62 lines
1.3 KiB
Lua
62 lines
1.3 KiB
Lua
--Shitty acceleration structure: get closest point in set.
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--Assumed to be in world coordinates: ( -180, 180 ) x ( -100, 100 )
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local t = {}
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local hashes = {}
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local math = math
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local hash = function( x, y, debug )
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local s = "h"..("%2d%2d"):format(math.floor( 0.5 + (180 + x) / 10 ), math.floor( 0.5 + (100 + y) / 10 ) )
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return s
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end
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function t.getClosestPoint( points, x, y )
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local closePoints = hashes[hash( x, y )]
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if not closePoints then return end
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local distance = math.huge
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local px, py, point
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for k, v in pairs(closePoints) do
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px, py = v.x, v.y
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local d = (x - px) * (x - px) + (y - py) * (y - py)
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if d < distance then
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distance = d
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point = v
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end
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end
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return point
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end
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function t.Edit( points, point, x, y )
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local h = hashes[hash( point.x, point.y )]
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if h then
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for i, p in pairs(h) do
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if p == point then
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table.remove( h, i )
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break
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end
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end
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end
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table.insert( hashes[ hash( x, y ) ], point )
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point.x = x
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point.y = y
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end
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function t.Add( points, x, y )
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end
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function t.New( points )
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for i = 1, #points do
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local x, y = points[i].x, points[i].y
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local h = hash( x, y )
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hashes[h] = hashes[h] or {}
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hashes[h][#hashes[h] + 1] = points[i]
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end
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return setmetatable( points, {__index = t } )
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end
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return t |