AutoCAD DevBlog

Obtain the RGB color value from an AcDbEntity using ObjectARX and RealDWG

by Fenton Webb

Here’s how to obtain the RGB value from an already AcDb::kOpenForRead AcDbEntity.

static COLORREF GetRGBFromEntity( AcDbEntity *ent )

{

  COLORREF colorRef = RGB(255, 255, 255);

  AcCmColor Color = ent->color();

  AcCmEntityColor::ColorMethod ColorMethod = Color.colorMethod();

 

  switch(ColorMethod)

  {

  case AcCmEntityColor::kByACI:

    {         

      long acirgb, r,g,b;

      acirgb = AcCmEntityColor::lookUpRGB(Color.colorIndex());

 

      b = ( acirgb & 0xff00L );

      g = ( acirgb & 0xff00L ) >> 8;

      r = acirgb >> 16;

 

      colorRef = RGB( r, g, b); 

      break;

 

    }

  }

  return colorRef;

}

 

Change the background mask property of AcDbMText object programmatically using ObjectARX

by Fenton Webb

Issue

I need to create (or set) an AcDbMText object with the background mask turned on. How can I do so programmatically?

Solution

We can do this both in ObjectARX and LISP.

In ObjectARX, we can use setBackgroundFill() member function of class AcDbMText to do the job. Please find the following code which toggles the background mask property of an MText entity.

void test_setBackgroundFill_MText()

{

  ads_name ename;

  ads_point p;

  // select the entity

  int res = acedEntSel(_T("Please pick an MText entity: "), ename, p );

  // if ok

  if (res == RTNORM)

  {

    AcDbObjectId oId;

    acdbGetObjectId( oId, ename );

    AcDbObjectPointer<AcDbMText> pMText(oId, AcDb::kForWrite);

 

    if(pMText.openStatus() == Acad::eOk)

    {

      AcCmColor color;

      if(pMText->backgroundFillOn())

      {

        pMText->setUseBackgroundColor(false);

        pMText->setBackgroundFill(false);

      }

      else

      {

        pMText->setBackgroundFill(true);

        color.setColorIndex(1);

        pMText->setBackgroundFillColor(color);

        pMText->setUseBackgroundColor(false);

      }

    }

    else

      acutPrintf(_T("\nError - you need to select an MText entity..."));

  }

}

 

In LISP, we can add group code 90 and set it as 1 to turn on the background mask. If we want to use a different color than the one used last time we can add group code 63 such as (63 . 1) - RED color - as well. We can turn off the mask by removing group code 90 and all related ones such as 63, 45, 441 and 421 (if applicable). A small tip here, we can substitute the original sub list of group code 90 with (90 . 2) to turn the mask off successfully and do not need to care about other related group codes. The following LISP code demonstrates how to do so…

 

(defun toggleBackgroundMaskOfAMText (en / ed)
  (setq ed (entget en))   ; Sets ed to the entity data
  (setq atom90 (assoc 90 ed))
  (if (= atom90 nil)
    ;; no 90 groud code at all
    (progn
      (setq lst90 (cons 90 1))
      (setq atom63 (cons 63 1))
      (setq ed (append ed (list atom63 lst90)))
      ;; Add the 63 group code to set the background color as 1 (RED)
    )
    (progn
      (setq maskProp (cdr atom90))
      (if (= (boole 1 maskProp 1) 1)
(setq new90 (cons 90 2))
(setq new90 (cons 90 1))
      )
      (setq ed
      (subst new90
      (assoc 90 ed) ; Toggle the value of 90 group in ed.
      ed
      )
      )
    )
  )

  (entmod ed)
  (princ)
)

(defun c:testBGMask ()
  (toggleBackgroundMaskOfAMText
    (car (entsel))
  )
)

 

Here is some information about the DXF group codes related to Background Mask of MTEXT entities.

** Group code 90: Bit flags for background Mask

The possible values can be:

        kFillTextBox            = 0x1
        kFillTextBoxBackground  = 0x2
        kUseWordBreak           = 0x4
        kCheckedForUseWordBreak = 0x8

In the Background Mask dialog UI (while in the text editor or double click on the text --> right click context menu -->  [Background Mask..]), we can check the 'Use background mask' option to set the kFillTextBox bit and 'Use drawing background color' option in the 'Fill Color' group to set the kFillTextBoxBackground bit. In ARX API, We can use AcDbMText::backgroundFillOn() AcDbMText::setBackgroundFill() to get and set the kFillTextBoxBackground bit.

** Group code 63:  Fill Color

Specifies the color for the background. If it is a true color, Group code 63 gives the ACI color value and the corresponding Group code 421 gives the AcCmColor’s value.

We can specify the background color of the MTEXT in the Background Mask dialog UI. In ARX API, we can use AcDbMText::getBackgroundFillColor and AcDbMText::setBackgroundFillColor to get and read the value.

** Group code 45:  Border Offset Factor

Specifies the margin around the text for the opaque background. The value is based on the text height. A factor of 1.0 exactly fits the multiline text object. A factor of 1.5 extends the background by 0.5 times the text height.

In the Background Mask dialog UI, we can specify it in the 'Border offset factor' field. In ARX API, We can use AcDbMText::getBackgroundScaleFactor and AcDbMText::setBackgroundScaleFactor to get and set the value.

** Group code 441: Transparency color. 

The corresponding data member is of AcCmTransparency Type. This can not be controlled by the Background Mask dialog UI. But we can get or set this value using AcDbMText::getBackgroundTransparency and AcDbMText::setBackgroundTransparency methods.

Setting your AutoCAD OEM Default Graphics window Color

by Fenton Webb

You might need to set the AutoCAD Drawing Window color (Model Space Background) to a different color via your installer. To do so is pretty easy – simply set your OEM registry key .\Profiles\<<Unnamed Profile>>\Drawing Window\Background setting to the desired DWORD value.

Some Tips on AutoCAD OEM

by Fenton Webb

Just some small for new users of AutoCAD OEM…

1) When you install OEM on your system, you install two things - the Toolkit (OemMakeWizard and OemInstallerWizard) and a runnable application called AutoCAD OEM.

2) AutoCAD OEM is a relaxed version of any OEM product you build with the OemMakeWizard. It is used to test OEM specific stuff you are doing, it allows NETLOAD, Appload and the VBAIDE (if VBA is installed)...

3) The modules you add to OEM are usually just your modules and direct dependencies – basically the ones that you load into normal AutoCAD, and the ones that your App relies on (excluding standard runtime modules).

4) DLLs that you include *must* be built with the OEM ObjectARX SDK because OEM modules are dependent on aoem.exe not acad.exe like in the normal ObejctARX SDK. If you try to load modules built with the normal ObjectARX SDK they will not load because they are being physically loaded into the wrong host exe.

5) When you rebuild your app DLLs, you must rebuild your OEM product in order to test them - basically, your application DLLs must be restamped and aligned with your OEM product.

6) In order for your application to load properly, you must have a unique Logical Name in Your Modules declaration page of the OemMakeWizard.

Silent install of AutoCAD OEM

by Fenton Webb

If you are trying to silently install your AutoCAD OEM maybe because it’s a prerequisite of another installer, then here’s how to do it…

setup.exe /t /q /c AOEM: INSTALLDIR="C:\Program Files\MyApp" InstallLevel=5 

In fact, that line can also be used to install any Autodesk product silently… Just substitute AOEM for the main section in the setup.ini file… e.g. AutoCAD=ACAD

Delete layer filters using ObjectARX

by Fenton Webb

Issue

I have a customer who uses many dwgs with many filters on the layer. How can I delete the filters using a program?

Solution

Layer filters exist as AcDbXRecord entries in two dictionaries (with name "ACAD_LAYERFILTERS" and "ACLYDICTIONARY") contained in the extension dictionary of Layer Table. To delete the layer filters, you need to iterate through the "ACAD_LAYERFILTERS" and "ACLYDICTIONARY" dictionaries and delete all AcDbXRecords.

The code below opens a dummy drawing and deletes all layer filters inside of the drawing:

static void ASDKLayerFilterDelete_DeleteLayerFilters(void)

{

  // Set constructor parameter to kFalse so that the

  // database will be constructed empty.  This way only

  // what is read in will be in the database.

  AcDbDatabase *pDb = new AcDbDatabase(Adesk::kFalse);

 

  // The AcDbDatabase::readDwgFile() function

  // automatically appends a DWG extension if it is not

  // specified in the filename parameter.

  pDb->readDwgFile(_T("c:\\drawing1.dwg"));

  // ensure the whole dwg is read

  pDb->closeInput(true);

 

  // Get the Layer Table

  AcDbLayerTablePointer pLyrTbl(pDb->layerTableId(), AcDb::kForRead);

  if (pLyrTbl.openStatus() == Acad::eOk)

  {

    // Get Extention dictionary

    AcDbObjectId pExtDicId = pLyrTbl->extensionDictionary();

 

    if(pExtDicId.isValid())

    {        

      AcDbDictionaryPointer pDict(pExtDicId,AcDb::kForRead);

      if(Acad::eOk == pDict.openStatus())

      {

        // Get Layer Filter Dictionary from extension dictionary

        AcDbObjectId pObjId;

        pDict->getAt(_T("ACAD_LAYERFILTERS"),pObjId);

 

        if(pObjId.isValid())

        {

          AcDbDictionaryPointer pFiltDict(pObjId,AcDb::kForRead);

 

          if(Acad::eOk == pFiltDict.openStatus())

          {

            // Get objects in layer filter dictionary

            AcDbObjectId filtObjId;

            AcDbDictionaryIterator *pItr = pFiltDict->newIterator();

            if (NULL != pItr)

            {

              for(;!pItr->done();pItr->next())

              {

                AcDbObjectPointer<AcDbXrecord> pLyrFltr(pItr->objectId(),AcDb::kForWrite);

                if(Acad::eOk == pLyrFltr.openStatus())

                {

                  pLyrFltr->erase();

                }

              }

              delete pItr;

            }

          }

        }    

 

        pDict->getAt(_T("ACLYDICTIONARY"),pObjId);

 

 

        if(pObjId.isValid())

        {

          AcDbDictionaryPointer pFiltDict(pObjId,AcDb::kForRead);

          if(Acad::eOk == pFiltDict.openStatus())

          {

            // Get objects in layer filter dictionary

            AcDbObjectId filtObjId;

 

            AcDbDictionaryIterator *pItr = pFiltDict->newIterator();

            if(NULL != pItr)

            {

              for(;!pItr->done();pItr->next())

              {

                AcDbObjectPointer<AcDbXrecord> pLyrFltr(pItr->objectId(),AcDb::kForWrite);

                if(Acad::eOk == pLyrFltr.openStatus())

                {

                  pLyrFltr->erase();

                }       

              }

              delete pItr;

            }

          }    

        }

      }

    }  

  } 

 

  Acad::ErrorStatus es = pDb->saveAs(_T("c:\\drawing1.dwg"));

  delete pDb; 

}

How does FACETRES/VIEWRES relate to AcGiCommonDraw::deviation() in ObjectARX

by Fenton Webb

Issue

Can you please explain in detail how the FACETRES and VIEWRES relate to the deviation() in the AcGiCommonDraw class?

Solution

Deviation – (2D and 3D) This is the value that controls the fineness of the tessellation. As the value goes towards zero, the tessellation goes up.  The deviation represents the error distance between the tessellated line/surface and the actual curve/curved surface.
VIEWRES - (2D and 3D) Controls the appearance of circles, arcs, ellipses, and splines using short vectors. When you raise and lower the value of VIEWRES, objects controlled by both VIEWRES and FACETRES are affected. When you raise and lower the value of FACETRES, only solid objects are affected.  Valid values are from 1 to 20000.  Note the first prompt in VIEWRES is obsolete and unused by AutoCAD - it is only there for script compatibility.

FACETRES - (2D and 3D) Adjusts the smoothness of shaded and rendered objects and objects with hidden lines removed. Valid values are from 0.01 to 10.0. FACETRES controls the smoothness of shaded and rendered curved solids. It is linked to the value set by VIEWRES: when FACETRES is set to 1, there is a one-to-one correspondence between the viewing resolution of circles, arcs, and ellipses and the tessellation of solid objects. For example, when FACETRES is set to 2, the tessellation will be twice the tessellation set by VIEWRES. The default value of FACETRES is 0.5. The range of possible values is 0.01 to 10.

Regarding the deviation calculation, this depends on the AcGiDeviationType.  For kAcGiMaxDevForFacet the formula is:

deviation =1.0 / FACETRES * 0.5 * pixel width.  

Pixel width is calculated as the inverse of the length in pixels of the camera horizontal (x) vector at the camera target.  Also note that in 3D visual styles only the deviation is further affected by the 3DCONFIG surface and curve tessellation sliders.
And, taken from the ObjectARX Reference regarding AcGiCommonDraw::deviation()
The deviation suggests the maximum tessellation deviation. For example, given a curve that is to be represented by line segments, the maximum distance from one of the line segments to its matching part of the curve is to be no less than some amount. The same value is applied to a curved surface that is approximated by a mesh of triangles or quadrangles.

This value helps decide how fine you are allowed to represent a curve with linear or planar elements, that is, to tessellate. In some cases the curve will be so small compared with the deviation amount that the curve may be represented by just one line segment (or triangle or quadrangle) or not at all. Lots of highly resolved tessellation geometry can fill a graphics system quickly, so this value was created to allow the user of the application some control on this effect. This value is only a suggestion.

See AcGiDeviationType for possible values.

Deviation types use the VIEWRES command's zoom percent value (as does AutoCAD's internal tessellation mechanism). The kAcGiMaxDevForFacet uses the FACETRES system variable value as well (as does AutoCAD when faceting surfaces).

When is the selection set returned by acedGetCurrentSelectionSet() valid in ObjectARX?

by Fenton Webb

Issue

I'm confused when acedGetCurrentSelectionSet() should return me a valid Selection Set, can you explain please?

Also, how do I clear the PickFirst Selection Set?

Solution

The function acedGetCurrentSelectionSet() fills an selection set with the object IDs of all entities in the Current Selection Set within AutoCAD. The "Current Selection Set" may be one of the following: a pickfirst set, a selection set selected by the select command or any other command that does a selection (that is, similar to the "Previous" selection option), or the most recent set from calling the function ssget().

You may not get a result calling acedGetCurrentSelectionSet() from a command which does not have the ACRX_CMD_USEPICKSET flag defined. The problem is that you must tell AutoCAD to allow your command to receive the PICK FIRST selection set, otherwise AutoCAD will simply clear it when the command is invoked. Simply add the ACRX_CMD_USEPICKSET to your ACRX_CMD_TRANSPARENT defined command. Be sure to read the ObjectARX Reference guide regarding AcEdCommand::commandFlags for more details.
To clear the PICKFIRST selection set you just need to call acedSSSetFirst(NULL, NULL);

Making your Custom Entity worldDraw or viewportDraw fast

by Fenton Webb

Issue

My Custom Entity is rather complex, whenever my users call the Rotate or Move command or basically do something which requires continual updating of the graphics it becomes very jerky and slow. How can I improve this?

Solution

All of the Graphics Primitive functions housed in the AcGiGeometry class return an Adesk::Boolean. It is this return value that must be checked for a value of True so that AutoCAD can efficiently allow degradation of the graphics redraw in order to maintain UI performance.

If the return value comes back as True it is because the Graphic system calculated that the Minimum Frames Per Second (FPS) setting in the Graphics Configuration is being reached *and* that there is a Mouse interaction already in the input queue waiting to be utilized. A condition of True requires that your worldDraw/viewportDraw returns as quickly as possible back to AutoCAD.

Here is an example:

Adesk::Boolean MyEntity::worldDraw(AcGiWorldDraw *wd)
{
    assertReadEnabled();
    // do some enormous amount of work
    for (int i=0; i<1000000; ++i)
    {
        // check if AutoCAD is telling you that the user has input pending
        if (wd->geometry().circle(.., .., ..))
            return (false); // abort the work, because a new draw is required
    }
}

Enabling the text Search window in AutoCAD 2013 OEM help CHM

by Fenton Webb

Leading on from the How to create your own AutoCAD OEM Help CHM from the 2012/2013 HTML source – here’s how to add the Search box into your OEM Help file.

Simply base your OEM Help on this starter OEM hhp definition and it should work…