在Corona SDK中,当我绘制一条线时,如何使另一条线消失?

这是我到目前为止的代码:

local lines = {}
local lineGroup = display.newGroup()
local prevX,prevY
local isDrawing = false
local i = 0

local function distanceBetween(x1, y1, x2, y2)
    local dist_x = x2 - x1
    local dist_y = y2 - y1
    local distanceBetween = math.sqrt((dist_x*dist_x) + (dist_y*dist_y))
    return distanceBetween
end

local function drawLine(e)
    if(e.phase == "began") then
        prevX = e.x
        prevY = e.y
        isDrawing = true
        i = i + 1
    elseif(e.phase == "moved") then
        local distance = distanceBetween(prevX, prevY, e.x, e.y)
        if(isDrawing and distance < 100) then
            if(lines[i]) then lineGroup:remove(i) end
            lines[i] = display.newLine(prevX, prevY, e.x, e.y)
            lines[i]:setStrokeColor(1,45,1)
            lines[i].strokeWidth = 5
            local dist_x = e.x - prevX
            local dist_y = e.y - prevY
            physics.addBody(lines[i], "static", { density = 1, friction = 0.5, bounce = 2, shape = {0, 0, dist_x, dist_y, 0, 0} } )
            lineGroup:insert(lines[i])
        end
    elseif(e.phase == "ended") then
        isDrawing = false
    end
end

Runtime:addEventListener("touch",drawLine)

那么,我该如何让一条线在另一条线绘制时消失?

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用户1979583
用户1979583

如果你想在绘制新线条时隐藏所有其他线条,只需按照以下方式操作:

注释你的线条:

if(lines[i]) then lineGroup:remove(i) end

接着在 e.phase == "began" 中添加以下行:

lineGroup:removeSelf()
lineGroup = nil
lineGroup = display.newGroup()

继续愉快地编写代码…… :)

2014-08-24 04:56:16