Hello,
On this class I will complete the Class 13 with a tutorial to show you how to create a simple custom entity step by step. This entity has some features that will help you to see what is possible to do using ObjectARX. Please read carefully the following instructions.
-Create a
Blank Solution called
CustomEntitySample;
-Add a new
DBX project called
CustEntityDBX;
-Add a new
ARX project called
CustEntityARX;
-Remember to
enable MFC Extension on both projects;
-Create a
dependency from ARX project to DBX:
-Go to DBX project and open Autodesk Class Explorer;
-Right click on CustEntityDBX node and select "Add ObjectDBX Custom Object...":
-Choose MyCustomEntity as class name and derive it from AcDbEntity;
-Other fields will be filled automatically (you may change these values);
-Go to the Protocols TAB and enable both Osnap and Grip-points protocols:
-Rebuild your project to see if everything is ok;
-Now, open again the Autodesk Class Explorer, go to CustEntityDBX project;
-Select the MyCustomEntity node (if it is not there, click on Refresh icon);
-Right click on it and select "Add Variable...":
-Name it as "
m_PtA", type will be an
AcGePoint3d and its access will be protected;
-Enable "
Participate to DWG filing protocol", disable "
Increase Version number";
-Enable "
Implement Get/Put methods" and fill desired comments for it;
-Repeat the process and create : "
m_PtB", "
m_PtAB" and "
m_PtBA":
-Now, add a CString variable called "m_Text";
-Remember to correct the CString manipulation and filing as we have done in Lab3;
-Now you should compile your code ok;
Before continue, we will need to remove some functions that we will not use. First remove the following from .H file:
virtual Acad::ErrorStatus getGripPoints (
AcDbGripDataPtrArray &grips, const double curViewUnitSize, const int gripSize,
const AcGeVector3d &curViewDir, const int bitflags) const;
virtual Acad::ErrorStatus moveGripPointsAt (
const AcDbVoidPtrArray &gripAppData,
const AcGeVector3d &offset, const int bitflags);
There are 4 methods getOsnapPoints(). We will only use the following method:
virtual Acad::ErrorStatus getOsnapPoints (
AcDb::OsnapMode osnapMode, int gsSelectionMark, const AcGePoint3d &pickPoint,
const AcGePoint3d &lastPoint, const AcGeMatrix3d &viewXform,
AcGePoint3dArray &snapPoints, AcDbIntArray &geomIds) const ;
Now, you will need to delete the body of these functions from cpp file.
WORLDDRAW
-To draw our custom entity, we will need to add the following code to worldDraw() method:
assertReadEnabled();
// Bounding Polyline
AcGePoint3d pts[4];
pts[0] = m_PtA;
pts[1] = m_PtAB;
pts[2] = m_PtB;
pts[3] = m_PtBA;
mode->subEntityTraits().setSelectionMarker(1); // Mark 1
mode->subEntityTraits().setColor(1); // Red
mode->geometry().polygon(4,pts);
// Entity's Text
mode->subEntityTraits().setSelectionMarker(2); // Mark 2
mode->subEntityTraits().setColor(256); // ByLayer
AcGiTextStyle style;
style.setFileName(_T("txt.shx"));
style.setBigFontFileName(_T(""));
style.setTextSize(25);
style.loadStyleRec();
AcGePoint3d txtPt((m_PtB.x+m_PtA.x)/2.0, (m_PtB.y+m_PtA.y)/2.0, m_PtA.z);
mode->geometry().text(txtPt, AcGeVector3d::kZAxis,
(m_PtAB-m_PtA),m_Text, m_Text.GetLength(),Adesk::kFalse, style);
return Adesk::kTrue;
GRIP Points
-Open remaining getGripPoints() method inside MyCustomEntity implementation (cpp);
-We would like to enable 5 grips for this entity. One at each point (A,B,AB and BA) plus one at the center;
-Inside the getGripPoints(), add the following code:
gripPoints.append(m_PtA);
gripPoints.append(m_PtAB);
gripPoints.append(m_PtB);
gripPoints.append(m_PtBA);
gripPoints.append(AcGePoint3d((m_PtB.x+m_PtA.x)/2.0,
(m_PtB.y+m_PtA.y)/2.0,m_PtA.z));
-Now, when user clicks on each Grip we would like to perform an action. This is done using the moveGripPointsAt() method;
-We need to check the index of each fired grip accordingly to the getGripPoints() method and then apply the transformation;
-Inside remaining moveGripPointsAt() method, add the following code:
assertWriteEnabled();
for(int i=0; i<indices.length(); i++) {
int idx = indices.at(i);
// For A and center point
if (idx==0 idx==4) m_PtA += offset;
// For AB and center point
if (idx==1 idx==4) m_PtAB += offset;
// For B and center point
if (idx==2 idx==4) m_PtB += offset;
// For BA and center point
if (idx==3 idx==4) m_PtBA += offset;
}
return (Acad::eOk);
OSNAP Points
-Open the getOsnapPoints() method. We will add 3 Osnap modes: EndPoint, MidPoint and Center:
assertReadEnabled();
switch (osnapMode) {
case AcDb::kOsModeEnd:
snapPoints.append(m_PtA);
snapPoints.append(m_PtAB);
snapPoints.append(m_PtB);
snapPoints.append(m_PtBA);
break;
case AcDb::kOsModeMid:
snapPoints.append(m_PtA+((m_PtAB-m_PtA).length()/2.0)*((m_PtAB-m_PtA).normalize()));
snapPoints.append(m_PtAB+((m_PtB-m_PtAB).length()/2.0)*((m_PtB-m_PtAB).normalize()));
snapPoints.append(m_PtB+((m_PtBA-m_PtB).length()/2.0)*((m_PtBA-m_PtB).normalize()));
snapPoints.append(m_PtBA+((m_PtA-m_PtBA).length()/2.0)*((m_PtA-m_PtBA).normalize()));
break;
case AcDb::kOsModeCen:
snapPoints.append(AcGePoint3d((m_PtB.x+m_PtA.x)/2.0,
(m_PtB.y+m_PtA.y)/2.0, m_PtA.z));
break;
}
return (Acad::eOk);
TRANSFORMATION-The custom entity transformation is done through
transformBy() method;
-Open the
Autodesk Class Explorer, expand the
MyCustomEntity node, expand
Base Classes node and then expand
AcDbEntity node;
-Scroll down the list and select:
Acad::ErrorStatus transformBy(const AcGeMatrix3d &);-
Right click on this method and select "
Implement Base Class Method";
-This function logic is very simple, just add the following code:
assertWriteEnabled();
m_PtA.transformBy(xform);
m_PtAB.transformBy(xform);
m_PtB.transformBy(xform);
m_PtBA.transformBy(xform);
return (Acad::eOk);
-This function will allow the custom entity to be transformed;
ARX PROJECT-First we will need to add a new command called "
MyCustEnt";
-This will create a method inside
acxrEntryPoint.cpp file;
-Now, add the necessary include instruction after the #include "StdAfx.h":
#include "..\CustEntityDBX\MyCustomEntity.h"
-Inside the method we will create our entity:
// Input information
ads_point pt1,pt2;
if (acedGetPoint(NULL,_T("Set the first point:\n"),pt1) != RTNORM)
return;
if (acedGetCorner(pt1,_T("Set the second point:\n"),pt2) != RTNORM)
return;
TCHAR buffer[512];
if (acedGetString(0,_T("Enter the text:\n"),buffer) != RTNORM)
return;
// Setup entity
MyCustomEntity *pEnt = new MyCustomEntity();
pEnt->put_m_PtA(asPnt3d(pt1));
pEnt->put_m_PtAB(AcGePoint3d(pt2[X],pt1[Y],pt1[Z]));
pEnt->put_m_PtB(asPnt3d(pt2));
pEnt->put_m_PtBA(AcGePoint3d(pt1[X],pt2[Y],pt2[Z]));
pEnt->put_m_Text(buffer);
// Post to Database
AcDbBlockTable *pBlockTable;
acdbHostApplicationServices()->workingDatabase()->getSymbolTable(pBlockTable,
AcDb::kForRead);
AcDbBlockTableRecord *pBlockTableRecord;
pBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord,AcDb::kForWrite);
pBlockTable->close();
AcDbObjectId retId = AcDbObjectId::kNull;
pBlockTableRecord->appendAcDbEntity(retId, pEnt);
pBlockTableRecord->close();
pEnt->close();TEST-
Rebuild your project;
-Open AutoCAD and load
DBX module first and then load the ARX;
-Fire command
MYCUSTENT and create as many entities as you want;
-Test it against GRIP edit, MOVE, ROTATE, SCALE;
-Fire a LINE command and try to get precision points (EndPoint, MidPoint and Center) over your entities;
