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opus/sys/apis/jumper/grid.lua
kepler155c@gmail.com fc243a9c12 Initial commit
2016-12-11 14:24:52 -05:00

430 lines
16 KiB
Lua

--- The Grid class.
-- Implementation of the `grid` class.
-- The `grid` is a implicit graph which represents the 2D
-- world map layout on which the `pathfinder` object will run.
-- During a search, the `pathfinder` object needs to save some critical values. These values are cached within each `node`
-- object, and the whole set of nodes are tight inside the `grid` object itself.
if (...) then
-- Dependencies
local _PATH = (...):gsub('%.grid$','')
-- Local references
local Utils = require (_PATH .. '.core.utils')
local Assert = require (_PATH .. '.core.assert')
local Node = require (_PATH .. '.core.node')
-- Local references
local pairs = pairs
local assert = assert
local next = next
local setmetatable = setmetatable
local floor = math.floor
local coroutine = coroutine
-- Offsets for straights moves
local straightOffsets = {
{x = 1, y = 0, z = 0} --[[W]], {x = -1, y = 0, z = 0}, --[[E]]
{x = 0, y = 1, z = 0} --[[S]], {x = 0, y = -1, z = 0}, --[[N]]
{x = 0, y = 0, z = 1} --[[U]], {x = 0, y = -0, z = -1}, --[[D]]
}
-- Offsets for diagonal moves
local diagonalOffsets = {
{x = -1, y = -1} --[[NW]], {x = 1, y = -1}, --[[NE]]
{x = -1, y = 1} --[[SW]], {x = 1, y = 1}, --[[SE]]
}
--- The `Grid` class.<br/>
-- This class is callable.
-- Therefore,_ <code>Grid(...)</code> _acts as a shortcut to_ <code>Grid:new(...)</code>.
-- @type Grid
local Grid = {}
Grid.__index = Grid
-- Specialized grids
local PreProcessGrid = setmetatable({},Grid)
local PostProcessGrid = setmetatable({},Grid)
PreProcessGrid.__index = PreProcessGrid
PostProcessGrid.__index = PostProcessGrid
PreProcessGrid.__call = function (self,x,y,z)
return self:getNodeAt(x,y,z)
end
PostProcessGrid.__call = function (self,x,y,z,create)
if create then return self:getNodeAt(x,y,z) end
return self._nodes[y] and self._nodes[y][x] and self._nodes[y][x][z]
end
--- Inits a new `grid`
-- @class function
-- @tparam table|string map A collision map - (2D array) with consecutive indices (starting at 0 or 1)
-- or a `string` with line-break chars (<code>\n</code> or <code>\r</code>) as row delimiters.
-- @tparam[opt] bool cacheNodeAtRuntime When __true__, returns an empty `grid` instance, so that
-- later on, indexing a non-cached `node` will cause it to be created and cache within the `grid` on purpose (i.e, when needed).
-- This is a __memory-safe__ option, in case your dealing with some tight memory constraints.
-- Defaults to __false__ when omitted.
-- @treturn grid a new `grid` instance
-- @usage
-- -- A simple 3x3 grid
-- local myGrid = Grid:new({{0,0,0},{0,0,0},{0,0,0}})
--
-- -- A memory-safe 3x3 grid
-- myGrid = Grid('000\n000\n000', true)
function Grid:new(map, cacheNodeAtRuntime)
if type(map) == 'string' then
assert(Assert.isStrMap(map), 'Wrong argument #1. Not a valid string map')
map = Utils.strToMap(map)
end
--assert(Assert.isMap(map),('Bad argument #1. Not a valid map'))
assert(Assert.isBool(cacheNodeAtRuntime) or Assert.isNil(cacheNodeAtRuntime),
('Bad argument #2. Expected \'boolean\', got %s.'):format(type(cacheNodeAtRuntime)))
if cacheNodeAtRuntime then
return PostProcessGrid:new(map,walkable)
end
return PreProcessGrid:new(map,walkable)
end
--- Checks if `node` at [x,y] is __walkable__.
-- Will check if `node` at location [x,y] both *exists* on the collision map and *is walkable*
-- @class function
-- @tparam int x the x-location of the node
-- @tparam int y the y-location of the node
-- @tparam[opt] string|int|func walkable the value for walkable locations in the collision map array (see @{Grid:new}).
-- Defaults to __false__ when omitted.
-- If this parameter is a function, it should be prototyped as __f(value)__ and return a `boolean`:
-- __true__ when value matches a __walkable__ `node`, __false__ otherwise. If this parameter is not given
-- while location [x,y] __is valid__, this actual function returns __true__.
-- @tparam[optchain] int clearance the amount of clearance needed. Defaults to 1 (normal clearance) when not given.
-- @treturn bool __true__ if `node` exists and is __walkable__, __false__ otherwise
-- @usage
-- -- Always true
-- print(myGrid:isWalkableAt(2,3))
--
-- -- True if node at [2,3] collision map value is 0
-- print(myGrid:isWalkableAt(2,3,0))
--
-- -- True if node at [2,3] collision map value is 0 and has a clearance higher or equal to 2
-- print(myGrid:isWalkableAt(2,3,0,2))
--
function Grid:isWalkableAt(x, y, z, walkable, clearance)
local nodeValue = self._map[y] and self._map[y][x] and self._map[y][x][z]
if nodeValue then
if not walkable then return true end
else
return false
end
local hasEnoughClearance = not clearance and true or false
if not hasEnoughClearance then
if not self._isAnnotated[walkable] then return false end
local node = self:getNodeAt(x,y,z)
local nodeClearance = node:getClearance(walkable)
hasEnoughClearance = (nodeClearance >= clearance)
end
if self._eval then
return walkable(nodeValue) and hasEnoughClearance
end
return ((nodeValue == walkable) and hasEnoughClearance)
end
--- Returns the `grid` width.
-- @class function
-- @treturn int the `grid` width
-- @usage print(myGrid:getWidth())
function Grid:getWidth()
return self._width
end
--- Returns the `grid` height.
-- @class function
-- @treturn int the `grid` height
-- @usage print(myGrid:getHeight())
function Grid:getHeight()
return self._height
end
--- Returns the collision map.
-- @class function
-- @treturn map the collision map (see @{Grid:new})
-- @usage local map = myGrid:getMap()
function Grid:getMap()
return self._map
end
--- Returns the set of nodes.
-- @class function
-- @treturn {{node,...},...} an array of nodes
-- @usage local nodes = myGrid:getNodes()
function Grid:getNodes()
return self._nodes
end
--- Returns the `grid` bounds. Returned values corresponds to the upper-left
-- and lower-right coordinates (in tile units) of the actual `grid` instance.
-- @class function
-- @treturn int the upper-left corner x-coordinate
-- @treturn int the upper-left corner y-coordinate
-- @treturn int the lower-right corner x-coordinate
-- @treturn int the lower-right corner y-coordinate
-- @usage local left_x, left_y, right_x, right_y = myGrid:getBounds()
function Grid:getBounds()
return self._min_x, self._min_y, self._min_z, self._max_x, self._max_y, self._max_z
end
--- Returns neighbours. The returned value is an array of __walkable__ nodes neighbouring a given `node`.
-- @class function
-- @tparam node node a given `node`
-- @tparam[opt] string|int|func walkable the value for walkable locations in the collision map array (see @{Grid:new}).
-- Defaults to __false__ when omitted.
-- @tparam[optchain] bool allowDiagonal when __true__, allows adjacent nodes are included (8-neighbours).
-- Defaults to __false__ when omitted.
-- @tparam[optchain] bool tunnel When __true__, allows the `pathfinder` to tunnel through walls when heading diagonally.
-- @tparam[optchain] int clearance When given, will prune for the neighbours set all nodes having a clearance value lower than the passed-in value
-- Defaults to __false__ when omitted.
-- @treturn {node,...} an array of nodes neighbouring a given node
-- @usage
-- local aNode = myGrid:getNodeAt(5,6)
-- local neighbours = myGrid:getNeighbours(aNode, 0, true)
function Grid:getNeighbours(node, walkable, allowDiagonal, tunnel, clearance)
local neighbours = {}
for i = 1,#straightOffsets do
local n = self:getNodeAt(
node._x + straightOffsets[i].x,
node._y + straightOffsets[i].y,
node._z + straightOffsets[i].z
)
if n and self:isWalkableAt(n._x, n._y, n._z, walkable, clearance) then
neighbours[#neighbours+1] = n
end
end
if not allowDiagonal then return neighbours end
tunnel = not not tunnel
for i = 1,#diagonalOffsets do
local n = self:getNodeAt(
node._x + diagonalOffsets[i].x,
node._y + diagonalOffsets[i].y
)
if n and self:isWalkableAt(n._x, n._y, walkable, clearance) then
if tunnel then
neighbours[#neighbours+1] = n
else
local skipThisNode = false
local n1 = self:getNodeAt(node._x+diagonalOffsets[i].x, node._y)
local n2 = self:getNodeAt(node._x, node._y+diagonalOffsets[i].y)
if ((n1 and n2) and not self:isWalkableAt(n1._x, n1._y, walkable, clearance) and not self:isWalkableAt(n2._x, n2._y, walkable, clearance)) then
skipThisNode = true
end
if not skipThisNode then neighbours[#neighbours+1] = n end
end
end
end
return neighbours
end
--- Grid iterator. Iterates on every single node
-- in the `grid`. Passing __lx, ly, ex, ey__ arguments will iterate
-- only on nodes inside the bounding-rectangle delimited by those given coordinates.
-- @class function
-- @tparam[opt] int lx the leftmost x-coordinate of the rectangle. Default to the `grid` leftmost x-coordinate (see @{Grid:getBounds}).
-- @tparam[optchain] int ly the topmost y-coordinate of the rectangle. Default to the `grid` topmost y-coordinate (see @{Grid:getBounds}).
-- @tparam[optchain] int ex the rightmost x-coordinate of the rectangle. Default to the `grid` rightmost x-coordinate (see @{Grid:getBounds}).
-- @tparam[optchain] int ey the bottom-most y-coordinate of the rectangle. Default to the `grid` bottom-most y-coordinate (see @{Grid:getBounds}).
-- @treturn node a `node` on the collision map, upon each iteration step
-- @treturn int the iteration count
-- @usage
-- for node, count in myGrid:iter() do
-- print(node:getX(), node:getY(), count)
-- end
function Grid:iter(lx,ly,lz,ex,ey,ez)
local min_x = lx or self._min_x
local min_y = ly or self._min_y
local min_z = lz or self._min_z
local max_x = ex or self._max_x
local max_y = ey or self._max_y
local max_z = ez or self._max_z
local x, y, z
z = min_z
return function()
x = not x and min_x or x+1
if x > max_x then
x = min_x
y = y+1
end
y = not y and min_y or y+1
if y > max_y then
y = min_y
z = z+1
end
if z > max_z then
z = nil
end
return self._nodes[y] and self._nodes[y][x] and self._nodes[y][x][z] or self:getNodeAt(x,y,z)
end
end
--- Grid iterator. Iterates on each node along the outline (border) of a squared area
-- centered on the given node.
-- @tparam node node a given `node`
-- @tparam[opt] int radius the area radius (half-length). Defaults to __1__ when not given.
-- @treturn node a `node` at each iteration step
-- @usage
-- for node in myGrid:around(node, 2) do
-- ...
-- end
function Grid:around(node, radius)
local x, y, z = node._x, node._y, node._z
radius = radius or 1
local _around = Utils.around()
local _nodes = {}
repeat
local state, x, y, z = coroutine.resume(_around,x,y,z,radius)
local nodeAt = state and self:getNodeAt(x, y, z)
if nodeAt then _nodes[#_nodes+1] = nodeAt end
until (not state)
local _i = 0
return function()
_i = _i+1
return _nodes[_i]
end
end
--- Each transformation. Calls the given function on each `node` in the `grid`,
-- passing the `node` as the first argument to function __f__.
-- @class function
-- @tparam func f a function prototyped as __f(node,...)__
-- @tparam[opt] vararg ... args to be passed to function __f__
-- @treturn grid self (the calling `grid` itself, can be chained)
-- @usage
-- local function printNode(node)
-- print(node:getX(), node:getY())
-- end
-- myGrid:each(printNode)
function Grid:each(f,...)
for node in self:iter() do f(node,...) end
return self
end
--- Each (in range) transformation. Calls a function on each `node` in the range of a rectangle of cells,
-- passing the `node` as the first argument to function __f__.
-- @class function
-- @tparam int lx the leftmost x-coordinate coordinate of the rectangle
-- @tparam int ly the topmost y-coordinate of the rectangle
-- @tparam int ex the rightmost x-coordinate of the rectangle
-- @tparam int ey the bottom-most y-coordinate of the rectangle
-- @tparam func f a function prototyped as __f(node,...)__
-- @tparam[opt] vararg ... args to be passed to function __f__
-- @treturn grid self (the calling `grid` itself, can be chained)
-- @usage
-- local function printNode(node)
-- print(node:getX(), node:getY())
-- end
-- myGrid:eachRange(1,1,8,8,printNode)
function Grid:eachRange(lx,ly,ex,ey,f,...)
for node in self:iter(lx,ly,ex,ey) do f(node,...) end
return self
end
--- Map transformation.
-- Calls function __f(node,...)__ on each `node` in a given range, passing the `node` as the first arg to function __f__ and replaces
-- it with the returned value. Therefore, the function should return a `node`.
-- @class function
-- @tparam func f a function prototyped as __f(node,...)__
-- @tparam[opt] vararg ... args to be passed to function __f__
-- @treturn grid self (the calling `grid` itself, can be chained)
-- @usage
-- local function nothing(node)
-- return node
-- end
-- myGrid:imap(nothing)
function Grid:imap(f,...)
for node in self:iter() do
node = f(node,...)
end
return self
end
--- Map in range transformation.
-- Calls function __f(node,...)__ on each `node` in a rectangle range, passing the `node` as the first argument to the function and replaces
-- it with the returned value. Therefore, the function should return a `node`.
-- @class function
-- @tparam int lx the leftmost x-coordinate coordinate of the rectangle
-- @tparam int ly the topmost y-coordinate of the rectangle
-- @tparam int ex the rightmost x-coordinate of the rectangle
-- @tparam int ey the bottom-most y-coordinate of the rectangle
-- @tparam func f a function prototyped as __f(node,...)__
-- @tparam[opt] vararg ... args to be passed to function __f__
-- @treturn grid self (the calling `grid` itself, can be chained)
-- @usage
-- local function nothing(node)
-- return node
-- end
-- myGrid:imap(1,1,6,6,nothing)
function Grid:imapRange(lx,ly,ex,ey,f,...)
for node in self:iter(lx,ly,ex,ey) do
node = f(node,...)
end
return self
end
-- Specialized grids
-- Inits a preprocessed grid
function PreProcessGrid:new(map)
local newGrid = {}
newGrid._map = map
newGrid._nodes, newGrid._min_x, newGrid._max_x, newGrid._min_y, newGrid._max_y, newGrid._min_z, newGrid._max_z = Utils.arrayToNodes(newGrid._map)
newGrid._width = (newGrid._max_x-newGrid._min_x)+1
newGrid._height = (newGrid._max_y-newGrid._min_y)+1
newGrid._length = (newGrid._max_z-newGrid._min_z)+1
newGrid._isAnnotated = {}
return setmetatable(newGrid,PreProcessGrid)
end
-- Inits a postprocessed grid
function PostProcessGrid:new(map)
local newGrid = {}
newGrid._map = map
newGrid._nodes = {}
newGrid._min_x, newGrid._max_x, newGrid._min_y, newGrid._max_y = Utils.getArrayBounds(newGrid._map)
newGrid._width = (newGrid._max_x-newGrid._min_x)+1
newGrid._height = (newGrid._max_y-newGrid._min_y)+1
newGrid._isAnnotated = {}
return setmetatable(newGrid,PostProcessGrid)
end
--- Returns the `node` at location [x,y].
-- @class function
-- @name Grid:getNodeAt
-- @tparam int x the x-coordinate coordinate
-- @tparam int y the y-coordinate coordinate
-- @treturn node a `node`
-- @usage local aNode = myGrid:getNodeAt(2,2)
-- Gets the node at location <x,y> on a preprocessed grid
function PreProcessGrid:getNodeAt(x,y,z)
return self._nodes[y] and self._nodes[y][x] and self._nodes[y][x][z] or nil
end
-- Gets the node at location <x,y> on a postprocessed grid
function PostProcessGrid:getNodeAt(x,y,z)
if not x or not y or not z then return end
if Utils.outOfRange(x,self._min_x,self._max_x) then return end
if Utils.outOfRange(y,self._min_y,self._max_y) then return end
if Utils.outOfRange(z,self._min_z,self._max_z) then return end
if not self._nodes[y] then self._nodes[y] = {} end
if not self._nodes[y][x] then self._nodes[y][x] = {} end
if not self._nodes[y][x][z] then self._nodes[y][x][z] = Node:new(x,y,z) end
return self._nodes[y][x][z]
end
return setmetatable(Grid,{
__call = function(self,...)
return self:new(...)
end
})
end