Using class variables into class function

Programming Questions

3veduardo

Using class variables into class function

in Programming Questions • 1 year ago

Hi all,

I'm new at the forum but I already try to find an answer for my question searching on it.

I have the next problem. I have a class with a PVector variable who is created in constructor. In the same class I have a function that calls to the variable, but I take an error saying: "cannot convert from void to PVector" referring to line 28.

the code:

class Segmento {
PVector puntoA, puntoB;
Segmento(float t_Ax, float t_Ay, float t_Bx, float t_By) { //constructor con puntos
this.puntoA = new PVector(t_Ax, t_Ay);
this.puntoB = new PVector(t_Bx, t_By);
}
Segmento(PVector t_A, PVector t_B) { //constructor con PVectores
this.puntoA=t_A;
this.puntoB=t_B;
}
void dibuja(color c_stro, int t_stro) { //dibjua y define color y grosor
strokeWeight(t_stro);
stroke(c_stro);
line(puntoA.x, puntoA.y, puntoB.x, puntoB.y);
}
int distancia (float desdeX, float desdeY) {
PVector puntoext;
puntoext=new PVector (desdeX, desdeY);
PVector puntoP;
PVector puntoAux1;
PVector puntoAux2;
float valaux1;
puntoAux1= puntoB.sub(puntoA);
puntoAux2= puntoext.sub(this.puntoA);
valaux1=(puntoAux1.dot(puntoAux2))/(puntoAux1.dot(puntoAux1));
puntoP= puntoA.add(puntoAux1.mult(valoraux1));
if (valaux1>0 && valaux1<1) return puntoext.dist(puntoP);
if (valaux1<=0) return puntoext.dist(puntoA);
if (valaux1>=1) return puntoext.dist(puntoB);
}
}

someone could give me a hand.

Thank You all.

Replies(2)

Jonny Stu..

Re: Using class variables into class function

1 year ago

When you do something like:

puntoB.sub(puntoA)

This modifies puntoB in place and returns void (nothing) so you can't then assign it to a new PVector (which is why you're getting your error). There's a static method equivalent in the PVector class that you can use it you need a new PVector to work on.

puntoAux1= PVector.sub(puntoB, puntoA);

The same is true for .add() and .mult().

3veduardo

Re: Using class variables into class function

1 year ago

Thank you very much.

It works perfectly.

I missjudged the problem.

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