Helping my nephew with collision detection

[John Steinmetz]

One way is to have the ball look for a color ("color sees" or "color 
under"). When the ball sees the color of the wall, it can execute a 
command such as changing its heading. (A fun puzzle is to figure out 
how to change the heading so that the ball bounces off at a realistic 
angle.)

The advanced stages of the "drive a car" project use color sensing to 
keep the car on the road automatically.

	John


>Hi All,
>	I'm helping my nephew (13) get started writing a game in 
>Squeak (trying to move him more into the joy of writing games rather 
>than playing games) and he has made some great strides but has a 
>problem he can't get through. I'd like to help him but at this point 
>the extent of my wisdom is pointing him at Squeak. If any of you 
>could give us a hint about how to proceed we'd both greatly 
>appreciate it.
>
>	Starting from the "make a car" tutorial Byron has now made a 
>tank and a steering wheel  and some balls that he wants to bounce 
>back and forth between two walls. He's quite exceited about the cool 
>games he could create trying to drive the tank through a field where 
>these bullets are bouncing back and forth and he has discovered that 
>he needs collision detection But we haven't been able to implement 
>it yet. Currently he has his balls (bullets) bouncing backand forth 
>from the top and bottom of the Squeak world but we can't get them to 
>bounce off the walls he has made.
>
>	I've told him that I think Squeak has collision detection but 
>it is a little beyond me to actually show him how. It seems like we 
>want to write a test where the ball decides if it is touching a 
>wall. We see "touches" but we can't get it to allow us to say 
>touches the wall.
>
>
>	If any of you can help us we'd appreciate it. Thanks.
>
>Randy and Byron.


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