Texture2D.Bounds.Intersect, but the Bounds never move? - XNA, .Net 4.0

Question

Hi all, I am still shiny new to XNA, so please forgive any stupid question and statements in this post (The added issue is that I am using Visual Studio 2010 with .Net 4.0 which also means very few examples exist out on the web - well, none that I could find easily):

I have two 2D objects in a "game" that I am using to learn more about XNA. I need to figure out when these two objects intersect.

I noticed that the Texture2D objects has a property named "Bounds" which in turn has a method named "Intersects" which takes a Rectangle (the other Texture2D.Bounds) as an argument.

However when you run the code, the objects always intersect even if they are on separate sides of the screen. When I step into the code, I noticed that for the Texture2D Bounds I get 4 parameters back when you mouse over the Bounds and the X, and Y coordinates always read "X = 0, Y = 0" for both objects (hence they always intersect).

The thing that confuses me is the fact that the Bounds property is on the Texture rather than on the Position (or Vector2) of the objects. I eventually created a little helper method that takes in the objects and there positions and then calculate whether they intersect, but I'm sure there must be a better way.

any suggestions, pointers would be much appreciated.

Gineer

Answer 1

I found the XNA Creator Club tutorials based on another post to stackoverflow by Ben S. The Collision Series 1: 2D Rectangle Collision tutorial explains it all.

It seems you have to create new rectangles, based on the original rectangles moving around in the game every time you try to run the intersection method, which then will contain the updated X and Y coordinates.

I am still not quite sure why the original object rectangles position can not just be kept up to date, but if this is the way it should work, that's good enough for me... for now. ;-)

Answer 2

The Bounds property was added to the Texture2D class to simplify working with Viewports. More here.

You shouldn't think of the texture as being the object itself, it's merely what holds the data that gets drawn to the screen, whether it's used for a Sprite or RenderTarget. The position of objects or sprites and how position/moving is handled is entirely up to you, so you have to track and handle this yourself. That includes the position of any bounds.

The 2D Rectangle Collision tutorial is a good start, as you've already found :)