[plt-scheme] Re: Writing a game and have questions

In the specific case of PLT Scheme's GUI toolkit, probably the easiest
thing to do is to both draw and determine if points are in regions via
region% object or dc-path% objects.

Robby

On Sat, Sep 20, 2008 at 2:35 PM, Neil Van Dyke <neil at neilvandyke.org> wrote:
> I don't know the answer to the offscreen buffer question.
>
> If you decide not to go that route, and these objects like monsters are not
> all bound to particular hex tiles or do not fill the tiles completely for
> purposes of picking (so you can't just find the hex tile and then check a
> data structure to see whether there's a monster associated with the hex
> tile), you might consider implementing this kind of object picking as a
> two-step algorithm.  The first step would be to determine which if any of
> the monster-like objects is clicked  (by, e.g., scanning linearly through
> lists of them and checking for point inside polygons, or by using a fancy
> computational geometry method).  The second step would be, if no
> monster-like thing was clicked, to use the simple arithmetic means of
> determining which hex tile was clicked.  I think that would be more of the
> CAD way of doing things, and it is not subject to some of the limitations
> and potential headaches of the off-screen pixel-peeping method.
>
> Probably for your game, either approach would be fine, but just thought I'd
> mention it, in case you have trouble with pixel-peeping or you later need to
> implement something that scale better.  (You did ask originally for other
> approach suggestions. :)
>
> Deep wrote at 09/20/2008 01:54 PM:
>>
>> The reason for the offscreen buffer scheme was that its a bit more
>> general. In the sense that if tomm I was using some ill defined shapes
>> (like say a Monster which would be an image with alpha) I could still
>> render their outlines to the offscreen click map and get the results.
>>
>
>
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