build_native.py文件分析(2)

def build(ndk_build_param,android_platform,build_mode):

    ////获取ndk_root -- NDK_ROOT = os.environ['NDK_ROOT']
    ndk_root = check_environment_variables() //获取ndk_root
    sdk_root = None
    select_toolchain_version() //选择编译工具版本
    
    //获取当前目录
    current_dir = os.path.dirname(os.path.realpath(__file__))

    //获取cocos_root库根目录，这个因为我们创建工程时拷贝了
    //库源码，所以cocos_root目录使用的是当前目录相对目录
    //如果我们的工程和库相对位置不是这样的，那我们只需要
    //把此处修改一些就可以了。
    //例如cocos_root = os.path.join("E:\otherpro\cocos2d-x-3.0\project\starGame\wipeStar\cocos2d")
    cocos_root = os.path.join(current_dir, "../cocos2d")

    //android 工程的根目录
    app_android_root = current_dir

    //拷贝资源文件，即把Resources -->> assets
    copy_resources(app_android_root)
    
    if android_platform is not None:
                                //获取SDK路径 --  SDK_ROOT = os.environ['ANDROID_SDK_ROOT']
				sdk_root = check_environment_variables_sdk()
				if android_platform.isdigit():
						android_platform = 'android-'+android_platform
				else:
						print 'please use vaild android platform'
						exit(1)
		
    if build_mode is None:
    	  build_mode = 'debug'
    elif build_mode != 'release':
        build_mode = 'debug'
    
    do_build(cocos_root, ndk_root, app_android_root,ndk_build_param,sdk_root,android_platform,build_mode)

    -->>do_build分析：

    def do_build(cocos_root, ndk_root, app_android_root,ndk_build_param,sdk_root,android_platform,build_mode):

            //得到NDK下ndk-build的路径
	    ndk_path = os.path.join(ndk_root, "ndk-build")

	    # windows should use ";" to seperate module paths
	    platform = sys.platform
	    //生成ndk_module_path参数，也就是执行ndk-build是需要NDK_MODULE_PATH路径，
	    //这里我们也可以根据自己的需求修改

	    if platform == 'win32':
		ndk_module_path = 'NDK_MODULE_PATH=%s;%s/external;%s/cocos' % (cocos_root, cocos_root, cocos_root)
	    else:
		ndk_module_path = 'NDK_MODULE_PATH=%s:%s/external:%s/cocos' % (cocos_root, cocos_root, cocos_root)
		
	    num_of_cpu = get_num_of_cpu()
		
	    //根据传进来的参数，生成编译命令，ndk_build_param(我们执行脚本时-n指定的参数)
	    //其实这个参数都是传给ndk-build命令的。
	    if ndk_build_param == None:
		command = '%s -j%d -C %s %s' % (ndk_path, num_of_cpu, app_android_root, ndk_module_path)
	    else:
		command = '%s -j%d -C %s %s %s' % (ndk_path, num_of_cpu, app_android_root, ''.join(str(e) for e in ndk_build_param), ndk_module_path)
	    if os.system(command) != 0:
		raise Exception("Build dynamic library for project [ " + app_android_root + " ] fails!")
	    elif android_platform is not None:
		  sdk_tool_path = os.path.join(sdk_root, "tools/android")
		  cocoslib_path = os.path.join(cocos_root, "cocos/2d/platform/android/java")
		  command = '%s update lib-project -t %s -p %s' % (sdk_tool_path,android_platform,cocoslib_path) 
		  if os.system(command) != 0:
			  raise Exception("update cocos lib-project [ " + cocoslib_path + " ] fails!")  	  
		  command = '%s update project -t %s -p %s -s' % (sdk_tool_path,android_platform,app_android_root)
		  if os.system(command) != 0:
			  raise Exception("update project [ " + app_android_root + " ] fails!")    	  	  
		  buildfile_path = os.path.join(app_android_root, "build.xml")
		  command = 'ant clean %s -f %s -Dsdk.dir=%s' % (build_mode,buildfile_path,sdk_root)
		  
		  //执行命令
		  os.system(command)