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2019-06-10 10:31 Arno  
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with open borders - not possible! :-o

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2019-06-10 12:39 shredder  
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no matter what, the right boulder falls first :O

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2019-06-10 13:31 Arno  
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yes, and the only difference with previous cave is the open border setting.  
perhaps the cave scan works different when open borders are enabled. it seems that rockford's move is updated on the map before start of the cave scan...  krissz  or  nesdori , can you explain?

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2019-06-10 14:27 Piter  
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interesting ;-)

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2019-06-10 14:30 nesdori  
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i really can't explain this behaviour. open border boulder dash engine isn't standardized and it varies from implementation to implementation. normal bd caves are scanned from left to right but the problem with open borders is that there isn't left and right border anymore. if you still always start scan from the point where left border was when cave started there will be a discontinuity point at the edge of start and end point of scanning. there will be all kind of strange effects when objects cross the discontinuity point or when objects are falling along the edge. when  krissz  did his first open border implementation it had all kind of bugs (like sometimes rockford would die if boulder falled through the bottom line and rockford was located at certain position on the top). then  krissz  said that he thought throughly about open border problems and made a lot of fixes. this behaviour that right boulder isn't falling first anymore is probably effect of those fixes. it appears that the fixes affect not just the seam area around the discontinuity point but the whole cave.  
  
i haven't thought deeply about open border problems but i think there really isn't one correct way to do it. if you fix some things there will be some other problems on other caves. one may think that it's trivial to remove borders from bd caves but it really isn't. original scanning method was not designed to handle open borders.  
  
one interesting idea i have thought about it is using a dynamic scanning so that the start point of scanning is continuously changing and is related to the location of rockford so that the rockford is always at the center of scanning area. that way rockford would never reach the discontinuity point and there won't be rockford-related open border effects. there would of course still be some problems away from rockford and objects at the edge would behave differently depending on where rockford is. that would allow very nasty engine tricks and you would need another camera to see them because the discontinuity point would be far from rockford :)

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2019-06-10 14:58 Arno  
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very interesting thoughts  nesdori !  
  
some time ago i also thought about the open border problems. i had the following idea:   
instead of one cave scan per frame, do multiple cave scans: one for each point on the map as starting point (or a sample, like all points on the diagonal). this gives a set of maps which may differ at various points. then, create the final map of the frame by taking for every position the item that occurs on most of the maps from the sample.  
  
idea is that items in the middle will behave normally, while items near the border may behave exceptionally. Given that within the sample of maps, a position mostly occurs in the middle, the final map will show the normal behaviour.  
  
i'm not sure if such method has other problems, like items duplicating themselves or disappearing.  
for very small caves, possibly the "most occurring" item cannot be determined when there are multiple most ocurring items.  
finally, calculation times may be an issue (in bigger caves).

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2019-06-10 15:33 nesdori  
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 Arno , your multiple scan samples is an interesting idea. performance won't be an issue. scanning was designed to be very simple and fast because it had to run smoothly on 8-bit machines. modern machines can do thousands of scans / frame, even  krissz 's javascript :)

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2019-06-11 19:00 Arno  
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thx  nesdori ! :-)  
  
 krissz , when you return from holiday, i'd like to know your view on the topics discussed below.  
not that i suggest any change; this bd remake is great as it is now! i'm just curious about your opinion as a bd developer. :-)

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2019-06-24 19:29 Arno  
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i modified the cave to make it possible :-)  
  
 krissz , hope you have the possibility to share your view somehow; i'm curious! :-)

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2019-06-25 20:49 trischi83  
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you did not need both diamonds..................................  
  
can not see the forest for the trees ! ! ! ! ! ! ! ! ! ! ! ! ! !   
  
i will get my pension like  enrico ...............................  
  
because i am to old for this side ( game ) ! ! ! ! ! ! ! ! ! ! !   
  
and then i am able to enjoy my pension..........................  
  
:- ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) )   
  
to much younger players are here................................  
  
has just registered on  krissz  his side..........................  
  
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generation change...............................................  
  
i think so......................................................  
  
;- ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) )   
  
but their way...................................................  
  
is extreme long......or short...................................  
  
:- ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) )   
  
but no one here has played this cave at the age from 2 years....  
  
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:-OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO  
  
only one person.................................................  
  
at the age of 2 years...........................................  
  
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he know it and he know who i mean...............................  
  
and  nesdori  also has to get his pension! ! ! ! ! ! ! ! ! ! ! ! !   
  
the ooooold man.................................................  
  
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