The second part is that the math is simple with circles.
Those two things make it a good choice for many situations, and a good building block in many of the rest.
To demonstrate this type of collision detection I will create a two player game of Pong. To get started, create a new XNA game called Bounding Box Collision. This will reduce the amount of code that you write. This game is in 2D so I needed a Texture2D for the game object. For the same reason, I have a Vector2 for the velocity of the object in the game.
What this means is that instead of moving an object 2 pixels or 3 pixels you can move an object 2.5 pixels. The property Bounding Box returns a Rectangle that describes the game object.
I will be writing more than 300 articles for this series.
In this tutorial, we will cover the basics to get you going with collision detection.
To deal with this problem, game programmers will use an approximation of the model that is easier to check for collisions.
The two methods that are most commonly used are bounding boxes and bounding spheres.
Instead, I decided to auto calculate all the bounding boxes.
To better illustrate this, take a look at the following animation: Notice how the red portion (bounding box) automatically re-sizes based on the current frame of the animation.