突出显示网格中的路径

Question

在我的基于网格的游戏中，玩家点击一个单位然后移动他的手指以确定该单位应该移动的位置。我使用"Jumper" library进行寻路。获取路径的代码完美无缺，但突出显示路径的代码并非如此。

local function onTileTouch( event )
    local phase = event.phase
    local tile = event.target


    if ( phase == "began"  ) then
        -- I could create the line here
    elseif ( phase == "moved" ) then
        createPath( tile )

        -- Getting the position of the first tile based on where the unit is
        local t = tiles[currentSelectedUnit.pos.y][currentSelectedUnit.pos.x]

        -- Create the line at the first tile's position
        line = display.newLine( t.x, t.y, t.x, t.y )
        line:setStrokeColor( 1,0,0 )
        line.strokeWidth = 8

        -- "foundPath" is a table of tiles of the correct path
        for i=1,#foundPath do
            line:append( foundPath[i].x,foundPath[i].y )
        end
    elseif ( phase == "ended" or phase == "cancelled" ) then
end

在＆＃34;移动＆＃34;中创建的线条看起来并不正确。相。然而，当它在＆＃34;开始＆＃34;中创建时看起来非常准确。阶段，然后在＆＃34;移动＆＃34;相。但是在这种情况下，会绘制另一条额外的线，它不会跟随路径，而是直接从起始区块到结束区块。 我的第二个问题是＆＃34;开始＆＃34;阶段方法，我不知道如何继续删除旧行并为新的正确路径创建一个新行。

如果需要任何额外信息，请告诉我。

Answer 1

我不确定你到底想要什么，所以我准备了自己的版本：

test.lua

local composer   = require( 'composer' )
-- Library setup
local Grid       = require ( 'jumper.grid' ) -- The grid class
local Pathfinder = require ( 'jumper.pathfinder' ) -- The pathfinder lass

local scene = composer.newScene()

-- First, set a collision map and value for walkable tiles
local board  = { 
    tiles = {}, 
    walkable = 0, 
    map = {
        {0,1,0,0,0},
        {0,1,0,1,0},
        {0,1,0,0,0},
        {0,0,0,0,0},
    } 
}

local function createPath( startx, starty, endx, endy )

    -- Creates a grid object
    local grid = Grid( board.map ) 
    -- Creates a pathfinder object using Jump Point Search
    local myFinder = Pathfinder( grid, 'JPS', board.walkable ) 
    -- Calculates the path, and its length
    local path = myFinder:getPath( startx, starty, endx, endy )

    return path

end

function scene:create( event )

    local sceneGroup = self.view
    local rowNum = #board.map
    local colNum = #board.map[1]
    local width  = 40
    local height = width
    local margin = 5

    local function touch( self, event )

        local phase = event.phase
        local endTile = event.target

        if ( phase == 'began'  ) then

            board.startTile = endTile

        elseif ( phase == 'moved' ) then

            if board.startTile ~= endTile then

                if ( board.endTile ~= endTile ) then

                    board.endTile = endTile

                    local path = createPath( board.startTile.col, board.startTile.row, board.endTile.col, board.endTile.row )

                    if path then

                        -- Remove old lines
                        display.remove( board.lines )
                        board.lines = nil           

                        -- Create new line
                        board.lines = display.newLine( sceneGroup, board.startTile.x, board.startTile.y, board.startTile.x, board.startTile.y + 1 )

                        for node, count in path:nodes() do

                            local id = colNum * ( node:getY() - 1 ) + node:getX()
                            local tile = board.tiles[id]
                            board.lines:append( tile.x, tile.y )    

                        end 

                    end 

                end 

            else

                -- Remove old lines
                display.remove( board.lines )
                board.lines = nil
                board.endTile = nil

            end 

        elseif ( phase == 'ended' or phase == 'cancelled' ) then

            -- Remove old lines
            display.remove( board.lines )
            board.lines = nil
            board.endTile = nil
            board.startTile = nil

        end 

    end 

    for i=1, rowNum do

        for j=1, colNum do

            local tile = display.newRect( sceneGroup, (width + margin ) * j, ( height + margin ) * i, width, height ) 
            tile.col = j 
            tile.row = i 
            tile.touch = touch
            -- Add listener and change color for walkable tile
            if board.map[i][j] == board.walkable then

                tile:addEventListener( 'touch' )
                tile:setFillColor( 0, 0.5, 0.5 )

            end 

            local id = colNum * ( i -1 ) + j
            board.tiles[id] = tile

        end

    end     

end

function scene:show( event )
    local sceneGroup = self.view
    local phase = event.phase
    if phase == 'will' then

    elseif phase == 'did' then

    end
end

function scene:hide( event )
    local sceneGroup = self.view
    local phase = event.phase
    if event.phase == 'will' then

    elseif phase == 'did' then

    end
end

function scene:destroy( event )
local sceneGroup = self.view


end

scene:addEventListener( 'create', scene )
scene:addEventListener( 'show', scene )
scene:addEventListener( 'hide', scene )
scene:addEventListener( 'destroy', scene )

return scene