70002829 Command to compare two drawings

Summary

Command to compare two drawings and the differences

Solution

In version 12.0.01 new methods were added to provide the functionality of comparing two drawings.

1.vdDocument.Compare(vdDocument with) as IvdCompareResults
  Compare this document's Model Entities 'with' the passed document
  Recommended to compare drawings of the same type/extension (for example compare two dwg drawings or two vdml drawings).
  Remarks : 
  Double value properties are compared using the vdDocument.FileProperties.CompareDocumentSettings.DecimalPrecision which by default is 8.
  vdDocument.FileProperties.CompareDocumentSettings.CollectionLimit variable defines the maximun number of objects that a collection property of a vdFigure can have in order to be valid for comparing
  If a figure has a collection property that exceeds this number then this figure is marked as Incomparable.Default value of CollectionLimit is 0 for no limit and all figures are comparable (examples of such figures is an insert with it's block having many items or a polyface having a lot of gPoints.
  Only some of the basic geometrical properties of each figure type participate in the comparison.This is done for performance reasons. See Section 4 for details for each figure.

  Following entity types are Incomparable
      vdIFC object types
      user develop custom objects .These objects must override the vdFigure.GetCompareHash method (example at the bottom of this article).

  returns a IvdCompareResults object that contains information about the compare results
  The IvdCompareResults has the following properties

  Drawing1Common  as vdSelection  : Returns the collection of entities that belong to the first document and are same as entities in the second document.
  Drawing1Exclusive  as vdSelection  : Returns the collection of entities that belong to the first document and do not exist in the second document.
  Drawing1Modified  as vdSelection  : Returns the collection of entities that belong to the first document and exist in the second document, but with some of their properties modified.
  Drawing1Incomparable  as vdSelection  : Returns the collection of entities that belong to the first document and are Incomparable (do not implement  method).
  Drawing2Common  as vdSelection  : Returns the collection of entities that belong to the second document and are the same with corresponding entities in the second document.
  Drawing2Exclusive  as vdSelection  : Returns the collection of entities that belong to the  second document and do not exist in the first document.
  Drawing2Modified  as vdSelection  : Returns the collection of entities that belong to the second document and exist in the first document, but with some of their properties modified.
  Drawing2Incomparable  as vdSelection  : Returns the collection of entities that belong to the second document and are Incomparable (do not implement  method).
  NumberofDiffs as Integer : Returns the number of differences between the drawings.

2.vdCommandAction.CmdCompare( object Drawing1Path, object Drawing2Path, bool navigate) as integer
  Compare two drawings and visualize the result in this Document object
  Remarks
   Allows you to quickly identify differences between two versions of a drawing, displaying changes with color coding.
   Strongly recommended to compare drawings of the same type/extension; When non-VDF drawings (like .DGN, .DXF, .PDF etc) are imported into VDF then some of their objects might be translated
        to different VDF objects and vice versa. So by comparing drawings of different files types then command may return differences although on-screen the files look exactly the same.
   Two block references are added to this document one foreach compare document
   The comparison works only for objects in Model Space
   Double value properties compare using the vdDocument.FileProperties.CompareDocumentSettings.DecimalPrecision which by default is 8
   Color Coding:
      vdDocument.FilePropertis.CompareDocumentSettings.SameObjectsColor :Objects that are same in both drawings. Default value is Color.Gray
      vdDocument.FilePropertis.CompareDocumentSettings.NoMatchingObjectsColor1 : Objects in drawing1 that are not matching any object from drawing2. Default value is Color.Red
      vdDocument.FilePropertis.CompareDocumentSettings.NoMatchingObjectsColor2 :  Objects in drawing2 that are not matching any object from drawing1. Default value is Color.Green
      vdDocument.FilePropertis.CompareDocumentSettings.DifferentObjectsFadeEffect :Fade Effect for objects of same type same handle on both drawings but different properties. Default value is 25
      vdDocument.FilePropertis.CompareDocumentSettings.RectangleColor : Rectangles that groups the neighboring changes. Default value is Color.Yellow
      vdDocument.FilePropertis.CompareDocumentSettings.IncomparableObjectsColor : Objects that are Incomparable usually do not support comparison. Default value is Color.LightGray

    Drawing1Path:  Drawing 1 to compare
    Drawing2Path  Drawing 2 to compare with.
    navigate       If it is true waiting for the user to press the arrows keys to automatically zoom to the yellow rectangle areas where there is a difference.
    Returns 0 if there are no differences >0 if there are differences , -1 on error

3.A new virtual method was added in vdFigure  int GetCompareHash()
   Called when this object is going to be compared with another object by vdDocument.Compare
   Override this method to your custom object and return a unique 32 bit integer value according to the object type and its properties
   Example override GetCompareHash method in order your custom object to be comparable

   public class CustomObject : vdFigure , IvdProxyFigure
   {

     gPoint mOrigin = new gPoint();
     Vector mNormal = new Vector();
     double mRotation = 0;//in radians
     int mIntvalue = 0;
     string mDisplayText = "";

     gPoints mpoints = new gPoints();
     vdEntities mSomeEntities = new vdEntities();
     Int32Array mIntCollection = new Int32Array();
     DoubleArray mDoubleCollection = new DoubleArray(); 


     public override int GetCompareHash()
     {

       unchecked 
       {
           int hash = 17;//start with this line
           hash = hash * 23 + GetType().GetHashCode();//always put this at the start and follow the object properties

           int hash2 = mpoints.GetCompareHashCode();
           if(hash2 == 0) return 0;//always check the collections depend on the vdDocument.FileProperties.CompareDocumentSettings.CollectionLimit
           hash = hash * 23 + hash2;

           hash2 = mSomeEntities.GetCompareHashCode();
           if(hash2 == 0) return 0;//always check the collections depend on the vdDocument.FileProperties.CompareDocumentSettings.CollectionLimit
           hash = hash * 23 + hash2;

           hash2 = mIntCollection.GetCompareHashCode();
           if(hash2 == 0) return 0;//always check the collections depend on the vdDocument.FileProperties.CompareDocumentSettings.CollectionLimit
           hash = hash * 23 + hash2;

           hash2 = mDoubleCollection.GetCompareHashCode();
           if(hash2 == 0) return 0;//always check the collections depend on the vdDocument.FileProperties.CompareDocumentSettings.CollectionLimit
           hash = hash * 23 + hash2;


           hash = hash * 23 + Globals.GetCompareHash(mOrigin);
           hash = hash * 23 + Globals.GetCompareHash(mNormal);
           hash = hash * 23 + Globals.GetCompareHashAngle(mRotation);//use GetCompareHashAngle for rotation in radians
           hash = hash * 23 + mIntvalue.GetHashCode();
           hash = hash * 23 + mDisplayText.GetHashCode();
        
           return hash;
       }
     }


}

4.Properties of figure types that  participate in the comparison

vdArcAlignedText
	TextString
	Style //uses the Name
	Height
	Center
	Radius
	StartAngle
	EndAngle

vd3DFace
	VertexList

vdArc
	Center
	Radius
	StartAngle
	EndAngle
	HatchProperties //uses FillMode property

vdAttrib
	base vdText properties and..
	TagString
	ValueString
	InVisibleMode

vdAttribDef
	base vdText properties and..
	TagString
	ValueString

vdCircle
	Center
	Radius
	HatchProperties //uses FillMode property

vdDimension
	DefPoint1
	DefPoint2
	DefPoint3
	DefPoint4
	TextPosition
	LinePosition
	Style //uses Name
	dimText
	dimType
	UsingDefaultTextPosition
	Rotation
	HorizontalRotation

vdEllipse
	Center
	MajorLength
	MinorLength
	MajorAngle
	StartAngle
	EndAngle
	HatchProperties //uses FillMode property

vdGroundSurface
	Points
	LockTriangles

vdHelix
	BaseCenter
	BaseRadius
	TopRadius
	Height
	TurnHeight
	Turns
	Twist
	Constrain
	StartAngle

vdImage
	base vdRectText properties and..
	ImageDefinition
	ImageScale

vdInfinityLine
	BasePoint
	Direction
	InfinityType

vdInsert
	InsertionPoint
	Xscale
	Yscale
	Zscale
	Rotation
	Attributes
	Block //uses Name and block entire Entities

vdLeader
	VertexList
	LeaderMText
	LeaderType
	Style ///uses the Name

vdLine
	StartPoint
	EndPoint

vdMtext
	TextString
	Style //uses Name
	BoxWidth
	Height
	Rotation
	InsertionPoint

vdMultiLine
	Flags
	Justification
	MultilineStyle //uses the Name
	ScaleFactor
	VertexList

vdPoint
	InsertionPoint

vdPointCloud
	points
	ECSMatrix

vdPolyface
	VertexList
	FaceList


vdPolyHatch
	HatchProperties //uses FillMode property
	PolyCurves // entire collection comparer

vdPolyline
	Flag
	VertexList
	SPlineFlag
	HatchProperties //uses FillMode property

vdRect
	InsertionPoint
	Width
	Height
	Rotation
	HatchProperties //uses FillMode property

vdText
	InsertionPoint
	TextString
	Style // uses the Name
	VerJustify
	HorJustify
	Rotation
	AlignmentPoint
	Height


Note:
the Compare command is also added 
in commands.txt resource, that make a call to vdCommandAction.CompareEx static method
in the menu.txt resource, in File sub-menu section

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