Question

struct vect{
    float x,y,z;
    vect(float xx, float yy, float zz){
        x=xx;
        y=yy;
        z=zz;
    }
    vect(){
        x=0;
        y=0;
        z=0;
    }
    void normalize(){
        float len = sqrt(x*x + y*y + z*z);
        x = x/len;
        y = y/len;
        z = z/len;
    }
    vect operator-(const vect &other) const{return vect(x-other.x,y-other.y,z-other.z);}
};

bool tri_plane_x(vect *v1, vect *v2, vect *v3, vect *pos, float s){

    //removed unnessecary code

    if (vv1 != vv2){
        vect dir = v2 - v1; // getting an error on this line
        dir.normalize();
        float d = (pos->x - v1->x)/dir.x;
        hy[c] = d * dir.y + v1->y;
        hz[c] = d * dir.z + v1->z;
        c++;
    }

    //removed unnessecary code
}

do some one know why this wont compile? is there a error in how i overloaded the function or is this because i am subtracting two pointers to a vect?

./exporter/main.cpp:74:19: error: conversion from ‘long int’ to non-scalar type ‘vect’ requested

here is the compiler error related to this line. (didn’t include the whole log as it is just a the same error repeated many times in the code)

i can’t see where the “long int” comes from… is there another way of overloading when using pointers?

Answer 1

v2 and v1 are pointers, the difference between two pointers is a number telling you the offset between two addresses, which is a number.

You don’t want to “overload using pointers” you want the result of operator- on the objects pointed to, not on the pointers themselves.

You need to say *v2 - *v1 to dereference the pointers and access the objects they point to.