Cocos2dx-截屏并设置图片尺寸

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原文地址: http://www.cocos2dev.com/?p=522

前几天添加微信图片分享的时候，发现全屏截图超出了微信的数据包大小，所以截屏的时候可以考虑缩小尺寸到0.5倍。

下面的截屏代码：

    void LHUtil::screenShoot()
    {
        Size visibleSize = Director::getInstance()->getVisibleSize();  

        //定义一个屏幕大小的渲染纹理
        RenderTexture* renderTexture = RenderTexture::create(visibleSize.width * .5, visibleSize.height * .5, Texture2D::PixelFormat::RGBA8888);  

        Scene* curScene = Director::getInstance()->getRunningScene();
        Point ancPos = pCurScene->getAnchorPoint();  

        //渲染纹理开始捕捉
        renderTexture->begin();  

        // 缩小屏幕截屏区域
        curScene->setScale(.5);
        curScene->setAnchorPoint(cocos2d::Point(0, 0));  

        //绘制当前场景
        curScene->visit();  

        //结束
        renderTexture->end();  

        //保存png
        renderTexture->saveToFile("screenshoot.png", Image::Format::PNG);  

        // 恢复屏幕尺寸
        curScene->setScale(1);
        curScene->setAnchorPoint(ancPos);
        CC_SAFE_DELETE(curScene);
    }  

上面是cocos2dx的获取截屏的方法。

我顺便写下如何用OC的UIGraphicsBeginImageContext获取UIView转化成UIImage.

下面是ios方法：

    -(void)screenShot:(CGRect)rect{
        // 开始设置截屏区域
        UIGraphicsBeginImageContextWithOptions(rect.size, YES, 0);
        [[self.view layer] renderInContext:UIGraphicsGetCurrentContext()];
        UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();  

        // 获取image，可以根据需要进行尺寸修改
        CGImageRef imageRef = viewImage.CGImage;
        CGImageRef imageRefRect =CGImageCreateWithImageInRect(imageRef, rect);
        UIImage *image = [[UIImage alloc] initWithCGImage:imageRefRect];  

        // 保存图片到相册, 这里会提示用户授权，不需要保存的话，可以取消
        UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);  

        // 获取Documents目录
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"temScreenShot.png"];  

        // 保存image到Documents目录
        NSData *imageData = UIImagePNGRepresentation(image);
        [imageData writeToFile:savedImagePath atomically:YES];
        CGImageRelease(imageRefRect);
    }