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edit: is there any hook to se if a breakable entry thing has been damaged
edited 1×, last 26.06.11 03:42:45 pm
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CS2D
Scripts ai: nearest breakable
ai: nearest breakable
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edit: is there any hook to se if a breakable entry thing has been damaged
You get the size of the map, and iterate over every single tile and filter out tiles that do not fall within your square. The code looks something like this:
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local rect = {x, y, width, height}
xsize, ysize = (1+map("xsize")), (1+map("ysize"))
output = {}
for i = rect.x+rect.y*xsize, (rect.x + rect.width)+(rect.y + rect.height)*xsize -1 do
local x,y = i%ysize, math.floor(i/ysize)
if entity(x, y, "type") == 25 then table.insert(output, {x,y}) end
end
This is useful for cases where the entity : tile ratio is relatively high, IE the number of entities is almost equal to the total number of tiles in the selected region, in which case the lower bound time complexity of any algorithm must approach O(width*height).
However, in most cases, there are far fewer entities than tiles. (IE: de_cs2d has only 20 entities while there are 574 tiles, which means that only 3% of the tiles contain entities, and this is just a small map) In maps with large open spaces, it may no longer be feasible to check for breakable entities in a small confined rectangle while iterating over every tile will seem inefficient, especially if the map is anything larger than medium sized.
In cases where the spread of entities is sparse and the total count << tile count, then we can speed up the average lookup time by caching all of the entities at the start of the game.
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xsize, ysize = (1+map("xsize")), (1+map("ysize"))
cache = {}
for i = 0, xsize * ysize -1 do
local x,y = i%ysize, math.floor(i/ysize)
if entity(x,y,"type") == 25 then table.insert(cache, {x,y}) end
end
and then iterating through this list instead.
Also, if you have thousands of entities and want to do look up in only a specific rectangular region, there's a O(log n) data structure for such operations: http://en.wikipedia.org/wiki/Quadtree
Here's a functional implementation in ml: https://gist.github.com/1047975
break - if you are talking about damaging without breaking: nope, no hook for that. 1