.dwg文件的读取。拥有RealDWG或者ObjectARX不必多说。

安装RealDWG后RealDWG目录下的Samples看看。

新建工程配置好Inc,Lib，附加依赖等。

不必多说。

需要将AcDbHostApplicationServices实现一遍。

sample自带的即可，也可自己按照自己的来写。

1 int Verbose = 0;  2 int Copy = 0;  3 int Header = 0;  4 int Tables = 0;  5 int doExtents = 0;  6 int showErased = 0;  7 int resolveXrefs = 0;  8   9 class DumpDwgHostApp : public AcDbHostApplicationServices 10 { 11 public: 12     ~DumpDwgHostApp(); 13     Acad::ErrorStatus findFile(TCHAR* pcFullPathOut, int nBufferLength, 14                          const TCHAR* pcFilename, AcDbDatabase* pDb = NULL, 15                          AcDbHostApplicationServices::FindFileHint = kDefault); 16     // These two functions return the full path to the root folder where roamable/local  17     // customizable files were installed. Note that the user may have reconfigured  18     // the location of some the customizable files using the Options Dialog  19     // therefore these functions should not be used to locate customizable files.  20     // To locate customizable files either use the findFile function or the  21     // appropriate system variable for the given file type.  22     // 23     Acad::ErrorStatus getRoamableRootFolder(const TCHAR*& folder); 24     Acad::ErrorStatus getLocalRootFolder(const TCHAR*& folder); 25  26     //URL related services 27     Adesk::Boolean isURL(const TCHAR* pszURL) const; 28     Adesk::Boolean isRemoteFile(const TCHAR* pszLocalFile, TCHAR* pszURL, size_t nUrlSize) const; 29     Acad::ErrorStatus  getRemoteFile(const TCHAR* pszURL, TCHAR* pszLocalFile, size_t nFilePath, Adesk::Boolean bIgnoreCache) const; 30  31     // make sure you implement getAlternateFontName. In case your findFile implementation 32     // fails to find a font you should return a font name here that is guaranteed to exist. 33     virtual TCHAR * getAlternateFontName() const 34     { 35         return _T("txt.shx"); //findFile will be called again with this name 36     } 37 private: 38     mutable CMapStringToString m_localToUrl; 39 }; 40 DumpDwgHostApp::~DumpDwgHostApp() 41 { 42     CString local,url; 43     for (POSITION pos = m_localToUrl.GetStartPosition();pos!=NULL;) 44     { 45         m_localToUrl.GetNextAssoc(pos,local,url); 46         DeleteUrlCacheEntry(url); 47     } 48 } 49 // Return the Install directory for customizable files 50 Acad::ErrorStatus  51 DumpDwgHostApp::getRoamableRootFolder(const TCHAR*& folder) 52 { 53     Acad::ErrorStatus ret = Acad::eOk; 54     static TCHAR buf[MAX_PATH] = _T("\0"); //MDI SAFE 55     if (buf[0]==0) 56         if (GetModuleFileName(NULL, buf, MAX_PATH) != 0) 57             ret = Acad::eRegistryAccessError; 58     folder = buf; 59     return ret; 60 } 61  62 // Return the Install directory for customizable files 63 Acad::ErrorStatus  64 DumpDwgHostApp::getLocalRootFolder(const TCHAR*& folder) 65 { 66     Acad::ErrorStatus ret = Acad::eOk; 67     static TCHAR buf[MAX_PATH] = _T("\0"); //MDI SAFE 68     if (buf[0]==0) 69         if (GetModuleFileName(NULL, buf, MAX_PATH) != 0) 70             ret = Acad::eRegistryAccessError; 71     folder = buf; 72     return ret; 73 } 74  75 Acad::ErrorStatus  76 DumpDwgHostApp::findFile(TCHAR* pcFullPathOut, int nBufferLength, 77     const TCHAR* pcFilename, AcDbDatabase* pDb,  78     AcDbHostApplicationServices::FindFileHint hint) 79 { 80     TCHAR pExtension[5]; 81     switch (hint) 82     { 83         case kCompiledShapeFile: 84             _tcscpy(pExtension, _T(".shx")); 85             break; 86         case kTrueTypeFontFile: 87             _tcscpy(pExtension, _T(".ttf")); 88             break; 89         case kPatternFile: 90             _tcscpy(pExtension, _T(".pat")); 91             break; 92         case kARXApplication: 93             _tcscpy(pExtension, _T(".dbx")); 94             break; 95         case kFontMapFile: 96             _tcscpy(pExtension, _T(".fmp")); 97             break; 98         case kXRefDrawing: 99             _tcscpy(pExtension, _T(".dwg"));100             break;101         case kFontFile:                // Fall through.  These could have102         case kEmbeddedImageFile:       // various extensions103         default:104             pExtension[0] = _T('\0');105             break;106     }107     TCHAR* filePart;108     DWORD result;109     result = SearchPath(NULL, pcFilename, pExtension, nBufferLength, 110                         pcFullPathOut, &filePart);111     if (result && result < (DWORD)nBufferLength)112         return Acad::eOk;113     else114         return Acad::eFileNotFound;115 }116 Adesk::Boolean 117 DumpDwgHostApp::isURL(const TCHAR* pszURL) const118 {119     return PathIsURL(pszURL);120 }121 122 Adesk::Boolean 123 DumpDwgHostApp::isRemoteFile(const TCHAR* pszLocalFile, TCHAR* pszURL, size_t nUrlSize) const124 {125     CString value;126     if (m_localToUrl.Lookup(pszLocalFile,value))127     {128         _tcscpy_s(pszURL, nUrlSize, value);129         return TRUE;130     }131     return FALSE;132 }133 134 Acad::ErrorStatus  135 DumpDwgHostApp::getRemoteFile(const TCHAR* pszURL, TCHAR* pszLocalFile, size_t nFilePath, Adesk::Boolean bIgnoreCache) const136 {137     DWORD err = ERROR_FILE_NOT_FOUND;138     if (!bIgnoreCache)139     {140         DWORD size = 0;141         if (GetUrlCacheEntryInfo(pszURL,NULL,&size))142             return Acad::eInetFileGenericError; //this shouldn't succeed143         err = GetLastError();144         if (err == ERROR_INSUFFICIENT_BUFFER)145         {146             INTERNET_CACHE_ENTRY_INFO* pCacheEntry = (INTERNET_CACHE_ENTRY_INFO*)malloc(size);147             if (GetUrlCacheEntryInfo(pszURL,pCacheEntry,&size))148             {149                 _tcscpy_s(pszLocalFile, nFilePath, pCacheEntry->lpszLocalFileName);150                 m_localToUrl.SetAt(pszLocalFile,pszURL);151                 free(pCacheEntry);152                 return Acad::eInetOk;153             }154             err = GetLastError();155         }156     }157     if (err == ERROR_FILE_NOT_FOUND)158     {159         if (SUCCEEDED(URLDownloadToCacheFile(NULL,pszURL,pszLocalFile,_MAX_PATH,0,NULL)))160         {161             m_localToUrl.SetAt(pszLocalFile,pszURL);162             return Acad::eInetOk;163         }164     }165     return Acad::eInetFileGenericError;166 }

到此进入正题：

1 void createScene()  2     {  3                acdbSetHostApplicationServices(&gDumpDwgHostApp);  4         long lcid = 0x00000409;  // English  5         acdbValidateSetup(lcid);  6   7         acrxLoadModule(acIsmObjDbxFile, 0);  8   9         Ogre::Entity* ent = mSceneMgr->createEntity("myentity", "person.mesh"); 10         //ent-> 11          12         Ogre::SceneNode* node1 = mSceneMgr->createSceneNode("node1"); 13         node1->setPosition(1177, 702, 0); 14         mSceneMgr->getRootSceneNode()->addChild(node1); 15         node1->attachObject(ent); 16         node1->setScale(0.1,0.1,0.1); 17   18         Ogre::Entity* ent2 = mSceneMgr->createEntity("myentity2", "Sinbad.mesh"); 19         Ogre::SceneNode* node2 = mSceneMgr->createSceneNode("node2"); 20         node2->setPosition(1410, 900, 10); 21         node1->addChild(node2); 22         node2->attachObject(ent2); 23  24  25         ManualObject* manual = mSceneMgr->createManualObject("manual"); 26         manual->begin("BaseWhiteNoLighting", RenderOperation::OT_LINE_LIST); 27  28  29         AcDbDatabase *pDb = new AcDbDatabase(Adesk::kFalse); 30     if (pDb == NULL) 31         return; 32  33     //_tprintf(_T("%s\n"), L"E:\\yu\\Drawi11ng1.dwg"); 34  35     TCHAR drive[_MAX_DRIVE] = _T(""); 36     TCHAR dir[_MAX_DIR] = _T(""); 37     TCHAR fname[_MAX_FNAME] = _T(""); 38     TCHAR ext[_MAX_EXT] = _T(""); 39  40     _tsplitpath_s(L"E:\\yu\\Drawi11ng1.dwg", drive, dir, fname, ext); 41  42     if (_tcsicmp(ext, _T(".dwg")) && _tcscmp(ext, _T(".dxf"))) 43     { 44         _tprintf(_T("Can't open %s\n"), L"E:\\yu\\Drawi11ng1.dwg"); 45         _tprintf(_T("File must have .dwg or .dxf extension\n")); 46         delete pDb; 47         return; 48     } 49  50     if(pDb->readDwgFile(L"E:\\yu\\Drawi11ng1.dwg") == Acad::eOk) 51     { 52         acdbHostApplicationServices()->setWorkingDatabase(pDb); 53         int ntet = 1; 54     } 55  56     AcDbLayerTable* pLayerTbl; 57         pDb->getSymbolTable(pLayerTbl,AcDb::kForRead); 58  59         if(!pLayerTbl->has(L"568中段")) 60         { 61             _tprintf(_T("Don't have 568中段 \n")); 62             pLayerTbl->close(); 63             return; 64         } 65  66         AcDbObjectId layerId;  //568中段 图层id 67         pLayerTbl->getAt(L"568中段",layerId); 68         pLayerTbl->close(); 69  70         //get blocktbl 71         AcDbBlockTable* pBlockTbl; 72         pDb->getSymbolTable(pBlockTbl,AcDb::kForRead); 73  74         AcDbBlockTableRecord *pBlockTableRecord;  75         pBlockTbl->getAt(ACDB_MODEL_SPACE, pBlockTableRecord, AcDb::kForRead); 76         pBlockTbl->close(); 77  78         //create AcDbBlockTableIterator 79         AcDbBlockTableRecordIterator* thlIter; 80         pBlockTableRecord->newIterator(thlIter); 81         AcDbEntity* pEnt;    // 82         for(thlIter->start();!thlIter->done();thlIter->step()) 83         { 84             //利用遍历器获得每一个实体 85             thlIter->getEntity(pEnt,AcDb::kForWrite); 86             if(pEnt->layerId() == layerId) 87             { 88                 //is line 89                 AcDbLine* pLine = AcDbLine::cast(pEnt); 90                 if(pLine != NULL) 91                 { 92                     //pLine   93                     AcGePoint3d startP(0,0,0),endP(0,0,0); 94                     startP = pLine->startPoint(); 95                     endP = pLine->endPoint(); 96                     printf("yu %s startX %lf,startY %lf,startZ %lf\n endX %lf,endY %lf,endZ %lf\n",(pEnt->isA())->name(),startP.x,startP.y,startP.z,endP.x,endP.y,endP.z); 97                     manual->position(startP.x, startP.y, startP.z);  // start position 98                     manual->position( endP.x,endP.y, endP.z);  // draw first line 99                 }100             }101 102             pEnt->close();103         }104         delete thlIter;105         pBlockTableRecord->close();106 107         manual->end();108 109         mSceneMgr->getRootSceneNode()->createChildSceneNode()->attachObject(manual);110  111 //      mSceneMgr->getRootSceneNode()->attachObject(ent);112     }113  114 private:115  116 };

这里有些无关紧要的代码，大家不要介意。看重点即可，新建一个数据库对象 AcDbDatabase *pDb = new AcDbDatabase(Adesk::kFalse);

打开一个DWG文件 pDb->readDwgFile(L"E:\\yu\\Drawi11ng1.dwg") == Acad::eOk，当然可以打开指定的文件，也有打开多个DWG的，这里就不细说；打开模型空间块表记录，遍历模型空间块表记录，找到符合自己要求的数据，读取即可。

cad图：

读取后显示效果图：

到此，打开dwg文件，读取指定数据，用OGRE显示均正常，结束。

插入cj小美女镇楼：