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## General => Feedback => Topic started by: gameCloner on February 16, 2013, 03:18:59 pm

Title: Issues with general purpose of SimpleVector Class
Post by: gameCloner on February 16, 2013, 03:18:59 pm
Hi Helge and the jpct community.

first of all i would excuse me caus im no an expert poster, so i ask you to be kind in teaching me some.

im trying to code a ball game like tilt. im posting it soon if i can omn the forum.

i came across some code errors

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`SimpleVector copy = globalPos; updateGlobalPos();  // or updateGlobalPos(globalPos) `this code affects copy as well. I understood i can not assign vectors as strings. To me it could be better to have a clone() and a equals() method in class.
example 2:
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`float maxKnot = 12.f;public void interpolate(SimpleVector p1, SimpleVector p2){ SimpleVector delta = new SimpleVector(p1.x,p1.y,p1.z); delta.sub(p2); for ( int i = maxKnot ; i >0 ; i--){ SimpleVector temp= new SimpleVector(delta.x,delta.y,delta.z); temp.scalarMul( i  / maxKnot); temp.add(p2); points.add(temp); } }`to me that should look like this:
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`public void interpolate(SimpleVector p1, SimpleVector p2){      p1.sub(p2);      for ( int i = maxKnot ; i >0 ; i--){ SimpleVector delta = p1.clone().scalarMul( alfa ).add(p2);                points.add( delta );`
it could be far better if we can add vectors the math style, as in c++ or as vertexShaders code.

Title: Re: Issues with general purpose of SimpleVector Class
Post by: EgonOlsen on February 16, 2013, 05:26:09 pm
I don't get what you mean with your first example? You want to assign the content of globalPos to copy? Or create a copy of it? You can do both in several ways:

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`SimpleVector copy=new SimpleVector(globalPos);..or...SimpleVector copy= SimpleVector.create(globalPos);..or to set it:copy.set(globalPos);`
equals() is implemented for SimpleVector.

You can't add SimpleVector (or anything except primitives and strings in Java) in math style, because there's no operator overloading in the language (thank god...).

I see your point, but if i would make all methods return the instance to concatenate their calls, nobody would be able to distinguish if that call creates a new instance or just returns "this". As it is now, if a method of SimpleVector returns a SimpleVector, you can be sure that it's a new instance. There are variants for add and sub called calcSub and calcAdd that return a new instance instead of working on "this".

Title: Re: Issues with general purpose of SimpleVector Class
Post by: gameCloner on February 17, 2013, 06:10:25 pm
You ve been clear.
I still cannot code as I usually do.
but I can bear with, every other one can bear with that, so I.

Thanks and be well.
Title: Re: Issues with general purpose of SimpleVector Class
Post by: EgonOlsen on February 17, 2013, 09:40:34 pm