Use "custom" sin and cos in glm::rotate

Question

Is there any way of using my own sin and cos functions instead of ::std::sin and ::std::cos in glm::rotate(...) calls?

The only way I can think of, is using macros to replace the sin and cos symbols inside the std namespace, but I really wouldn't like to do that.

Answer 1

Using LD preload will work.

I will explain with a small example.

Assume that this is our main code...

int main()
{
   std::cout<< std::sin(1000);
   return 0;
}

if I compile and run it, it should print 0.82688

Now I define my own sin

mysin.hpp

extern "C"
{
    double sin(double);
}

mysin.cpp

#include "mysin.hpp"

double sin(double in)
{
    return in + 10;//do you computation here
}

Now compile it as a shared lib

g++ -O2 -c -fPIC mysin.cpp -o mysin.o
g++ -shared -Wl,-soname,libmysin.so mysin.o -o libmysin.so

Assuming original program is compiled as "a.out". Run it with our lib preloaded

LD_PRELOAD=./libmysin.so ./a.out

Now the result will be "1010".