cocos2dx 3.x designResolutionSize须主动设置

cocos2dx 3.x最初设置screenSize和designResolutionSize的地方如下：

bool AppDelegate::applicationDidFinishLaunching() {

// initialize director

auto director = Director::getInstance();

auto glview = director->getOpenGLView();

if(!glview) {

glview = GLViewImpl::create("title");

director->setOpenGLView(glview);

}

　　...

}

在iOS target下（在mac target下代码不一样），GLViewImpl::create(...)的实现代码如下：

GLViewImpl* GLViewImpl::create(const std::string& viewName)

{

auto ret = new (std::nothrow) GLViewImpl;

if(ret && ret->initWithFullScreen(viewName)) {

ret->autorelease();

return ret;

}

return nullptr;

}

bool GLViewImpl::initWithFullScreen(const std::string& viewName)

{

CGRect rect = [[UIScreen mainScreen] bounds];

Rect r;

r.origin.x = rect.origin.x;

r.origin.y = rect.origin.y;

r.size.width = rect.size.width;

r.size.height = rect.size.height;

return initWithRect(viewName, r, 1);

}

bool GLViewImpl::initWithRect(const std::string& viewName, Rect rect, float frameZoomFactor)

{

CGRect r = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);

convertAttrs();

CCEAGLView *eaglview = [CCEAGLView viewWithFrame: r

pixelFormat: (NSString*)_pixelFormat

depthFormat: _depthFormat

preserveBackbuffer: NO

sharegroup: nil

multiSampling: NO

numberOfSamples: 0];

[eaglview setMultipleTouchEnabled:YES];

_screenSize.width = _designResolutionSize.width = [eaglview getWidth];

_screenSize.height = _designResolutionSize.height = [eaglview getHeight];

//    _scaleX = _scaleY = [eaglview contentScaleFactor];

_eaglview = eaglview;

return true;

}

可见，默认cocos2dx 3.x会将designresolutionsize设成与screensize相等，于是显示效果如果在iphone上正常的话在ipad上肯定就不对了，所以我们必须主动设designresolutionsize。

例如，可以在创建完glview后设置designResolutionSize:

bool AppDelegate::applicationDidFinishLaunching() {

// initialize director

auto director = Director::getInstance();

auto glview = director->getOpenGLView();

if(!glview) {

glview = GLViewImpl::create("title");

director->setOpenGLView(glview);

}

//added by[yang chao]

//by default glview is created "fullscreen", namely screenSize = designResolutionSize.width = eaglview size

//but this is not what we want, we want use our own designResolutionSize, so we should set designResolution ourselves

{

director->getOpenGLView()->setDesignResolutionSize(1136,640,ResolutionPolicy::NO_BORDER);

}

　　

　...

}