On Wednesday, 27 September 2017 at 16:35:54 UTC, DreadKyller
wrote:
Been using D for a couple years now, however one problem I've
had, more so recently since I've been dealing a lot with OpenGL
is related to pointers.
I have a matrix object to aid with the matrix math required for
working with 3D transforms. However OpenGL (I'm using
DerelictGL3 bindings) requires pointers to the data. I am
currently doing the following:
Matrix!float ortho(float l, float r, float b, float t, float f,
float n = -1)
{
Matrix!float oMat = identity(); // Get default Identity Matrix
oMat[0,0] = 2 / (r - l);
oMat[1,1] = 2 / (t - b);
oMat[2,2] = -2 / (f - n);
oMat[3] = [-(r+l)/(r-l), -(t+b)/(t-b), -(f+n)/(f-n), 1];
return oMat;
}
And then to use with OpenGL (passing as uniform into shader):
glUniformMatrix4fv(transform_uniform, 1, GL_FALSE, matrix.addr
);
where addr is a property that returns the address of the first
item in the Matrix's internal data. I know I can also use
&matrix[0][0]
My question is about overloading, several operators can be
overloaded in D, one of the ones that can't apparently is the
address of operator (&object). My question is have I simply
missed it or does it actually not exist, and if it's not
overloadable, is there any reason why this was decided? Because
there's been numerous times that it'd be useful to me, just
recently with how much I use the operator because of OpenGL I
decided to ask.
& is not overloadable, presumably because some people were
annoyed by abuse of operator overloading in C++. The reason is to
improve readability (of other people's code).
Just rename matrix.addr to matrix.ptr... like in arrays:
https://dlang.org/spec/arrays.html#array-properties
That would be clearer (opinion), since the reader of your code
can assume that matrix.ptr does the same thing with your matrix
as array.ptr does with arrays. OTOH, overloading &matrix to do
something different from built in &matrix seems like a pointless
obfuscation to me.
