cocos2dx进阶学习之屏幕适配

http://blog.csdn.net/itcastcpp/article/details/18608437 背景 在学习cocos2dx时，我们在main函数中发现一句代码， [cpp] view plaincopyprint? #includemain.h #includeAppDelegate.h #includeCCEGLView.h USING_NS_CC; int APIENTRY_tWinMain( HINSTANCE

http://blog.csdn.net/itcastcpp/article/details/18608437

背景

在学习cocos2dx时，我们在main函数中发现一句代码，

[cpp] view plaincopyprint?

1. #include "main.h"
2. #include "AppDelegate.h"
3. #include "CCEGLView.h"
5. USING_NS_CC;
7. int APIENTRY _tWinMain(HINSTANCE hInstance,
8. HINSTANCE hPrevInstance,
9. LPTSTR lpCmdLine,
10. int nCmdShow)
11. {
12. UNREFERENCED_PARAMETER(hPrevInstance);
13. UNREFERENCED_PARAMETER(lpCmdLine);
15. // create the application instance
16. AppDelegate app;
17. CCEGLView* eglView = CCEGLView::sharedOpenGLView();
18. eglView->setViewName("CrazyMario");
19. eglView->setFrameSize(480, 320);
20. return CCApplication::sharedApplication()->run();
21. }

#include "main.h"
#include "AppDelegate.h"
#include "CCEGLView.h"

USING_NS_CC;

int APIENTRY _tWinMain(HINSTANCE hInstance,
                       HINSTANCE hPrevInstance,
                       LPTSTR    lpCmdLine,
                       int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // create the application instance
    AppDelegate app;
    CCEGLView* eglView = CCEGLView::sharedOpenGLView();
    eglView->setViewName("CrazyMario");
    eglView->setFrameSize(480, 320);
    return CCApplication::sharedApplication()->run();
}

那就是eglView->setFrameSize(480,320)，这句代码设置了窗口的大小，一般说来手机游戏需要全屏显示，所以对于不同分辨率的手机，setFrameSize要求不一样的。这样是不是很崩溃？因为我们代码里很多地方可能也要改，图片大小可能也要改，那怎么办呢？

其实cocos2dx已经为我们做好了这一切

结局方案

这个方案就是调用eglView->setDesignResolutionSize(480, 320, kResolutionShowAll);来告诉cocos2dx，我的程序是按照480，320来设计的，那么setFrameSize如果不是480，320那么cocos2dx会按照比例给我们做适配，不用我们做别的事情。

在超级马里奥这个游戏里，在AppDelegate中已经调用了setDesignResolutionSize函数设置设计大小为480，320

那么在setFrameSize不同的情况下，也不会引起图片比例不合适的情况，只是窗口大小会发生变化而已

在480*320的情况下

在960*640的情况下，只是界面变大了，图片没有任何的不适合

setDesignResolutionSize的参数

第三个参数的取值范围如下：

[cpp] view plaincopyprint?

1. enum ResolutionPolicy
2. {
3. // The entire application is visible in the specified area without trying to preserve the original aspect ratio.
4. // Distortion can occur, and the application may appear stretched or compressed.
5. kResolutionExactFit,
6. // The entire application fills the specified area, without distortion but possibly with some cropping,
7. // while maintaining the original aspect ratio of the application.
8. kResolutionNoBorder,
9. // The entire application is visible in the specified area without distortion while maintaining the original
10. // aspect ratio of the application. Borders can appear on two sides of the application.
11. kResolutionShowAll,
12. // The application takes the height of the design resolution size and modifies the width of the internal
13. // canvas so that it fits the aspect ratio of the device
14. // no distortion will occur however you must make sure your application works on different
15. // aspect ratios
16. kResolutionFixedHeight,
17. // The application takes the width of the design resolution size and modifies the height of the internal
18. // canvas so that it fits the aspect ratio of the device
19. // no distortion will occur however you must make sure your application works on different
20. // aspect ratios
21. kResolutionFixedWidth,
23. kResolutionUnKnown,
24. };

enum ResolutionPolicy
{
    // The entire application is visible in the specified area without trying to preserve the original aspect ratio.
    // Distortion can occur, and the application may appear stretched or compressed.
    kResolutionExactFit,
    // The entire application fills the specified area, without distortion but possibly with some cropping,
    // while maintaining the original aspect ratio of the application.
    kResolutionNoBorder,
    // The entire application is visible in the specified area without distortion while maintaining the original
    // aspect ratio of the application. Borders can appear on two sides of the application.
    kResolutionShowAll,
    // The application takes the height of the design resolution size and modifies the width of the internal
    // canvas so that it fits the aspect ratio of the device
    // no distortion will occur however you must make sure your application works on different
    // aspect ratios
    kResolutionFixedHeight,
    // The application takes the width of the design resolution size and modifies the height of the internal
    // canvas so that it fits the aspect ratio of the device
    // no distortion will occur however you must make sure your application works on different
    // aspect ratios
    kResolutionFixedWidth,

    kResolutionUnKnown,
};

kResolutionExactFit：会靠拉伸来填满屏幕，本例来说背景图会变形来填充屏幕，因为1024:768=1.3， 480:320=1.5，宽高比不同，图片也就无法等比缩放来填满屏幕，只能变形了。
kResolutionNoBorder： 看不到黑边，实际就是宽高等比缩放，但缩放比例取宽比和高比之中大的那一个。
kResolutionShowAll：全部显示，可以理解为保证内容都显示在屏幕之内，实际也是宽高等比缩放，但缩放比例取宽比和高比之中小的那一个。