简易的“虚拟头盔”实现

时间：2015-03-09 08:13:29 阅读：271 评论：0 收藏：0 [点我收藏+]

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头盔原理很简单，大致就是使用两个透镜，缩短眼睛的焦距，将两个眼睛看到的东西合二为一从而产生双屏3D效果。

于是开始设想：既然有了3D效果，为了达到更加沉浸的体验，为何不将头部的运动也映射到虚拟世界中去呢？抱着这个想法，我们做了如下尝试：

把头部数据（如旋转角、俯仰角等等）用陀螺仪接收传回电脑，为了简单起见快速出效果，直接手机，然后在手机端写了个app，负责使用wifi发送陀螺仪数据到pc，pc接收到数据之后，我写了个dll，共享内存的，不断更新那一块内存，宿主程序使用的时候，只需要call那块数据即可，方法非常简单。

安卓客户端我不懂，所以是我同学写的。我只说c++ dll的代码，为了方便起见我是用了一个简单sender来模拟陀螺仪发回的数据。

//sender
#include <iostream>
#include <Windows.h>
#include <tchar.h>
#include <ctime>
using namespace std;

struct DataStruct
{
    float x;
    float y;
    float z;
};

#define BUF_SIZE 1024
TCHAR szName[]=TEXT("Global\\MyFileMappingObject"); 

int main()
{
    HANDLE hMapFile;
    float* pBuf;

    hMapFile = CreateFileMapping(
        INVALID_HANDLE_VALUE,  
        NULL,                 
        PAGE_READWRITE,         
        0,                     
        BUF_SIZE,            
        szName);                

    if (hMapFile == NULL)
    {
        _tprintf(TEXT("Could not create file mapping object (%d).\n"),
            GetLastError());
        return 1;
    }
    pBuf = (float*) MapViewOfFile(hMapFile, 
        FILE_MAP_ALL_ACCESS, 
        0,
        0,
        BUF_SIZE);

    if (pBuf == NULL)
    {
        _tprintf(TEXT("Could not map view of file (%d).\n"),
            GetLastError());

        CloseHandle(hMapFile);

        return 1;
    }
    while(1)
    {
        float s[3] = {1.0f,33.2f,12.3f};
        size_t a = sizeof(s);
        srand(clock());
        *s = rand() / (double)(3.2);
        *(s+1) = rand() / (double)(3.2);
        *(s+2) = rand() / (double)(3.2);
        cout<<s[0]<<" "<<s[1]<<" "<<s[2]<<endl;
        memcpy((PVOID)pBuf, (void*)s, sizeof(s));
    }
}

接收dll代码

#include <windows.h>
#include <string.h>
#include <string>
#include <iostream>
#include <tchar.h>
#include "recevedate.h"
using namespace std;



#define BUF_SIZE 1024
TCHAR szName[]=TEXT("Global\\MyFileMappingObject"); 
HANDLE hMapFile;
float* pBuf;

int dll_data_init()
{
        hMapFile = CreateFileMapping(
        INVALID_HANDLE_VALUE,    // use paging file
        NULL,                    // default security
        PAGE_READWRITE,          // read/write access
        0,                       // maximum object size (high-order DWORD)
        BUF_SIZE,                // maximum object size (low-order DWORD)
        szName);                 // name of mapping object

    if (hMapFile == NULL)
    {
        _tprintf(TEXT("Could not create file mapping object (%d).\n"),
            GetLastError());
        return -1;
    }
    pBuf = (float*) MapViewOfFile(hMapFile,   // handle to map object
        FILE_MAP_ALL_ACCESS, // read/write permission
        0,
        0,
        BUF_SIZE);

    if (pBuf == NULL)
    {
        _tprintf(TEXT("Could not map view of file (%d).\n"),
            GetLastError());

        CloseHandle(hMapFile);

        return -1;
    }
    return 0;
}

float get_x()
{
    return pBuf[0];
}

float get_y()
{
    return pBuf[1];
}

float get_z()
{
    return pBuf[2];
}

float get_dx()
{
    return pBuf[3];
}

float get_dy()
{
    return pBuf[4];
}

float get_dz()
{
    return pBuf[5];
}

void dll_data_ter()
{
    UnmapViewOfFile(pBuf);
    CloseHandle(hMapFile);
}

初始化调用int dll_data_init()函数，退出时调用void dll_data_ter()，中间直接获取指定的数据即可。

using UnityEngine;
using System.Collections;
using System;
using System.Runtime.InteropServices; 

public class dll : MonoBehaviour {
    [DllImport("daterecive.dll")]
    public static extern int dll_data_init();
    [DllImport("daterecive.dll")]
    public static extern void dll_data_ter ();
    [DllImport("daterecive.dll")]
    public static extern float get_x ();
    [DllImport("daterecive.dll")]
    public static extern float get_y ();
    [DllImport("daterecive.dll")]
    public static extern float get_z ();
    // Use this for initialization
    void Start () {
        dll_data_init ();
    }
    
    // Update is called once per frame
    void Update () {

        //getdata ();
    }



    void OnApplicationQuit()
    {
        dll_data_ter ();
    }
}