AutoCAD ObjectARX和RealDWG的基本数据操作

.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(""); //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(""); //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 have
102         case kEmbeddedImageFile:       // various extensions
103         default:
104             pExtension[0] = _T('');
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     else
114         return Acad::eFileNotFound;
115 }
116 Adesk::Boolean 
117 DumpDwgHostApp::isURL(const TCHAR* pszURL) const
118 {
119     return PathIsURL(pszURL);
120 }
121 
122 Adesk::Boolean 
123 DumpDwgHostApp::isRemoteFile(const TCHAR* pszLocalFile, TCHAR* pszURL, size_t nUrlSize) const
124 {
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) const
136 {
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 succeed
143         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
"), 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
"), L"E:\yu\Drawi11ng1.dwg");
 45         _tprintf(_T("File must have .dwg or .dxf extension
"));
 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 
"));
 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
 endX %lf,endY %lf,endZ %lf
",(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：

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原文地址：https://www.cnblogs.com/lowdys/p/3230183.html