Calculate extents of text with True Type fonts

By Augusto Goncalves

It is possible to manually obtain the extents of a AcDbText, which is shown below. This can be also used to get the space a text will occupy. This sample code uses a existing text style and call the extents method.

Acad::ErrorStatus getTTFTextGeomExtents(
                    AcDbText *pText,
                    AcDbExtents& extents)
{

Acad::ErrorStatus es;           if(!pText)        return Acad::eInvalidInput;           // Create an AcGiTextStyle based on the text's style.      AcDbObjectId textStyleId=pText->textStyle();      AcGiTextStyle *pTextStyle=new AcGiTextStyle;      if((es=fromAcDbTextStyle(*pTextStyle,textStyleId))!=Acad::eOk)        return es;      pTextStyle->setTextSize(pText->height());           // Get the 2d Extents of the text string      // (using the applied style), and convert it to a 3d point.      AcGePoint2d extentsPoint2d=pTextStyle->extents(        pText->textString(),false,_tcslen(pText->textString()),        false,NULL);      AcGePoint3d extentsPointA(0,0,0),extentsPointB(        extentsPoint2d[0],extentsPoint2d[1],0);           // AcDbText::getEcs() returns an Identity matrix,      // so we must create the transform matrix ourselves.      AcGeMatrix3d coordSysMat;      AcGeVector3d xAxis = pText->normal().perpVector();      AcGeVector3d yAxis = pText->normal().crossProduct(xAxis);      xAxis.rotateBy(pText->rotation(),pText->normal());      yAxis.rotateBy(pText->rotation(),pText->normal());      coordSysMat.setCoordSystem(pText->position(), xAxis,         yAxis, pText->normal());           // Use the matrix to transform our extents to WCS.      extentsPointA.transformBy(coordSysMat);       extentsPointB.transformBy(coordSysMat);           extents.addPoint(extentsPointA);      extents.addPoint(extentsPointB);           delete pTextStyle;      return Acad::eOk;    }