require "extern"
--这个类找到了可视区域的9个点的坐标：左上、上的中点、右上、左的中点、左下、下的中点、右下、右的中点。一般用于使用相对坐标的场合，解决自适应屏幕的问题
--改写自VisibleRect.cpp
VisibleRect = class("VisibleRect")
VisibleRect.__index = VisibleRect

--CCRect VisibleRect::s_visibleRect; 
--创建一个CCRect实例：s_visibleRect（初始高、宽都是0）
VisibleRect.s_visibleRect = CCRect:new()
--[[
void VisibleRect::lazyInit() {
     if (s_visibleRect.size.width == 0.0f && s_visibleRect.size.height == 0.0f)     {
              CCEGLView* pEGLView = CCEGLView::sharedOpenGLView();         s_visibleRect.origin = pEGLView->getVisibleOrigin(); 
                s_visibleRect.size = pEGLView->getVisibleSize(); 
          }
 } 
]]
function VisibleRect:lazyInit()
    if (self.s_visibleRect.size.width == 0.0 and self.s_visibleRect.size.height == 0.0) then
        --sharedOpenGLView：get the shared main open gl window 
        local pEGLView = CCEGLView:sharedOpenGLView();
        self.s_visibleRect.origin = pEGLView:getVisibleOrigin();
        self.s_visibleRect.size = pEGLView:getVisibleSize();
    end
end

--返回一个CCRect，就是可视区域
function VisibleRect:getVisibleRect()
    self:lazyInit();
    -- return CCRectMake(s_visibleRect.origin.x, s_visibleRect.origin.y, s_visibleRect.size.width, s_visibleRect.size.height);
    return CCRectMake(self.s_visibleRect.origin.x, self.s_visibleRect.origin.y, self.s_visibleRect.size.width, self.s_visibleRect.size.height);
    --CCRectMake，输入坐标、长宽，输出一个CCRect
end

function VisibleRect:left()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x, self.s_visibleRect.origin.y+self.s_visibleRect.size.height/2);
end

function VisibleRect:right()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x+self.s_visibleRect.size.width, self.s_visibleRect.origin.y+self.s_visibleRect.size.height/2);
end

function VisibleRect:top()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x+self.s_visibleRect.size.width/2, self.s_visibleRect.origin.y+self.s_visibleRect.size.height);
end

function VisibleRect:bottom()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x+self.s_visibleRect.size.width/2, self.s_visibleRect.origin.y);
end

function VisibleRect:center()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x+self.s_visibleRect.size.width/2, self.s_visibleRect.origin.y+self.s_visibleRect.size.height/2);
end

function VisibleRect:leftTop()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x, self.s_visibleRect.origin.y+self.s_visibleRect.size.height);
end

function VisibleRect:rightTop()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x+self.s_visibleRect.size.width, self.s_visibleRect.origin.y+self.s_visibleRect.size.height);
end

function VisibleRect:leftBottom()
    self:lazyInit();
    return self.s_visibleRect.origin;
end

function VisibleRect:rightBottom()
    self:lazyInit();
    return ccp(self.s_visibleRect.origin.x+self.s_visibleRect.size.width, self.s_visibleRect.origin.y);
end