On Wednesday, 27 September 2017 at 19:55:07 UTC, nkm1 wrote:
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.
I mean to an extent I agree, but I moved from using GLfloat
arrays for matrix's to a Matrix object to aid in Matrix math like
multiplication, so I have to go through my code and in many
places change it to using matrix.ptr, considering that I have to
do this for every object in a scene multiple times for the
translation, scale, projection and etc matrix's it's more
tedious, and I'm the only one working on the code and I comment
and document my code a lot. If one thing annoys m e about
language design, it's when peoples actions dictate the decisions
of the language, it shouldn't be the responsibility of the
language to limit users in order to prevent bad habits or
practices, it should be the responsibility of education to do so.
The attitude of "some people use this feature incorrectly, so
let's ban it's use entirely" is honestly ridiculous to me, but oh
well, that's apparently the modern philosophy.
