将多个变量从C ++发送到Swift

如何解决将多个变量从C ++发送到Swift

我是iOS开发的新手，我正在尝试制作一个可以通过相机进行某种图像处理的应用程序。我正在使用OpenCV进行图像处理，这是C ++。我成功制作了一个执行此操作的应用程序，但是我想将一些信息从C ++代码发送到Swift，以便可以在用户界面中显示它。因此，我需要将多个变量从C ++返回给Swift。我尝试使用元组，但没有成功。我需要更改或添加哪些文件才能从C ++向Swift返回多个内容？预先感谢！

这是我的代码的制作方式：

在ViewController.swift文件中，我有以下代码：

import UIKit
import AVFoundation

class ViewController: UIViewController,AVCaptureVideoDataOutputSampleBufferDelegate {
    @IBOutlet weak var imageView: UIImageView!
    @IBOutlet weak var frameRate: UITextField!
    
    private var captureSession: AVCaptureSession = AVCaptureSession()
    private let videoDataOutput = AVCaptureVideoDataOutput()
    
    
    private func addCamerainput() {
        guard let device = AVCaptureDevice.discoverySession(deviceTypes: [.builtInWideAngleCamera],mediaType: .video,position: .back).devices.first else {
            fatalError("no camera found")
        }
        let cameraInput = try! AVCaptureDeviceInput(device: device)
        self.captureSession.sessionPreset = .vga640x480
        self.captureSession.addInput(cameraInput)
    }
    
    private func getFrames() {
        videoDataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as Nsstring) : NSNumber(value: kCVPixelFormatType_32BGRA)] as [String: Any]
        videoDataOutput.alwaysdiscardsLateVideoFrames = true
        videoDataOutput.setSampleBufferDelegate(self,queue: dispatchQueue(label: "camera.frame.processing.queue"))
        self.captureSession.addOutput(videoDataOutput)
        
        guard let connection = self.videoDataOutput.connection(with: AVMediaType.video),connection.isVideoOrientationSupported else { return }
        connection.videoOrientation = .portrait
    }
    
    func captureOutput(
        _ output: AVCaptureOutput,didOutput sampleBuffer: CMSampleBuffer,from connection: AVCaptureConnection) {
        
        // Here we can process the frame
        guard let  imageBuffer = CMSampleBufferGetimageBuffer(sampleBuffer) else { return }
        CVPixelBufferLockBaseAddress(imageBuffer,CVPixelBufferLockFlags.readOnly)
        let baseAddress = CVPixelBufferGetBaseAddress(imageBuffer)
        let bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer)
        let width = CVPixelBufferGetWidth(imageBuffer)
        let height = CVPixelBufferGetHeight(imageBuffer)
        let colorSpace = CGColorSpaceCreateDeviceRGB()
        var bitmapInfo: UInt32 = CGBitmapInfo.byteOrder32Little.rawValue
        bitmapInfo |= CGImageAlphaInfo.premultipliedFirst.rawValue & CGBitmapInfo.alphaInfoMask.rawValue
        let context = CGContext(data: baseAddress,width: width,height: height,bitsPerComponent: 8,bytesPerRow: bytesPerRow,space: colorSpace,bitmapInfo: bitmapInfo)
        guard let quartzImage = context?.makeImage() else { return }
        CVPixelBufferUnlockBaseAddress(imageBuffer,CVPixelBufferLockFlags.readOnly)
        let image = UIImage(cgImage: quartzImage)
        
        let processed_image = imageProcessingBridge().imageProcessing(in: image)
        
        dispatchQueue.main.async {
            self.imageView.image = processed_image
        }
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        self.addCamerainput()
        self.getFrames()
        self.captureSession.startRunning()
    }


}

对于图像处理，我将这段代码保存在名为imageProcessing.cpp的文件中：

#include "imageProcessing.hpp"

using namespace cv;
using namespace std;

Mat image_processing::detect_line(Mat image) {
    // do some image processing with image
    return image;
}

，并将此代码存储在名为imageProcessing.hpp的文件中：

#ifndef imageProcessing_hpp
#define imageProcessing_hpp

#include <stdio.h>
#include <opencv2/opencv.hpp>

using namespace cv;
using namespace std;

class image_processing {
public:
    Mat detect_line(Mat image);
};

#endif /* imageProcessing_hpp */

对于C ++和Swift之间的链接，我有2个文件，分别是imageProcessingBridge.h和imageProcessingBridge.mm：

#ifndef imageProcessingBridge_h
#define imageProcessingBridge_h

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface imageProcessingBridge : NSObject

- (UIImage *) imageProcessingIn: (UIImage *) image;

@end

#endif /* imageProcessingBridge_h */

和：

#import <opencv2/opencv.hpp>
#import <opencv2/imgcodecs/ios.h>
#import <Foundation/Foundation.h>
#import "imageProcessingBridge.h"
#import "imageProcessing.hpp"

@implementation imageProcessingBridge

- (UIImage *) imageProcessingIn:(UIImage *)image {
    
    // convert UI image to mat
    cv::Mat opencvImage;
    UIImagetoMat(image,opencvImage,true);
    
    // convert colorspace
    cv::Mat convertedColorSpaceImage;
    cv::cvtColor(opencvImage,convertedColorSpaceImage,CV_RGBA2RGB);
    
    // Run image processing algorithm
    image_processing imageProcessing;
    cv::Mat processedImage = imageProcessing.detect_line(convertedColorSpaceImage);
    
    // convert mat to UI image and return it to the caller
    return MatToUIImage(processedImage);
}
@end