Re: [Advent-devel] uses of advent

[Ingo Ruhnke]

"Frank W. Samuelson" <address@hidden> writes:

> Not to push, but when do you think you might work on this again?
> This code seems to be the best available adventure game engine for
> Linux out there, especially for the types of games I'd like to put
> together.

Hm, I can't really tell, at the moment am quite busy with Pingus. I
definitively will get back to this projects, but I don't really know
if it will be in a month or only in a year.

Even so Advent works basically, it has many many ugly quirks and not
very well designed pieces of code, its also pretty incomplete in a
number of regions. Once getting back at it I would probally start to
rewrite huge parts of the C++ part of the engine, since its not really
the best code and lots of the Scheme/C++ bindings could be generated
automatically by Swig. I would also like to move huge parts of the
code to the Scheme side and only keep basic drawing and input on the
C++ side. Another thing that really needs to be done is a split
between scenario descriptions and game code, so that one can easily
create a editor (or Gimp export scripts) for scenario definitions,
while not touching the game code.

> How difficult would it be to define a sort of generalized region
> trigger defined?

It should be relatively easy once familar with the code.

> For example, a door would be a specific kind of trigger region that
> changes scenarios.

Doors are at the moment a special kind of object, which triggers a
scenario change if the person reaches the doors hotspot.
Region-triggers shouldn't be necesarry for normal doors, only for
auto-opening StarTrek like ones.

> Could you give me a quick pointer to the location in the code to
> do this?  Thanks.

One would have to create a list of trigger objects in the Scenario
class which then get called on Scenario::update() and which can check
there if the current_person is at a given position and trigger a
scheme function if that is the case.

Trigger object might look like:

 class Trigger {
   privtae:
        SCM* callback_func;
   public:
        void update(Scenario* ) =0;
 }

 class RectTrigger : public Trigger {
   private:
     CL_Rect rect;
   public:
     void update(Scenario*) {
        if (rect.is_in(ScenarioLayer::current_person->get_pos()))
           gh_call1(callback_func, current_person.get_scm());
     }
 }

So after all trigger objects themself are not a problem to create, its
more the memory handling and the double-bookkeeping on both the Scheme
and the C++ site that will give a major headache here and there if one
works with the code.

I can implement the trigger-regions if you need them, but have you
actually tried to start using Advent or are you just looking around
for libraries/engines that might get the job done?

-- 
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