AutoCAD DevBlog

Force AutoCAD to update the graphics display area

By Augusto Goncalves

You can force the graphics update inserting the following lines in the code:

actrTransactionManager->flushGraphics();

acedUpdateDisplay();

In the case where you use transactions to open entities and you have transaction(s) started, you then need to also call:

actrTransactionManager->queueForGraphicsFlush();

before calling the preceding functions.

Get points from a region (solid or body) in ObjectARX

By Augusto Goncalves

Using BRrep (Bound Representation) this sample does this for AcDbRegion. It can be modified to work on AcDb3dSolid or AcDbBody.

// Make sure you uncomment the following

//      #define _BREP_SUPPORT_

// On your StdAfx.h header file

// This will enable BREP on the code

static void getPoints(

            AcDbObjectId id,

            AcGePoint3dArray &points )

{   

  AcBrBrep*pBrep = new AcBrBrep;

  pBrep->setSubentPath( AcDbFullSubentPath( id, kNullSubentId ));  

  AcBrBrepFaceTraverser brFaTrav; 

  for (brFaTrav.setBrep(*pBrep);!brFaTrav.done();brFaTrav.next()) 

  {       

    AcBrFaceLoopTraverser faLoTrav;      

    AcBrFace face;    

    brFaTrav.getFace(face);    

    for(faLoTrav.setFace(face);!faLoTrav.done();faLoTrav.next())

    {         

      AcBrLoopEdgeTraverser loEdTrav; 

      if(loEdTrav.setLoop(faLoTrav) == AcBr::eOk)

      {           

        for( ; !loEdTrav.done(); loEdTrav.next())

        {            

          AcBrEdge edge;   

          loEdTrav.getEdge(edge);

          AcBrVertex start;     

          edge.getVertex1( start );  

          AcGePoint3d pt;           

          start.getPoint( pt );    

          points.append( pt );       

        }          

      } // else its an isolated loop    

    }   

  }

  delete pBrep;

}

 

static void AdskPointsFromRegion_GetPoints(void)

{

  ads_name eName;  

  ads_point pt;  

  if( RTNORM != acedEntSel(

    _T("\nPlease select a region "),

    eName, pt ) )

    return;

  AcDbObjectId id;

  acdbGetObjectId( id, eName ); 

  AcDbRegion*pRegion;   

  acdbOpenObject(pRegion, id, AcDb::kForRead );

  if( pRegion == NULL )   

    return; 

  AcGePoint3dArray points; 

  pRegion->close(); 

  getPoints( id, points );

  int nPoints = points.length();

  for( int i=0; i<nPoints; i++ )

  {

    acedGrDraw(

      asDblArray(points[i]),

      asDblArray(points[(i+1)%nPoints]), 1,0 );

  }

}

Get the Rotation Angle and Axis from AcGeMatrix3d

By Augusto Goncalves

The AcGeMatrix3d::rotation method returns a new matrix with the specified rotation angle, but how can we extract the angle from an existing matrix? The following code does this.

#define TWOPI 6.28318530718

void getAngleAndAxis(

           double& theta,

           AcGeVector3d& axis,

           const AcGeMatrix3d& m)

{

  // Contract:  The matrix `m' must NOT contain any scaling,

  // shearing or mirroring effects (i.e., m.det() must be 1.0).

  // See AcGeScale3d::removeScale( m ) to meet this contract

  // requirement. If axis is passed in such that it is non-zero,

  // then this method will attempt to orient the returned

  // axis in the same direction as the passed in axis,

  // i.e., the returned axis will be in the same half-space

  // as the original axis. (Note, the passed in axis will

  // be overwritten).

  //

  // Note that if the matrix has a mirror component,

  // ( ie the determinant = -1 ),  then its not possible to

  // construct a rotation that performs the transformation.

  // If you need convincing, then imagine how difficult it

  // would be rotate your left shoe, to be identical to your

  // right shoe ( its mirror image ).

 

  double trace, s;

  int i, j, k;

  double quat[4];

 

  assert(fabs(m.det() -1.0) <= AcGeContext::gTol.equalVector());

 

  trace = m(0, 0) + m(1, 1) + m(2, 2);

 

  if (trace > 0.0) {

    s = sqrt(trace + 1.0);

    quat[0] = s * 0.5;

    s = 0.5 / s;

    quat[1] = s * (m(2, 1) - m(1, 2));

    quat[2] = s * (m(0, 2) - m(2, 0));

    quat[3] = s * (m(1, 0) - m(0, 1));

 

  } else {

    i = 0;

    if (m(1, 1) > m(0, 0))

      i = 1;

    if (m(2, 2) > m(i, i))

      i = 2;

    j = (i + 1)%3;

    k = (i + 2)%3;

 

    s = sqrt(m(i, i) - (m(j, j) + m(k, k)) + 1.0);

    quat[i+1] = s * 0.5;

    s = 0.5 / s;

    quat[0] = s * (m(k, j) - m(j, k));

    quat[j+1] = s * (m(j, i) + m(i, j));

    quat[k+1] = s * (m(k, i) + m(i, k));

  }

 

  theta = 2.0 * acos(quat[0]);

  AcGeVector3d tempAxis;

 

  if (fabs(theta) >= AcGeContext::gTol.equalVector()) {

    double factor = 1.0 / sin(theta * 0.5);

    tempAxis.x = quat[1] * factor;

    tempAxis.y = quat[2] * factor;

    tempAxis.z = quat[3] * factor;

 

    // Flip direction and adjust angle if need be.

    //

    if (tempAxis.dotProduct(axis) < 0) {

      tempAxis *= -1;

      theta = TWOPI - theta;

    }

    axis = tempAxis;

  } else {

    theta = 0.0;

  }

}

Using acutPrintf in a Regular MFC DLL

By Augusto Goncalves

If you are using an MFC Regular DLL, you have to manage module state switching when calling acutPrintf(). You need to do something like this:

void arx_func() {

  // Put AFX_MANAGE_STATE in its own scope

  {

    AFX_MANAGE_STATE(AfxGetAppModuleState());

    acutPrintf(L"\nHi!");

  } // End of scope

 

  // More of your code

}

Integrating AutoCAD with Twitter using RESTSharp – Part 2

By Stephen Preston

In Part 1, I started learning RESTSharp via the Twitter search API – an API that doesn’t require authentication to use. My goal for this ‘Part 2’ post is to test basic OAuth using RESTSharp - specifically “Out Of Band’ (OOB) authentication. You’ll recall that OOB is where we launch the user’s default browser for them to authorize our app, and they are then given a PIN that they must type into the app they want to authorize – in this case our AutoCAD plug-in.

The advantage (or disadvantage, depending how you look at it) of blogging as you learn – rather than finishing a project and going back to document it afterwards – is that you never know how hard (or how easy) something will turn out to be. I was lucky that when I searched for a RESTSharp OAuth example, I almost immediately came across this test harness on the RESTSharp GitHub site that demonstrated how to use OAuth with Twitter.

Great – less work for me. But now you probably think I planned this because I’m lazy :-).

Here is the simple conversion of that code to work in AutoCAD – and note too that the GitHub version has a small bug in the final REST API call to account/verify_credentials – I assume the API has changed since that code was written. By the time we make that final call, the authorization process is complete and we have our authorization token – the call is to test that the OAuth process was successful.

using System;

using System.Net;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.EditorInput;

using RestSharp;

using RestSharp.Authenticators.OAuth;

using RestSharp.Contrib;

using RestSharp.Authenticators;

using System.Diagnostics;

 

namespace AcadTwitterTest1

{

  public class TwitterTestClass

  {

    [CommandMethod("OATEST")]

    public static void OAuthTest()

    {

      const string consumerKey = "YOUR KEY HERE";

      const string consumerSecret = "YOUR KEY HERE";

 

      var baseUrl = "http://api.twitter.com";

      var client = new RestClient(baseUrl);

      //Request token using our consumer and secret keys

      client.Authenticator =

        OAuth1Authenticator.ForRequestToken(consumerKey, consumerSecret);

      var request = new RestRequest("oauth/request_token", Method.POST);

      var response = client.Execute(request);

      var qs = HttpUtility.ParseQueryString(response.Content);

      var oauth_token = qs["oauth_token"];

      var oauth_token_secret = qs["oauth_token_secret"];

 

      //authorize using returned token

      request = new RestRequest("oauth/authorize");

      request.AddParameter("oauth_token", oauth_token);

      var url = client.BuildUri(request).ToString();

      //Launch default browser with authorization URL

      Process.Start(url);

      //User logs into Twitter and clicks 'authorize' button

      //Browser displays PIN

 

      Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;

      //Ask user to enter the PIN displayed in the browser

      PromptStringOptions opts =

        new PromptStringOptions("\nEnter Twitter authorization PIN:");

      opts.AllowSpaces = true;

      PromptResult res = ed.GetString(opts);

      if (res.Status != PromptStatus.OK)

        return;

      string strPIN = res.StringResult.Trim();

      if (strPIN == "")

        return;

 

      //Use PIN to request access token for users account

      request = new RestRequest("oauth/access_token", Method.POST);

      client.Authenticator = OAuth1Authenticator.ForAccessToken(

      consumerKey, consumerSecret, oauth_token, oauth_token_secret, strPIN

      );

      response = client.Execute(request);

      qs = HttpUtility.ParseQueryString(response.Content);

      oauth_token = qs["oauth_token"];

      oauth_token_secret = qs["oauth_token_secret"];

 

      //Test it worked by calling verify_credentials API

      //Note - the code listed on

      // https://github.com/restsharp/RestSharp/blob/master/RestSharp.IntegrationTests/oAuth1Tests.cs

      // contains a bug (maybe the API changed). The next line in

      // the original is

      // request = new RestRequest("account/verify_credentials.xml");

      // i.e. Its missing the 1.1.

      request = new RestRequest("1.1/account/verify_credentials.json");

      client.Authenticator = OAuth1Authenticator.ForProtectedResource(

      consumerKey, consumerSecret, oauth_token, oauth_token_secret

      );

      //Put a breakpoint on following line and check that

      // response.StatusCode == HttpStatusCode.OK.

      // And check the returned JSON string.

      response = client.Execute(request);

    }

  }

}

I’ve removed my Consumer Key and Consumer Secret Key from the code sample above. To create your own, you have to login to your Twitter account, and then create a new app at https://dev.twitter.com/apps. (See this link for details of the Twitter authentication process).

Set a breakpoint on the last line of code before you run it in the debugger.

Running the OATEST command in AutoCAD launches my default browser for me to login to Twitter and authorize the app (note that I’ve given my app the highest access level by editing the settings for my access keys):

When I’ve entered the username and password for the test account (that I set up specially for this test) and clicked the Authorize app button, Twitter gives me my PIN:

I type this PIN when prompted on the AutoCAD commandline, and hit the breakpoint I set at the end of my function. Stepping over that line and querying the ‘response’ variable in the debugger, I can see that the returned JSON string looks like this:

{

"id":1058645280,

"entities":

{

"description":

  {

  "urls":[]

  }

},

"profile_use_background_image":true,

"default_profile":true,

"statuses_count":0,

"profile_text_color":"333333",

"id_str":"1234567890",

"screen_name":"SGP2013",

"follow_request_sent":false,

"followers_count":2,

"profile_image_url_https":"https:\/\/twimg0-a.akamaihd.net\/sticky\/default_profile_images\/default_profile_0_normal.png",

"utc_offset":null,

"profile_sidebar_border_color":"C0DEED",

"name":"Stephen Preston",

"lang":"en",

"is_translator":false,

"listed_count":0,

"created_at":"Thu Jan 03 19:57:42 +0000 2013",

"protected":false,

"profile_background_tile":false,

"profile_sidebar_fill_color":"DDEEF6",

"url":null,"profile_image_url":"http:\/\/a0.twimg.com\/sticky\/default_profile_images\/default_profile_0_normal.png",

"following":false,

"default_profile_image":true,

"profile_background_color":"C0DEED",

"favourites_count":0,

"friends_count":4,

"contributors_enabled":false,

"location":null,

"time_zone":null,

"notifications":false,

"profile_background_image_url":"http:\/\/a0.twimg.com\/images\/themes\/theme1\/bg.png",

"verified":false,

"profile_link_color":"0084B4",

"description":null,

"profile_background_image_url_https":"https:\/\/twimg0-a.akamaihd.net\/images\/themes\/theme1\/bg.png",

"geo_enabled":false

}

In this post I’ve shown how to use OOB OAuth authentication. This is my preferred approach for an AutoCAD commandline app – and something I found wasn’t possible (yet) using the Evernote API. In my next post I’ll find something more interesting to do with the Twitter API now my OAuth is working.

CAdUiPaletteSet's keep turning into CAdUiDockControlBars when calling FloatControlBar

By Gopinath Taget

You might find that instances of CAdUiPaletteSet's keep turning into CAdUiDockControlBars when called with FloatControlBar method.

Applications normally manage the state of docking windows (CControlBars) using the standard MFC methods CFrameWnd::DockControlBar(), CFrameWnd::FloatControlBar() and CFrameWnd::ShowControlBar() (Docking windows should not be shown/hidden using calls to CWnd::ShowWindow()). 

Applications can continue to call CFrameWnd::DockControlBar() and CFrameWnd::ShowControlBar() normally. However, when calling CFrameWnd::FloatControlBar(), applications will need to "swap" the floating frame class if the control bar passed to FloatControlBar() is a kind of CAdUiPaletteSet. Applications can perform this "swap" by calling the new method AdUiSetFloatingFrameClass() before and after the call to FloatControlBar():

CRect mRect(100,100, 300, 600);
GetPaletteSet()->InitFloatingPosition(&mRect);

CMDIFrameWnd* pAcadFrame = acedGetAcadFrame();
CRuntimeClass* pCurrentFloatingFrameClass = AdUiSetFloatingFrameClass(RUNTIME_CLASS(CAdUiPaletteSetDockFrame));
acedGetAcadFrame()->FloatControlBar(GetPaletteSet(),CPoint(mRect.left, mRect.top),CBRS_ALIGN_TOP );
AdUiSetFloatingFrameClass(pCurrentFloatingFrameClass);

Why is all of this necessary? MFC's CFrameWnd class caches a pointer to the floating frame class used as a private member of the class. This class pointer is used to instantiate a floating frame for dock control bars when they are floating by CFrameWnd::FloatControlBar(). AdUi needs to continue to support for custom dialogs derived directly from CAdUiControlBar. So AdUi host applications need to use two different floating frame classes, one for those derived from CAdUiControlBar and another for those derived from CAdUiPaletteSet. 

Unfortunately FloatControlBar() is not a virtual method so it is not possible to override it in the application frame class to automatically detect the control bar class and use the correct floating frame. Instead applications must detect the control bar class themselves and manually swap the floating frame class before calling CFrameWnd::FloatControlBar().

Lock a document preventing others from modifying

By Gopinath Taget

If some system variables are valid on a per-document basis, such as CLAYER, and you are modifying a document, some other applications could try to modify it at the same time before your application ends. This could cause CLAYER variable's value to be unreliable for your application. How do you prevent this from happening?

Many system variables such as CLAYER are on a per-document basis. The situation as stated can occur; to avoid this, you'll need to lock the current document that you're working on before you try to modify a per-document system variable such as CLAYER. This way, depending on the lock mode you specify, undesirable modifications can be blocked.

The following code demonstrates how you can add a layer to the current document and set it to be the current layer while preventing other documents from modifying the database. Notice that some error handling code is omitted for code brevity.

// Note: you could place the lock on a broader scope depending on

// your actual needs.

void testLock()

{

Acad::ErrorStatus es;   

 // exclusive write so only you app can write to the document 

 // before you unlock the document 

es = acDocManager->lockDocument(curDoc(), AcAp::kXWrite, NULL,

  NULL,false); 

assert(es == Acad::eOk); 

AcDbDatabase* pDb = curDoc()->database();

AcDbLayerTable* pTable;

es = pDb->getLayerTable(pTable, AcDb::kForRead);  

 const ACHAR layName[] = L"testLayer";   

AcDbLayerTableRecord* pRecord; 

 if(pTable->has(layName))

{

  es = pTable->getAt(layName, pRecord, AcDb::kForRead);   

  assert(es == Acad::eOk);

}   

 else 

{ 

  pRecord = new AcDbLayerTableRecord;   

  pRecord->setName(layName);

  pTable->upgradeOpen();

  es = pTable->add(pRecord);    

  assert(es == Acad::eOk);

} 

AcDbObjectId id = pRecord->objectId();  

pTable->close();  

pRecord->close();

es = curDoc()->database()->setClayer(id); 

assert(es == Acad::eOk);   

es = acDocManager->unlockDocument(curDoc());  

assert(es == Acad::eOk);

}

Setting a plot style name

By Gopinath Taget

You might find that when trying to assign a plot style to a layer using AcDbLayerTableRecord::setPlotStyleName(), it returns "eKeyNotFound" sometimes?

This is because PlotStyles and plotStyleNames are not the same. PlotStyleNames are just entries in the plotStyleName Dictionary (ACAD_PLOTSTYLENAME). They do not rely on the plotStyles in the STB files, nor are they automatically generated by plotStyles. The intent is the opposite of what you might think; the plotStyleName is used as a lookup name when AutoCAD looks for a plotStyle.

When setPlotStyleName returns "Acad::eKeyNotFound", it is indicating that there is no such entry in the plotStyleName Dictionary. To create a desired entry in this dictionary, you can use the AcDbDatabase::getPlotStyleNameDictionary() method to get a pointer to the plotStyleName dictionary (it is an object of class AcDbDictionaryWithDefault type that is derived from AcDbDictionary). You then need to create a new AcDbPlaceHolder object and add it to the plotStyleName dictionary using your desired plotStyleName as the entry's key.

Notice that the plotStyleName dictionary has a default entry "Normal" of AcDbPlaceHolder class. And the setPlotStyleName function returns an error status if the plot style cannot be found in the current plot style table (as this case), or if the drawing's PlotStyleMode is set to use color-based plot styles.

The following code shows how to do this:

static void setNewPlotStyleName()

{   

AcDbDatabase* pDb = curDoc()->database();   

AcDbDictionaryWithDefault* pDict = NULL;   

 

  Acad::ErrorStatus es = pDb->getPlotStyleNameDictionary(pDict,

  AcDb::kForWrite);   

 if(es != Acad::eOk)       

  return;   

AcDbPlaceHolder* pNewHolder = new AcDbPlaceHolder;   

 if(!pNewHolder)   

{       

  pDict->close();       

  return;   

}   

AcDbObjectId newId;   

 const TCHAR newStyleName[] = _T("Sample plot style name");   

es = pDict->setAt(newStyleName, pNewHolder, newId);   

 if(es != Acad::eOk)   

{       

  delete pNewHolder;       

  pDict->close();       

  return;   

}   

 

 // close the new object   

pNewHolder->close();   

 // set the defaultId to be the new one   

 // you don't have to do this but this is to demonstrate   

 // that you can    

es = pDict->setDefaultId(newId);   

 if(es != Acad::eOk)   

{       

  // since it is already database resident       

  // we can only erase it       

  es = acdbOpenAcDbObject((AcDbObject *&)pNewHolder, newId,

   AcDb::kForWrite);       

  assert(es == Acad::eOk);       

  pNewHolder->erase();       

  pNewHolder->close();       

  pDict->close();       

  return;   

}   

pDict->close();   

 // open the current layer table record   

AcDbLayerTableRecordPointer pLayerBtr(pDb->clayer(),

  AcDb::kForWrite);   

es = pLayerBtr.openStatus();   

 if(es == Acad::eOk)   

{       

  // set its plot style name       

  es = pLayerBtr->setPlotStyleName(newStyleName);       

  if(es != Acad::eOk)           

   acutPrintf(_T("Error setting plot style name %s."),

   newStyleName);   

}

}

//// This should always work as long as

// someone has not altered the "Normal" name programmatically.

// Again this is for companion demonstration purpose.

//

static void setDefaultPlotStyleName()

{   

 const TCHAR styleName[] = _T("normal");   

AcDbDatabase* pDb = curDoc()->database();   

 // open the current layer table record   

AcDbLayerTableRecordPointer pLayerBtr(pDb->clayer(),

  AcDb::kForWrite);   

Acad::ErrorStatus es = pLayerBtr.openStatus();   

 if(es == Acad::eOk)   

{       

  // set its plot style name       

  es = pLayerBtr->setPlotStyleName(styleName);       

  if(es != Acad::eOk)           

   acutPrintf(_T("Error setting plot style name %s."),

   styleName);   

}

}

Making non-database resident objects work with undo

By Gopinath Taget

Non-database resident objects do not participate in an Undo/Redo. However, it is fairly easy to take advantage of the built-in Undo/Redo feature with the following procedure:

1. Derive your objects from AcDbObject as if you were creating a custom database-resident object. (You will only need to override the dwgInFields/dwgOutFields methods.)
2. Append the objects to the database using AcDbDatabase::addAcDbObject

The addAcDbObject function appends the object to the database but does not set up an owner for the object so it will not be saved when the database is saved.

You will need to use proper open/close protocol on this object to ensure undo/redo works as expected.

Reliable Identifier/GUID for a P&ID Project

By Fenton Webb

If you are looking for a unique P&ID project GUID, as of 2013 Plant3d the PnPDatabase.DbId() is the best way to go.

Note: that if you copy the whole project to a new location this GUID will *not* change.