首先！马上毕业了最近在找工作，还算有点时间好久没写东西了就写点东西吧！
进入主题，首先先思考算法和逻辑。把圆分为八块，每块45度。正上，正下，正左，正右会被X和Y 平分。一边一半各是22.5度。（PS：开始想用 斜率的，但是发现斜率是tan的图像，也就是无限趋近最大值和最小值的不好做判断最后就用了cos也可用sin）思考计算的过程图如下：
准备工作完了就开始，首先控制的人物有八个状态分别是：上，下，左，右，左上，左下，右上，右下的动画。不同的状态对应着不同的动画，触控点和圆心点作比较来判断是哪个方向的。判断算法如下图：
结构如下：
触控模块代码
box_tm:setTouchEnabled(true)
box_tm:setTouchSwallowEnabled(true)
box_tm:addTouchEventListener(function(event, x, y, prevX, prevY)
local x,y = x,y
if event == 'began' then
elseif event == "moved" then
cc,yy = box:getParent():convertToNodeSpace(ccp(x,y)) -- 变为世界坐标系
--box_tm:convertToWorldSpace(ccp(x,y))
box_tm:setPosition(cc,yy)
local up_x , up_y = box_tm:getPosition()
local loangle = self:CosAngle(up_x, up_y, box_x ,box_y)
if handle2 == nil then
handle2 = scheduler.scheduleGlobal(handler(self,self.TouchScheduler),0.1) -- 启动定时器
end
if up_y > box_tm_y then -- 判断在上边
--todo
if loangle >= 0 and loangle <= 22.5 then
--todo
dir_bar = "右"
elseif loangle > 22.5 and loangle <= 62.5 then
--todo
dir_bar = "右上"
elseif loangle >67.5 and loangle <= 112.5 then
dir_bar = "上"
elseif loangle >= 112.5 and loangle < 157.5 then
dir_bar = "左上"
else
dir_bar = "左"
end
else -- 判断在下面
--todo
if loangle >= 0 and loangle <= 22.5 then
--todo
dir_bar = "右"
elseif loangle > 22.5 and loangle <= 62.5 then
--todo
dir_bar = "右下"
elseif loangle >67.5 and loangle <= 112.5 then
dir_bar = "下"
elseif loangle >= 112.5 and loangle < 157.5 then
dir_bar = "左下"
else
--todo
dir_bar = "左"
end
end
elseif event == "ended" then
box_tm:setPosition(box_tm_x,box_tm_y)
self.critSprite:stopAllActions()
self.up_bar = 0
self.leftUp_bar =0
self.left_bar =0
self.rightUp_bar =0
self.right_bar =0
self.down_bar = 0
self.leftDown_bar = 0
self.rightDown_bar = 0
scheduler.unscheduleGlobal(handle2)
handle2 = nil
end
return true
end) 定时器中代码：
function Backpack:TouchScheduler()
run_x,run_y = self.critSprite:getPosition()
local speed = 3
if dir_bar == "上" then
if self.up_bar == 0 then
self:State("上")
self.up_bar = 1
self.rightUp_bar = 0
self.right_bar = 0
self.leftUp_bar = 0
self.left_bar = 0
self.down_bar = 0
self.leftDown_bar = 0
self.rightDown_bar = 0
end
self.critSprite:setPosition(run_x, run_y + speed)
elseif dir_bar == "下" then
if self.down_bar == 0 then
self:State("下")
self.down_bar = 1
self.rightUp_bar = 0
self.right_bar = 0
self.leftUp_bar = 0
self.left_bar = 0
self.up_bar = 0
self.leftDown_bar = 0
self.rightDown_bar = 0
end
self.critSprite:setPosition(run_x, run_y - speed)
………… -- 就这样的不多写了 最好把<span style="font-family: 'Comic Sans MS';">self:State("下") 中的 汉字改为英文（编码问题要小心）。我这就不改了，大家注意就是。</span> 状态：
function Backpack:State(...)
local dir = ...
if dir == "上" then
self:Action(0,8) -- 这里要注意参数是从第几个编号开始，往后多少张图
elseif dir == "下" then
self:Action(32,8)
elseif dir == "左" then
self:Action(48,8)
elseif dir == "右" then
self:Action(16,8)
elseif dir == "左上" then
self:Action(56,8)
elseif dir == "右上" then
self:Action(8,8)
elseif dir == "左下" then
self:Action(40,8)
elseif dir == "右下" then
self:Action(24,8)
end
end
function Backpack:Action(st,la)
self.critSprite:removeFromParentAndCleanup(true)
self.frames = display.newFrames("000%d.tga", st, la)
self.critSprite = display.newSprite(self.frames[1])
:addTo(display:getRunningScene(), SECOND_MENU_Z_ORDER)
self.critSprite:setScale(0.6)
animation = display.newAnimation(self.frames, 1 / 9)
transition.execute(self.critSprite,CCAnimate:create(animation),{
onComplete = function()
end})
self.critSprite:playAnimationForever(animation)
end
有什么问题大家可以交流共同学习共同进步。右下角会有我的QQ.
我尽力了，弄了很久 GIF 都发不出去，CSDN 说的是支持GIF 我也小于2M 了发出来还是不动得！ 求知道朋友告知一声怎么弄的，在这我先谢谢了！
先替代的发个百度网盘地址吧：http://pan.baidu.com/s/1pJzENqV
博主QQ: 294678265
很久没写博客了！今天来写个八方向摇杆基于quick cocos2d
原文：http://blog.csdn.net/lee_homi/article/details/45248815
