3D object selection

We are now able to select 3d objects by mouse clicks (2d object selection was already part of the ScummVM Wintermute port). Take a look at the following screenshot:

The cursor indicates that it is pointing onto our main protagonist.

Essentially what happens is that we have a bounding rectangle (constructed from a bounding box) for our model, which is added to a list. Every frame the list is traversed. If the mouse coordinates land in one of the rectangles, a more precise test is performed. In case of our model this means that we send a ray into the scene and check if it hits one of the triangles of the model. If so, the model becomes the active object, which means it can be selected by a mouse click.