[SOLVED] Can't pass vec3 to externed function

[joseph.howell]

Hey, I'm trying to create a function in c++ and export it to UnigineScript.  I'm trying to follow the "dot" example you have in the documentation.  But I can't get it to work after trying lots of things.

 

The function is defined something like this:

 

void someFunc(const vec3 &a, vec3 &b, vec3 &cl)

 

I am exporting it like this:

 

Interpreter::addExternFunction("someFunc", MakeExternFunction(&someFunc));

 

 

Then I call it in script like this:

 

vec3 a, b, c;

someFunc(a, b, c);

 

But I get this error message:

 

camera_control.h:222: Variable::getExternClassObject(): can't convert vec3 to struct Unigine::Math::vec3 * __ptr64

 

What am I doing wrong?

 

 

[ded]

Hi,

 

Conversion from "Variable" to "vec3 &" is not defined.

There are defined conversions for "vec3" and "const vec3 &".

So I suppose signature of your function should be:

void someFunc(const vec3 &a, const vec3 &b, const vec3 &c).

[joseph.howell]

Is there no pass by reference then?  I wanted to be able to pass a couple of vec3s back out.

[ded]

Hi,

I'm afraid not.
There is workaround however: you can pass reference to an instance of extern class.

class VectorPair {
public:
    vec3 a;
    vec3 b;
    
    vec3 getA() const { return a; }
    vec3 getB() const { return b; }
};

void foo(const Variable &v) {
    VectorPair &ret = v.getExternClassObjectRef<VectorPair>(Interpreter::get());
    ret.a = vec3(1,2,3);
    ret.b = vec3(4,5,6);
}

...

ExternClass<VectorPair> *c = MakeExternClass<VectorPair>();
c->addConstructor();
c->addFunction("getA",&VectorPair::getA);
c->addFunction("getB",&VectorPair::getB);
Interpreter::addExternClass("VectorPair",c);

Interpreter::addExternFunction("foo",MakeExternFunction(&foo));

[joseph.howell]

Ok, thanks