[DGD] the building blocks of grandiose worlds: geometry

Raymond Jennings shentino at gmail.com
Thu Mar 13 07:49:23 CET 2014 

Hey, jus tnoticed that the website for second contract is down.

Is everything ok?


On Wed, Sep 18, 2013 at 8:08 AM, Raymond Jennings <shentino at gmail.com>wrote:

> Likewise for kotaka.
>
> In particular you may find the Bigstruct subsystem useful for storing
> large amounts of data.  I tried to mimic C++'s STL containers in a way.
>
>
> On Wed, Sep 18, 2013 at 7:41 AM, James Smith <jgsmith at gmail.com> wrote:
>
>> Sorry for not replying sooner. Got busy with work and deadlines.
>>
>> I'm glad the resources might be useful.
>>
>> Feel free to incorporate any or all of the stuff I've done in the
>> second-contract lib into yours. I don't have as much time for development
>> as I'd like, so it's unlikely the lib will ever be as complete as it should
>> be for real use. It's something I'll tinker around with as time allows.
>>
>> -- Jim
>>
>>
>>
>> On Wed, Aug 28, 2013 at 12:06 AM, Raymond Jennings <shentino at gmail.com>wrote:
>>
>>> That blog you linked me to is a gold mine of information and maps to
>>> other treasures elsewhere.
>>>
>>> Definitely going to be reading it for awhile.
>>>
>>>
>>> On Tue, Aug 27, 2013 at 11:39 AM, James Smith <jgsmith at gmail.com> wrote:
>>>
>>>>  It's been a couple months since I was able to dive into code, but I've
>>>> been
>>>> trying to work out geometry based relationships rather than simple
>>>> environment containment.
>>>>
>>>> I have a few blog posts on the subject:
>>>>
>>>> http://www.second-contract.com/2013/02/scenes-and-settings/
>>>> http://www.second-contract.com/2013/03/scenes-and-settings-part-2/
>>>> http://www.second-contract.com/2013/03/proximity-and-movement/
>>>>
>>>> http://www.second-contract.com/2013/07/describing-scenes-paths-and-terrains/
>>>>
>>>> Some code is available on github:
>>>> https://github.com/jgsmith/second-contract
>>>>
>>>> If those might be helpful.
>>>>
>>>> -- Jim
>>>>
>>>>
>>>> On Tue, Aug 27, 2013 at 2:19 PM, Raymond Jennings <shentino at gmail.com
>>>> >wrote:
>>>>
>>>> > So the gist of veiling is that insider and outsider is inherently
>>>> > transitive, which is why it can be implied.
>>>> >
>>>> > If object A is outside object B, and B is outside C, then we already
>>>> know A
>>>> > is outside C and we don't even have to ask.
>>>> >
>>>> >
>>>> > On Tue, Aug 27, 2013 at 11:08 AM, Raymond Jennings <
>>>> shentino at gmail.com
>>>> > >wrote:
>>>> >
>>>> > > I should probably point out that in this process I'm trusting
>>>> geometry
>>>> > > queries to be honest.  Real geometry is consistent and allows for
>>>> this to
>>>> > > work.  This scheme will fail in a hurry if geometry handlers lie to
>>>> the
>>>> > > relation processing.
>>>> > >
>>>> > >
>>>> > > On Tue, Aug 27, 2013 at 11:07 AM, Raymond Jennings <
>>>> shentino at gmail.com
>>>> > >wrote:
>>>> > >
>>>> > >> I agree, it's vague ^^  I'm still trying to come up with the
>>>> terminology
>>>> > >> too.
>>>> > >>
>>>> > >> The basic idea is that I keep track of geometric (topologic?)
>>>> relations
>>>> > >> between neighboring objects.
>>>> > >>
>>>> > >> WRT one object that holds the relation mapping, another object can
>>>> be:
>>>> > >>
>>>> > >> 1.  An insider (completely contained by us)
>>>> > >> 2.  An intersecter (our boundaries criss cross)
>>>> > >> 3.  An outsider (completely containing us)
>>>> > >> 4.  An overlapper (our boundaries are perfectly congruent)
>>>> > >> 0.  No relation at all
>>>> > >>
>>>> > >> The default is 0, which as a nil is not even tracked, and any
>>>> object not
>>>> > >> in our relation map is assumed to be 0.
>>>> > >>
>>>> > >> Now the immediately useful part:
>>>> > >>
>>>> > >> First, direct neighbors:
>>>> > >>
>>>> > >> Objects in sets 1, 2, or 4 have parts of themselves inside us, and
>>>> > >> qualify for internal actions.
>>>> > >> Objects in sets 2, 3, or 4 have parts of themselves outside us, and
>>>> > >> qualify for external actions.
>>>> > >>
>>>> > >> Second, indirect neighbors:
>>>> > >>
>>>> > >> Additionally, objects in sets 2, 3, or 4 may have objects of their
>>>> own
>>>> > >> inside them, or in their own 1-, 2-, or 4- set.
>>>> > >>
>>>> > >> The 1's, 2's, and 4's of our 2's, 3's, and 4's are external
>>>> neighbors.
>>>> > >>
>>>> > >> The 2's, 3's, and 4's of our 1's, 2,s and 4's are our internal
>>>> > neighbors,
>>>> > >> and the rules of geometry (I think anyway) imply that those
>>>> indirect
>>>> > >> relations will also show up in our own 1's, 2's, or 4's
>>>> > >>
>>>> > >> By querying these lists, I can find neighbors.  This collection of
>>>> > >> neighbors is the list of candidates for things like visibility,
>>>> > >> interaction, targeting by nouns, and so on.
>>>> > >>
>>>> > >> That is the immediate usefulness.
>>>> > >>
>>>> > >> The second intended benefit:  Any outsider or insider acts as a
>>>> veil
>>>> > >> which hides everything behind it from processing, which in a
>>>> sizable
>>>> > world
>>>> > >> can obviously cut way down on the O(N^2) potentials, since anything
>>>> > >> affecting us from beyond that veil (no sirius black jokes please)
>>>> has
>>>> > to go
>>>> > >> through the veil to get to us, and since the outsider or insider is
>>>> > already
>>>> > >> keeping track of us in its own relation list, anything that cares
>>>> to
>>>> > find
>>>> > >> us can do so easily once it hits the veil and peeks behind it.
>>>> > >>
>>>> > >> This veiling effect also helps save on processing time when
>>>> geometry
>>>> > >> relations need to be checked for updating after an object moves.  I
>>>> > don't
>>>> > >> have to do a nasty O(N^2) check against everything else.  If I
>>>> change
>>>> > from
>>>> > >> a 1 to a 2 for object B, I only have to look at object B's 1's and
>>>> 2's
>>>> > and
>>>> > >> 4's to see who my new relations might be.  Similiarly, if I become
>>>> a 1
>>>> > of
>>>> > >> object B, I never have to look outside object B again to check
>>>> anything.
>>>> > >>
>>>> > >> This is all theoretical so far, but my prototype is working well
>>>> enough
>>>> > >> even now for the time being.
>>>> > >>
>>>> > >> As a quick and dirty example, let's say you have a few objects:
>>>> > >>
>>>> > >> object A is Fort Providence, and is a municipal zone.
>>>> > >> object B is the county of Kolechistan
>>>> > >> object C is Kolechistan's first police precinct
>>>> > >> object D is Kolechistan's fourth fire district
>>>> > >> object E is the state of Imporiton
>>>> > >> object F is the great and glorious nation of Triskellia
>>>> > >> object G is the state of Oregon.
>>>> > >>
>>>> > >> A is completely inside B, and also completely inside C and D
>>>> > >> B is completely inside E, and contains C and D
>>>> > >> C and D, being under different departments of Kolechistan, are
>>>> > >> intersecting each other, completely contain A, and are completely
>>>> > inside B
>>>> > >> E contains A
>>>> > >> F contains E
>>>> > >> F contains G
>>>> > >>
>>>> > >> Now, I have some optimizations already.
>>>> > >>
>>>> > >> Because E completely surrounds B, it doesn't even show up as a
>>>> relation
>>>> > >> at all for A, C, or D.  A, C, and D list B as their ousider, and
>>>> can
>>>> > safely
>>>> > >> ignore anything outside of B.  Which means that anything inside
>>>> > Kolechistan
>>>> > >> doesn't have to worry about the rest of Imporiton, or for that
>>>> matter,
>>>> > >> anything outside it such as F (Triskellia) and G (oregon).  Object
>>>> B
>>>> > acts
>>>> > >> as a veil that hides objects E, F, and G from objects B and C, and
>>>> > >> therefore from object A.
>>>> > >>
>>>> > >> Additinally, anything outside of Kolechistan doesn't need to worry
>>>> about
>>>> > >> anything inside of it.  Objects E, F, and G can completely ignore
>>>> object
>>>> > >> B's contents, since object E acts as a veil.
>>>> > >>
>>>> > >> Now if due to political events, the borders change, I can run a
>>>> geometry
>>>> > >> check on any objects.  If the check brings in new neighbors, I can
>>>> check
>>>> > >> against them as well, and if relations change I can then look for
>>>> more
>>>> > >> candidates.
>>>> > >>
>>>> > >> However, I only have to check my neighbors.  If after checking
>>>> them, no
>>>> > >> new candidates pop up, I can stop.  Anything that remains an
>>>> outsider
>>>> > >> cannot possibly have anything interesting outside itself, and
>>>> likewise
>>>> > for
>>>> > >> insiders.
>>>> > >>
>>>> > >> Now, if something happened outside that needed our attention, that
>>>> > >> something would first have to pierce the borders of our outsiders,
>>>> and
>>>> > if
>>>> > >> it did that, it would then check our outsider's relations
>>>> (including
>>>> > us).
>>>> > >>
>>>> > >> or, to put it back in the example, if a rocket was launched from
>>>> China
>>>> > >> and made its way to Fort Providence, you can bet your bones that
>>>> > >> Triskellia's air force radar would find out about it and the air
>>>> force
>>>> > >> would warn Imporiton's governor.  Imporiton's governor, in turn
>>>> would
>>>> > >> probably put the police precinct and fire district on high alert
>>>> by the
>>>> > >> time the rocket impacted.  Which is to say, that the rocket would
>>>> have
>>>> > to
>>>> > >> go through Triskellia's borders before Imporiton even saw it, and
>>>> > likewise
>>>> > >> through Imporiton's borders before the police and fire districts
>>>> saw it,
>>>> > >> and then likewise for Fort Providence itself.  Each penetration of
>>>> a
>>>> > veil
>>>> > >> brings up new objects to check for relations, and this process can
>>>> > recurse
>>>> > >> as needed until everything resolves.
>>>> > >>
>>>> > >> Since the police and fire zones intersect though, Fort Providence
>>>> still
>>>> > >> has to put up with jurisdictional squabbles.
>>>> > >>
>>>> > >> I hope this clarifies my idea better.
>>>> > >>
>>>> > >>
>>>> > >> On Mon, Aug 26, 2013 at 11:08 AM, Natasha Koroleva <
>>>> > >> natasha.i.koroleva at gmail.com> wrote:
>>>> > >>
>>>> > >>> Kind of vague description. I wonder there is a direction
>>>> attribute for
>>>> > >>> the relation (I assume this will be used for to handle exits)?
>>>> Overlap
>>>> > >>> includes some sort of index so that you know what is above and
>>>> below
>>>> > >>> the object?
>>>> > >>>
>>>> > >>> On Mon, Aug 26, 2013 at 10:51 AM, Raymond Jennings <
>>>> shentino at gmail.com
>>>> > >
>>>> > >>> wrote:
>>>> > >>> > Ok, so I just implemented very basic geometry processing, that
>>>> makes
>>>> > >>> sets
>>>> > >>> > of objects that are inside, outside, intersecting, overlapping,
>>>> or
>>>> > not
>>>> > >>> > related at all.
>>>> > >>> >
>>>> > >>> > This is the foundation for delegation and object hiding in my
>>>> > "colossal
>>>> > >>> > galaxy with detail down to the room" scheme.
>>>> > >>> >
>>>> > >>> > The gist is that for any two objects, object B can be inside
>>>> object
>>>> > A,
>>>> > >>> > outside it, intersecting it, or overlapping it (same position
>>>> and
>>>> > >>> shape)
>>>> > >>> >
>>>> > >>> > Ultimately, the relation list will seed the candidate list when
>>>> > >>> checking
>>>> > >>> > for neighbors.
>>>> > >>> >
>>>> > >>> > Can anyone see any flaws in this design?
>>>> > >>> > ____________________________________________
>>>> > >>> > https://mail.dworkin.nl/mailman/listinfo/dgd
>>>> > >>> ____________________________________________
>>>> > >>> https://mail.dworkin.nl/mailman/listinfo/dgd
>>>> > >>>
>>>> > >>
>>>> > >>
>>>> > >
>>>> > ____________________________________________
>>>> > https://mail.dworkin.nl/mailman/listinfo/dgd
>>>> >
>>>> ____________________________________________
>>>> https://mail.dworkin.nl/mailman/listinfo/dgd
>>>>
>>>
>>>
>>
>

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