What are vectors?

First, let's do a quick refresh on vectors and the way you can use Cocos2d-x to deal with them.

So what is the difference between a vector and a point? At first, they seem to be the same. Consider the following point and vector:

• Point (2, 3.5)
• Vec2 (2, 3.5)

The following figure illustrates a point and a vector:

In this figure, they each have the same value for x and y. So what's the difference?

With a vector, you always have extra information. It is as if, besides those two values for x and y, we also have the x and y of the vector's origin, which in the previous figure we can assume to be point (0, 0). So the vector is moving in the direction described from point (0, 0) to point (2, 3.5). The extra information we can derive then from vectors is direction and length (usually referred to as magnitude).

It's as if a vector is a person's stride. We know how long each step is, and we know the direction in which the person is walking.

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