mirror of https://github.com/kepler155c/opus
102 lines
2.8 KiB
Lua
102 lines
2.8 KiB
Lua
--- The Grid class.
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-- Implementation of the `grid` class.
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-- The `grid` is a implicit graph which represents the 2D
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-- world map layout on which the `pathfinder` object will run.
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-- During a search, the `pathfinder` object needs to save some critical values.
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-- These values are cached within each `node`
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-- object, and the whole set of nodes are tight inside the `grid` object itself.
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if (...) then
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-- Dependencies
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local _PATH = (...):gsub('%.grid$','')
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-- Local references
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local Utils = require (_PATH .. '.core.utils')
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local Node = require (_PATH .. '.core.node')
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-- Local references
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local setmetatable = setmetatable
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-- Offsets for straights moves
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local straightOffsets = {
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{x = 1, y = 0, z = 0} --[[W]], {x = -1, y = 0, z = 0}, --[[E]]
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{x = 0, y = 1, z = 0} --[[S]], {x = 0, y = -1, z = 0}, --[[N]]
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{x = 0, y = 0, z = 1} --[[U]], {x = 0, y = -0, z = -1}, --[[D]]
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}
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local Grid = {}
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Grid.__index = Grid
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function Grid:new(dim)
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local newGrid = { }
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newGrid._min_x, newGrid._max_x = dim.x, dim.ex
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newGrid._min_y, newGrid._max_y = dim.y, dim.ey
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newGrid._min_z, newGrid._max_z = dim.z, dim.ez
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newGrid._nodes = { }
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newGrid._width = (newGrid._max_x-newGrid._min_x)+1
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newGrid._height = (newGrid._max_y-newGrid._min_y)+1
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newGrid._length = (newGrid._max_z-newGrid._min_z)+1
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return setmetatable(newGrid,Grid)
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end
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function Grid:isWalkableAt(x, y, z)
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local node = self:getNodeAt(x,y,z)
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return node and node.walkable ~= 1
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end
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function Grid:getWidth()
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return self._width
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end
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function Grid:getHeight()
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return self._height
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end
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function Grid:getNodes()
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return self._nodes
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end
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function Grid:getBounds()
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return self._min_x, self._min_y, self._min_z, self._max_x, self._max_y, self._max_z
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end
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--- Returns neighbours. The returned value is an array of __walkable__ nodes neighbouring a given `node`.
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-- @treturn {node,...} an array of nodes neighbouring a given node
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function Grid:getNeighbours(node)
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local neighbours = {}
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for i = 1,#straightOffsets do
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local n = self:getNodeAt(
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node.x + straightOffsets[i].x,
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node.y + straightOffsets[i].y,
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node.z + straightOffsets[i].z
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)
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if n and self:isWalkableAt(n.x, n.y, n.z) then
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neighbours[#neighbours+1] = n
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end
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end
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return neighbours
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end
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function Grid:getNodeAt(x,y,z)
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if not x or not y or not z then return end
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if Utils.outOfRange(x,self._min_x,self._max_x) then return end
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if Utils.outOfRange(y,self._min_y,self._max_y) then return end
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if Utils.outOfRange(z,self._min_z,self._max_z) then return end
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-- inefficient
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if not self._nodes[y] then self._nodes[y] = {} end
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if not self._nodes[y][x] then self._nodes[y][x] = {} end
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if not self._nodes[y][x][z] then self._nodes[y][x][z] = Node:new(x,y,z) end
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return self._nodes[y][x][z]
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end
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return setmetatable(Grid,{
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__call = function(self,...)
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return self:new(...)
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end
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})
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end
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