【获取地图中的可行区域层】

#include "HelloWorldScene.h"

USING_NS_CC;

Scene* HelloWorld::createScene()
{
    // ‘scene‘ is an autorelease object
    auto scene = Scene::create();

    // ‘layer‘ is an autorelease object
    auto layer = HelloWorld::create();

    // add layer as a child to scene
    scene->addChild(layer);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }

    Size visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();

    /////////////////////////////
    // 3. add your codes below...

    // add "HelloWorld" splash screen"
    auto sprite = Sprite::create("HelloWorld.png");

    // position the sprite on the center of the screen
    sprite->setPosition(Vec2(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));

    // add the sprite as a child to this layer
    this->addChild(sprite, 0);

    float scaleFactor = CCDirector::sharedDirector()->getContentScaleFactor();
    auto listener = EventListenerTouchOneByOne::create();
    listener->onTouchBegan = [=](Touch * touch, Event* event) {
        auto pointLocation = touch->getLocation();
        if (sprite->getBoundingBox().containsPoint(pointLocation)) {
            auto point = sprite->convertToNodeSpace(touch->getLocation());
            unsigned int x = point.x * scaleFactor, y = (sprite->getContentSize().height - point.y) * scaleFactor;
            Color4B c = { 0, 0, 0, 0 };
            auto img = new Image();
            img->initWithImageFile(CCFileUtils::getInstance()->fullPathForFilename("HelloWorld.png"));
            unsigned char *data_ = img->getData();
            unsigned int *pixel = (unsigned int *)data_;
            pixel = pixel + (y *(int)(sprite->getContentSize().height*scaleFactor)) + x;
            c.r = *pixel & 0xff;
            c.g = (*pixel >> 8) & 0xff;
            c.b = (*pixel >> 16) & 0xff;
            c.a = (*pixel >> 24) & 0xff;
            if (c.a == 0) { return false; }
            else { return true; }
        }
        return true;
    };
    _eventDispatcher->addEventListenerWithSceneGraphPriority(listener, this);

    return true;
}