创建跨平台c ++触摸管理器。在c ++中传递Objective-c对象涉及代码

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所以我正在尝试创建一个可以跨平台（ios，android等）使用的多点触控类。目标是引擎不需要知道平台以获得更新的触摸数据。

现在我正在进行一般设计，并且专门实现iOS方面。 Android等方面将会更晚。

为了做到这一点，我试图使用委托模式。实际上只有两个接口项。

有一个方法更新（浮点dt）用dt在每个新帧上调用。然后，此方法将返回有关所有触摸的信息的c ++结构，或者可能设置可以访问的属性。我不确定。

在iOS端，唯一需要从外部调用的其他函数是touchesDown，它传入UITouches的NSSet *和它们所在的UIView。

这是我到目前为止所使用的设计

Multitouch
    PlatformTouchManager.h (C++ Abstract Class with Update)
    iOS
        iOSMultiTouch.cpp (Objective-c++)
        iOSMultiTouch.hpp (Objective-c++ Class inheriting PlatformTouchManager)
    MultTouch.cpp (C++)
    MultiTouch.h (C++ class)

这是PlatformTouchManager.h

#define MAX_TOUCHES 5
#define PLATFORM_iOS
//#define PLATFORM_ANDROID

class PlatformTouchManager {
public:
    // Update All The Events
    virtual void update(float time) = 0;
};

当然还有Multitouch.h

class Multitouch {
private:
    PlatformTouchManager* manager;
public:
    Multitouch() {
#ifdef PLATFORM_iOS
        manager = new iOSMultiTouch();
#endif
    }
    ~Multitouch() {
        delete manager;
    }

    Multitouch(const Multitouch&) = delete;

    void update(float dt);

    void* getManager() {
        return manager;
    }
};

最后是iOSMultiTouch.hpp

#include <stdio.h>
#include "../PlatformTouchManager.h"
#include <set>
#import <UIKit/UIKit.h>

class iOSMultiTouch: public PlatformTouchManager {
public:
    // Initializer
    iOSMultiTouch();

    // Destructor
    ~iOSMultiTouch();

    // Update All The Events
    void update(float time);

    // Touch Down Set
    void touchesDown(id<NSSet> set, id<UIView> view);
};

值得注意的是，此代码包含在MultiTouch.h（c ++）中，而我的本机视图代码是objective-c ++。

因此，跨平台引擎创建了一个Multitouch对象，保持引用并且每个帧调用更新。

我想像iOS UIView将从跨平台引擎获得Multitouch*。将其投射到iOSMultiTouch*对象并在代表上调用touchesDown:(NSSet *)touches withEvent:(IUView *)view。

我这样做有一个严重的问题。

如果我尝试在iOSMUltiTouch.hpp中导入UIKit，则会导致构建混乱，因此看起来我只能在源文件中导入它。因此我的降落方法需要无效touchesDown(void* touches, void* view);.

问题在于实现这一点，因为当我尝试将这些void*指针转换为正确的类型时，我得到警告Cast of C pointer type void* to objective-c pointer type id requires a bridged cast。

我知道这里有一些ARC问题，因为ARC在转换成原始指针时无法跟踪这些事情，但我该如何解决这个问题呢？

iOSTouchManager确实需要保持对UITouch对象的强引用，直到释放触摸的帧之后。

我该如何实现这个演员？有没有不同的方法我应该设计我的类来使这更容易？

对于那些想知道这些是弹出的错误你应该从iOSMultiTouch.hpp导入uikit的人

Parse Issue

Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:512:1: Expected unqualified-id
../Multitouch/MultiTouch.cpp:9:10: In file included from ../Multitouch/MultiTouch.cpp:9:
../Multitouch/MultiTouch.h:15:10: In file included from ../Multitouch/MultiTouch.h:15:
../Multitouch/iOS/iOSMultiTouch.hpp:15:9: In file included from ../Multitouch/iOS/iOSMultiTouch.hpp:15:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIKit.h:8:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIKit.h:8:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:8:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:8:

Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSZone.h:9:1: Expected unqualified-id
../Multitouch/MultiTouch.cpp:9:10: In file included from ../Multitouch/MultiTouch.cpp:9:
../Multitouch/MultiTouch.h:15:10: In file included from ../Multitouch/MultiTouch.h:15:
../Multitouch/iOS/iOSMultiTouch.hpp:15:9: In file included from ../Multitouch/iOS/iOSMultiTouch.hpp:15:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIKit.h:8:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIKit.h:8:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:10:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:10:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSArray.h:5:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSArray.h:5:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:8:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:8:

Semantic Issues

Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:514:9: Unknown type name 'NSString'
../Multitouch/MultiTouch.cpp:9:10: In file included from ../Multitouch/MultiTouch.cpp:9:
../Multitouch/MultiTouch.h:15:10: In file included from ../Multitouch/MultiTouch.h:15:
../Multitouch/iOS/iOSMultiTouch.hpp:15:9: In file included from ../Multitouch/iOS/iOSMultiTouch.hpp:15:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIKit.h:8:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIKit.h:8:
Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:8:9: In file included from Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:8:
答案

问题

你有很多错误，因为你在C ++文件（UIKit）中导入了iOS框架（iOSMultiTouch.cpp）。

解

对于需要导入iOS框架的实现文件，您必须使用.mm而不是.cpp扩展。 .cpp是C ++扩展，而不是Objective-C ++扩展。

在这种情况下，您需要将iOSMultiTouch.cpp重命名为iOSMultiTouch.mm。用Objective-C指针替换void *，它将按预期工作。

Utils.h将保留与Objective-C无关的任何内容，并且可以在任何地方使用。 Utils.mm用于处理Objective-C部件。

Utils.h

PlatformTouchManager* GetIOSTouchManager();

u替LS.妈妈

#include "Utils.h"
#include "iOSMultiTouch.hpp"

PlatformTouchManager* GetIOSTouchManager() {
  return new iOSMultiTouch();
};

Multitouch.h

#include "Utils.h"
// Other include

class Multitouch {
  private:
  PlatformTouchManager* manager;
  public:
  Multitouch() {
#ifdef PLATFORM_iOS
    manager = GetIOSTouchManager();
#endif
  }
  ~Multitouch() {
    delete manager;
  }

  Multitouch(const Multitouch&) = delete;

  void update(float dt);

  PlatformTouchManager* getManager() {
    return manager;
  }
};

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