漫谈WinCE的手写识别技术(二)

//========================================================================
//TITLE:
//    漫谈WinCE的手写识别技术(二)
//AUTHOR:
//    norains
//DATE:
//    Thursday  25-January -2007
//Environment:
//  EVC4.0 + Standard SDK
//========================================================================
  
  在第一章的时候,已经介绍了识别的一般性过程,对于实际运用来说,是完全可行的;但从便利性角度出发,却不免显得烦琐:每次输入笔画都需留意点阵是否屏幕坐标系,每次读取返回的字符总要分配内存然后获取等等,诸如总总,代码写一次还好,如果多处运用多次编写多方维护,实在不是一件快乐的事情.
  
  而我,最讨厌做复杂又要花费脑筋的东东;所以,为了让自己感觉得写代码是一件快乐的事情,自己又很高兴地将识别过程封装为一个类.至于是否达到简便的效果,不敢祈求大家苟同,只愿自己舒坦即可.

 

/**/ //////////////////////////////////////////////////////////////////////
//  Recognizer.h: interface for the CRecognizer class.                //
/**/ //////////////////////////////////////////////////////////////////////

#ifndef RECOGNIZER_H
#define  RECOGNIZER_H

// ===========================================================================
// Include file
#include  " recog.h "

// =====================================================================================
// Choose the build type for the recognizing function
// --------------------------------------------------------------------------
#define  RECOGNIZE_FUNCTION_FROM_DLL
// #define RECOGNIZE_FUNCTION_FROM_LIB

#ifndef RECOGNIZE_FUNCTION_FROM_LIB
    #ifndef RECOGNIZE_FUNCTION_FROM_DLL
         #define  RECOGNIZE_FUNCTION_FROM_DLL 
     #endif
#endif

#ifdef RECOGNIZE_FUNCTION_FROM_DLL
     #define  RECOGNIZE_DLL_PATH                TEXT("/WINDOWS/hwxcht.dll")
#endif
// =====================================================================================



// -----------------------------------------------------------------------------------
// The data type

// The scale type for the coordinate
enum  ScaleType
... {
    SCALE_APPWND,
    SCALE_SCREEN
} ;
// ------------------------------------------------------------------------------
class  CRecognizer  
... {
public:
    BOOL InputStroke(POINT *lpPnt, int iCount, ScaleType scale);
    CRecognizer();
    virtual ~CRecognizer();
    int GetCharacter(WCHAR *pWchar, int iCount);
    BOOL EndRecognize();
    BOOL BeginRecognize();
    BOOL Initialize(HWND hWnd,const RECT *prcWnd,ScaleType scale);
protected:
    HRC m_hrc;
    HWXGUIDE m_hwxGuide;
    HWND m_hWndRecog;
    ALC m_alc;

#ifdef RECOGNIZE_FUNCTION_FROM_DLL    
    typedef BOOL (WINAPI *DLL_HWXCONFIG)(void);    
    typedef HRC (WINAPI *DLL_HWXCREATE)(HRC = NULL);
    typedef BOOL (WINAPI *DLL_HWXSETGUIDE)(HRC ,HWXGUIDE*);
    typedef BOOL (WINAPI *DLL_HWXALCVALID)(HRC,ALC);
    typedef BOOL (WINAPI *DLL_HWXALCPRIORITY)(HRC,ALC);
    typedef BOOL (WINAPI *DLL_HWXSETCONTEXT)(HRC,WCHAR);
    typedef BOOL (WINAPI *DLL_HWXINPUT)(HRC,POINT*,UINT, DWORD);
    typedef BOOL (WINAPI *DLL_HWXENDINPUT)(HRC);
    typedef BOOL (WINAPI *DLL_HWXPROCESS)(HRC);
    typedef INT (WINAPI *DLL_HWXRESULTSAVAILABLE)(HRC);
    typedef INT32 (WINAPI *DLL_HWXGETRESULTS)(HRC, UINT, UINT, UINT, HWXRESULTS*);
    typedef BOOL (WINAPI *DLL_HWXDESTROY)(HRC);
    DLL_HWXCONFIG                HWXCONFIG;
    DLL_HWXCREATE                HWXCREATE;
    DLL_HWXSETGUIDE                HWXSETGUIDE;    
    DLL_HWXALCVALID                HWXALCVALID;    
    DLL_HWXALCPRIORITY            HWXALCPRIORITY;
    DLL_HWXSETCONTEXT            HWXSETCONTEXT;
    DLL_HWXINPUT                HWXINPUT;
    DLL_HWXPROCESS                HWXPROCESS;
    DLL_HWXRESULTSAVAILABLE        HWXRESULTSAVAILABLE;
    DLL_HWXGETRESULTS            HWXGETRESULTS;
    DLL_HWXDESTROY                HWXDESTROY;
    DLL_HWXENDINPUT                HWXENDINPUT;
#endif //RECOGNIZE_FUNCTION_FROM_DLL


#ifdef RECOGNIZE_FUNCTION_FROM_LIB
    #define HWXCONFIG(void)                                            HwxConfig(void)
    #define HWXCREATE(hrc)                                            HwxCreate(hrc)
    #define HWXSETGUIDE(hrc,lpGuide)                                HwxSetGuide(hrc,lpGuide)
    #define HWXALCVALID(hrc,alc)                                    HwxALCValid(hrc,alc)
    #define HWXALCPRIORITY(hrc,alc)                                    HwxALCPriority(hrc,alc)
    #define HWXSETCONTEXT(hrc,wContext)                                HwxSetContext(hrc,wContext)
    #define HWXINPUT(hrc,lppnt,upoints,timestamp)                    HwxInput(hrc,lppnt,upoints,timestamp)
    #define HWXPROCESS(hrc)                                            HwxProcess(hrc)
    #define HWXRESULTSAVAILABLE(hrc)                                HwxResultsAvailable(hrc)
    #define HWXGETRESULTS(hrc,cAlt,iFirst,cBoxRes,rgBoxResults)        HwxGetResults(hrc,cAlt,iFirst,cBoxRes,rgBoxResults)
    #define HWXDESTROY(hrc)                                            HwxDestroy(hrc)
    #define HWXENDINPUT(hrc)                                        HwxEndInput(hrc)
#endif //RECOGNIZE_FUNCTION_FROM_LIB
} ;



// ============================================================================================
#endif   //  !defined RECOGNIZER_H

 

 

/**/ //////////////////////////////////////////////////////////////////////
//  Recognizer.cpp: implementation of the CRecognizer class.          //
/**/ //////////////////////////////////////////////////////////////////////

#include  " stdafx.h "
#include  " Recognizer.h "

// -------------------------------------------------------------------
// Macro define

// The default value of hwxGuide
#define  DEFAULT_HWXGUIDE_CHORZBOX                1
#define  DEFAULT_HWXGUIDE_CVERTBOX                1
#define  DEFAULT_HWXGUIDE_CXOFFSET                1
#define  DEFAULT_HWXGUIDE_CYOFFSET                1

// The default value of ALC
#define  DEFAULT_ALC                                ALC_KANJI_ALL




// --------------------------------------------------------------------
/**/ //////////////////////////////////////////////////////////////////////
//  Construction/Destruction
/**/ //////////////////////////////////////////////////////////////////////

CRecognizer::CRecognizer()
... {
    m_alc = NULL;
    m_hrc = NULL;
    m_hWndRecog = NULL;
    memset(&m_hwxGuide,0,sizeof(m_hwxGuide));
}

CRecognizer:: ~ CRecognizer()
... {

}

// -----------------------------------------------------------------------
// Descriptiong:
//     Initialize the recognizer
//
// Parameter:
//     hWnd: [in] The handle of window to be recognized
//     rcWnd: [in] The window area to be recognized
//     scale: [in] The scale base of prcWnd point
// -----------------------------------------------------------------------
BOOL CRecognizer::Initialize(HWND hWnd, const  RECT  * prcWnd,ScaleType scale)
... {
    m_hWndRecog = hWnd;

    m_alc = DEFAULT_ALC;

    RECT rcWnd = ...{0};
    switch(scale)
    ...{
        case SCALE_APPWND:
        ...{        
            rcWnd = *prcWnd;
            rcWnd.left *= 4;
            rcWnd.right *= 4;
            rcWnd.top *= 4;
            rcWnd.bottom *= 4;
            MapWindowPoints(hWnd,HWND_DESKTOP,(LPPOINT)(&rcWnd),(sizeof(RECT)/sizeof(POINT)));
            break;
        }
        case SCALE_SCREEN:
        ...{
            rcWnd = *prcWnd;
            break;
        }
    }

    m_hwxGuide.cHorzBox = DEFAULT_HWXGUIDE_CHORZBOX;
    m_hwxGuide.cVertBox = DEFAULT_HWXGUIDE_CVERTBOX;
    m_hwxGuide.xOrigin = rcWnd.left;
    m_hwxGuide.yOrigin = rcWnd.top;
    m_hwxGuide.cxBox = rcWnd.right - rcWnd.left;
    m_hwxGuide.cyBox = rcWnd.bottom - rcWnd.top;
    m_hwxGuide.cxOffset = DEFAULT_HWXGUIDE_CXOFFSET;
    m_hwxGuide.cyOffset = DEFAULT_HWXGUIDE_CYOFFSET;
    m_hwxGuide.cxWriting = (rcWnd.right - rcWnd.left) - m_hwxGuide.cxOffset * 2;
    m_hwxGuide.cyWriting = (rcWnd.bottom - rcWnd.top) - m_hwxGuide.cyOffset * 2;
    m_hwxGuide.nDir = HWX_HORIZONTAL;

#ifdef RECOGNIZE_FUNCTION_FROM_DLL
    HINSTANCE hInstDll;
    hInstDll = LoadLibrary(RECOGNIZE_DLL_PATH);
    if(hInstDll != NULL)
    ...{
        HWXCONFIG = (DLL_HWXCONFIG) GetProcAddress(hInstDll,TEXT("HwxConfig"));
        HWXCREATE = (DLL_HWXCREATE) GetProcAddress(hInstDll,TEXT("HwxCreate"));
        HWXSETGUIDE = (DLL_HWXSETGUIDE) GetProcAddress(hInstDll,TEXT("HwxSetGuide"));    
        HWXALCVALID = (DLL_HWXALCVALID) GetProcAddress(hInstDll,TEXT("HwxALCValid"));    
        HWXALCPRIORITY = (DLL_HWXALCPRIORITY) GetProcAddress(hInstDll,TEXT("HwxALCPriority"));
        HWXSETCONTEXT = (DLL_HWXSETCONTEXT) GetProcAddress(hInstDll,TEXT("HwxSetContext"));
        HWXINPUT = (DLL_HWXINPUT) GetProcAddress(hInstDll,TEXT("HwxInput"));
        HWXPROCESS = (DLL_HWXPROCESS) GetProcAddress(hInstDll,TEXT("HwxProcess"));
        HWXRESULTSAVAILABLE = (DLL_HWXRESULTSAVAILABLE) GetProcAddress(hInstDll,TEXT("HwxResultsAvailable"));
        HWXGETRESULTS = (DLL_HWXGETRESULTS) GetProcAddress(hInstDll,TEXT("HwxGetResults"));
        HWXDESTROY = (DLL_HWXDESTROY) GetProcAddress(hInstDll,TEXT("HwxDestroy"));
        HWXENDINPUT = (DLL_HWXENDINPUT) GetProcAddress(hInstDll,TEXT("HwxEndInput"));
    }
    else
    ...{
        return FALSE;
    }
#endif //RECOGNIZE_FUNCTION_FROM_DLL

    if(HWXCONFIG() == FALSE)
    ...{
        return FALSE;
    }

    return TRUE;
}


// -----------------------------------------------------------------------
// Descriptiong:
//     Begin recognizing
// -----------------------------------------------------------------------
BOOL CRecognizer::BeginRecognize()
... {
    BOOL bRes = FALSE;

    m_hrc = HWXCREATE();
    if(m_hrc == NULL)
    ...{
        goto END;
    }

    bRes = HWXSETGUIDE(m_hrc,&m_hwxGuide);
    if(bRes == FALSE)
    ...{
        goto END;
    }
    
    bRes = HWXALCVALID(m_hrc,m_alc);
    if(bRes == FALSE)
    ...{
        goto END;
    }

    bRes = TRUE;

END:
    return bRes;
}


// -----------------------------------------------------------------------
// Descriptiong:
//     End recognizing
// -----------------------------------------------------------------------
BOOL CRecognizer::EndRecognize()
... {
    BOOL bRes = FALSE;

    //Destroy the recognizer
    if(HWXDESTROY(m_hrc) == FALSE)
    ...{
        goto END;
    }

    bRes = TRUE;

END:
    return bRes;
}


// -----------------------------------------------------------------------
// Descriptiong:
//     Get the character
//
// Parameters:
//     pWchar: [out] The character get to be stored
//     iCount: [in] The number of pWchar 
//
// Return Values:
//     0:  Failed
//     >0: The number of the characters to return
// -----------------------------------------------------------------------
int  CRecognizer::GetCharacter(WCHAR  * pWchar,  int  iCount)
... {
    int iGetNum = 0;
    int i = 0;
    HWXRESULTS *phwxResults;
    //Because each HWXRESULTS after the first one could store two characters,
    //so only allocate (iCount / 2 + 1)
    int iNum = iCount / 2 + 1;
    phwxResults = new HWXRESULTS[iNum];
    memset(phwxResults,0,iNum * sizeof(HWXRESULTS));

    //End the input
    if(HWXENDINPUT(m_hrc) == FALSE)
    ...{
        goto END;
    }

    //Analyze the information 
    if(HWXPROCESS(m_hrc) == FALSE)
    ...{
        goto END;
    }



    //Get the character from recognizer
    if(HWXGETRESULTS(m_hrc,iCount,0,1,phwxResults) == FALSE)
    ...{
        goto END;
    }

    //Set the character to the stored buffer
    for(i = 0; i < iNum; i++)
    ...{
        if(i == 0)
        ...{
            if(phwxResults[i].rgChar[0] != 0)
            ...{
                pWchar[iGetNum ++] = phwxResults[i].rgChar[0];
            }
            else
            ...{
                break;
            }
        }
        else
        ...{
            //The indxBox member also store the character
            if(phwxResults[i].indxBox  != 0)
            ...{
                pWchar[iGetNum ++] = phwxResults[i].indxBox ;
            }
            else
            ...{
                break;
            }

            if(phwxResults[i].rgChar[0] != 0)
            ...{
                pWchar[iGetNum ++] = phwxResults[i].rgChar[0];
            }
            else
            ...{
                break;
            }

        }
    }

END:
    if(phwxResults != NULL)
    ...{
        delete [] phwxResults;
    }
    return iGetNum;
}


// -----------------------------------------------------------------------
// Descriptiong:
//     Input the stroke
//
// Parameter:
//     lpPnt: [in] Pointer to the stroke POINT
//     iCount: [in] The count of the lpPnt
//     scale: [in] The scale base of lpPnt
// -----------------------------------------------------------------------
BOOL CRecognizer::InputStroke(POINT  * lpPnt,  int  iCount, ScaleType scale)
... {
    BOOL bRes = FALSE;
    int i = 0;

    POINT *pt;
    pt = new POINT[iCount];
    if(pt == NULL)
    ...{
        goto END;
    }
    
    for(i = 0; i < iCount; i++)
    ...{
        pt[i] = lpPnt[i];
        
        if(scale == SCALE_APPWND)
        ...{
            //Convert to the screen scale
            pt[i].x *= 4;
            pt[i].y *= 4;
            MapWindowPoints(m_hWndRecog, HWND_DESKTOP, &pt[i], 1);
        }
    }

    //Input stroke
    bRes = HWXINPUT(m_hrc,pt,iCount,0);

    if(bRes == FALSE)
    ...{
        goto END;
    }

    bRes = TRUE;

END:
    if(pt != NULL)
    ...{
        delete [] pt;
    }
    return bRes;
}

  不知道大家看到这段代码有什么感觉,反正我是挺高兴的,因为让我从繁琐的识别过程中脱离出来.
  
  关于代码,也许最让人疑惑的可能是这两个宏:RECOGNIZE_FUNCTION_FROM_DLL,RECOGNIZE_FUNCTION_FROM_LIB.
  
  顾名思义,RECOGNIZE_FUNCTION_FROM_DLL表明识别函数调用是来源于动态链接库(DLL),同理,RECOGNIZE_FUNCTION_FROM_LIB则是编译的时候链接到lib库.为什么需要定义这两个宏呢?因为在标准的SDK下,如果直接包含"recog.h"后调用相关识别函数,是会报link错误.因为标准的SDK是不包含任何手写识别组件的.从调试的便利性来说,这时候如果只拷贝识别库到模拟器就可以顺利测试程序,绝对比重新定制一个包含手写识别引擎的系统要来得方便.
  
  在示例代码中,因为是识别繁体中文,所以包含的动态链接库为:hwxcht.dll.如果需要识别其它文字,则只要更改该动态链接库名称即可.当然,还要更改DEFAULT_ALC宏,这个宏定义了识别的范围.
  
  因为示例代码中的识别函数全部是宏定义,具体意义根据函数的来源而不同,所以RECOGNIZE_FUNCTION_FROM_DLL和RECOGNIZE_FUNCTION_FROM_LIB同一时间只能定义一个.如果两个都定义,毫无疑问,出错!^_^
  
  最后,用伪代码做范例说明如何使用该封装类,以此做本章结尾:

        CRecognizer recog;
        
        Rect rcWnd;        
         /**/ /*rcWnd 获取应用窗口hWnd的大小*/  
        
         // 初始化
         // 直接赋值窗口坐标,函数体内部会根据标志直接转换为屏幕坐标
        recog.Initialize(hWnd, & rcWnd,SCALE_APPWND); 
        
         // 开始识别
        recog.BeginRecognize();
        
        POINT pt[ 200 ];
         int  iCount  =   0 ;
         /**/ /*获取笔画坐标给pt,坐标的数量储存在iCount中*/
        
         // 将笔画点阵传送给识别引擎
         // 如果有多个笔画,则每个笔画都需要调用该函数进行传入
        recog.InputStroke(pt,iCount,SCALE_APPWND);
        
         // 获取十个最接近的字符,iReturn是实际返回的字符数
        WCHAR wChar[ 10 ];
         int  iReturn  =  recog.GetCharacter(wChar, 10 );
        
         // 结束识别
        recog.EndRecognize();
        
         /**/ /*如果