code I would add another operator
*** Source Snippet Removed ***
i'd prefer:
struct vector { float x, y, z; typedef float (&array_ref)[3]; typedef const float (&const_array_ref)[3]; //.... operator array_ref() { return reinterpret_cast<array_ref>(*this); } operator const_array_ref() const { return reinterpret_cast<const_array_ref>(*this); }};But that is being abit too pedantic.
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