GstarCAD 2026 GRX Programming Guide

#GstarCAD#GstarCAD-2026

GstarCAD 2026 GRX Programming Guide

Contents

ae3b17a93ed103c661d43dd9

1. What is GRX?

GRX is the Runtime eXtension programming environment of GstarCAD, which is the latest application development SDK provided with GstarCAD. It provides Object-oriented development environment and APIs based on C++, which can be used to develop GstarCAD application programs, extension CAD classes and protocols, and create new commands in GstarCAD.

GRX is compatible with ARX application programs of AutoCAD® on the source-code level. By simply configuring projects, ARX programs running on the AutoCAD® can be easily ported to the GstarCAD.

GRX SDK allows direct access to GstarCAD database, graphics system and user-defined commands, etc. In addition, it can also be used with VLISP and other programming languages.

Developers only need few configurations to migrate ARX application for AutoCAD® to GRX application for GstarCAD.

The following works can be accomplished with GRX:

  • Access the GstarCAD database

  • Interact with the GstarCAD editor

  • Create user interfaces using the Microsoft® Foundation Classes (MFC) (Windows only)

  • Support the multiple document interface (MDI)

  • Create custom classes

  • Build complex applications

  • Interact with other programming environments

2. Programming Environment

  • Microsoft® Visual Studio 2022 (version 17.8.0)

  • Windows SDK 10.0 (latest installed version)

  • CPU:

Basic: 1.6 GHz CPU

Recommended: 3.0 GHz CPU and above

  • RAM:

Basic: 2 GB

Recommended: 8 GB and above

  • Operation System (OS)

Windows 11

Windows 10 (version 1507 and above):

Home, Professional, Education and Enterprise (not support LTSC and Windows 10 S)

Windows 8.1 (with 2919355 update):

Core, Professional and Enterprise

Windows 7 SP1 (with the latest update):

Home, Professional, Enterprise and Ultimate

  • Monitor Resolution:

1028x800 and above true color display, including 4K (3840x2160) display

  • GstarCAD SDK 2026

  • GstarCAD 2026

  • Microsoft .NET 8.0

3. Install GstarCAD SDK

Download GstarCAD SDK (' GRXSDK.ZIP ' file) from GstarCAD website:

https://www.gstarcad.net/download/

Unzip GRXSDK.ZIP file to the local disk (e.g. 'C:\grxsdk' ) and there will be 5 directories generated (in 'C:\grxsdk' ) which are: arx , inc , inc-x64 , lib-x64 and utils .

arx contains the header files, library files and sample programs used for porting ARX programs to GRX programs. It contains the following directories:

  • inc: Header files used for porting from ARX to GRX

  • inc-x64 : Files used by COM and .NET (for 64-bit)

  • lib-x64 : GRX libraries (for 64-bit)

  • Samples : Sample projects, including dotnet, fact_dg, HelloADS, HelloARX, SimplePalette.

  • Dotnet : .NET programming samples

    1. Addline : .NET programming sample of adding solid lines
    1. Hello : .NET programming sample of outputting prompt information
    1. Vbhello : Sample of .NET programming with VB .NET

  • fact_dg : Sample of LISP function definition

  • HelloADS : Sample of ADS programming

  • HelloARX : Sample of GRX programming

  • SimplePalette : Programming sample of how to create a set Palette windows

  • Utils: Directory contains sub-directories of GRX extended applications, including APIs for extended function development,

e.g. BREP for boundary representation.

inc: Header files used for programming the GRX

inc-x64 : Files used by COM and .NET (for 64-bit) lib-x64 : GRX libraries (for 64-bit)

Utils : Directory contains subdirectories of GRX extended applications, including APIs for extended function development, e.g. BREP for boundary representation.

4. Programming Instruction

  • 4.1. Create GRX Project under Win 64-Bit

  • 4.1.1. Run Microsoft® Visual Studio 2022

Please click File → New → Project to launch the New Project dialog window. Select Visual C++ in the Installed on the left side and click Empty Project in the middle window.

eeefdf09aa031fdab523cbab

4.1.2. Input Project Saving Path and Project Name

Input ' HelloWorld ' at the name field in the New Project dialog window.

6d4aa06b46cea7aed1480fa0

4.1.3. Finish Creating New Project

Click Create button to finish creating a new project.

4.1.4. Create New CPP File

In Visual Studio 2022 dialog window, find the 'HelloWorld' project you just created in the Solution Explorer . Select the 'HelloWorld' project and right click on it, then select Add → New Item . After the Add New Item - HelloWorld dialog window pops out, name the .cpp file as HelloWord.cpp.

822a936d91f61f758cfb73ce 135272c570c9a0204fee91ff

Select the project 'HelloWorld' in the Solution Explorer and select Property at the right click menu. After selecting the Properties option, the HelloWorld Properties Pages pops out.

afd42b19e5c067d7837f17f9
  1. Select General in Configuration Properties and set as below:

Configuration Type : Dynamic Library (.dll)

Windows SDK Version: 10.0(Latest installed version)

Platform Toolset : Visual Studio 2022(v143)

  1. Select Advanced in Configuration Properties and set as below:

Target File Extension: .grx

Character Set: Use Unicode Character Set

  1. Select General in C/C++ and set as below:

General/Additional Include Directories : C:\grxsdk\arx\inc

NOTE

Under debug configuration, please delete _DEBUG macro definition from C/C++ drop down list Preprocessor

-Preprocessor Definitions and set Code Generation / Runtime Library as ' Multi-threaded DLL (/MD)' .

Language / Conformance mode : No

  1. Select Linker and set as below:

General / Additional Library Directories : C:\grxsdk\arx\lib-x64

Input / Additional Dependencies :

AecModeler.lib;gcad.lib;gcax.lib;gcbase.lib;gcbr.lib;gccore.lib;gcdb.lib;GcDbConstraints.lib;GcDbPointCloudObj.lib;gc

dyn.lib;GcGeolocationObj.lib;gcgs.lib;GcImaging.lib;GcModelDocObj.lib;gplot.lib;

Input/Module Definition File: C:\grxsdk\arx\inc\AcRxDefault.def

  1. Click Apply and then click OK to finish the compiler and linker configuration.

  2. Compile the project and make sure that the compilation is successful. Otherwise repeat the above steps to reconfigure the

project settings.

4.1.6. Add Code

Add the following codes to 'HelloWorld.cpp'.

#include "windows.h"
#include <tchar.h>
#include <arxHeaders.h>

void initApp();
void unloadApp();
void HelloWorld();

void initApp()
{
    //register a command with the GstarCAD command mechanism
    acedRegCmds->addCommand(_T("HELLOWORLD_CMDS"), _T("Hello"), _T("Hello"),
ACRX_CMD_TRANSPARENT, HelloWorld);
}
void unloadApp()
{
    acedRegCmds->removeGroup(L"HELLOWORLD_CMDS");
}
void HelloWorld()
{
    //print "Hello World" in GstarCAD command line
    acutPrintf(_T("\nHello World!"));
}

extern "C" AcRx::AppRetCode gcrxEntryPoint(AcRx::AppMsgCode msg, void *pkt)
d97108f4bf1c2533be2d9013 
{
    switch (msg)
    {
case AcRx::kInitAppMsg:
        acrxDynamicLinker->unlockApplication(pkt);
        acrxDynamicLinker->registerAppMDIAware(pkt);
        initApp();
        break;
    case AcRx::kUnloadAppMsg:
        unloadApp();
        break;
    default:
        break;
    }
return AcRx::kRetOK;
}

4.1.7. Compile Program

In Visual Studio 2022, click Build→Build Solution to create 'HelloWorld.grx' file in 'C:\Sample\HelloWorld\x64\Debug' directory.

4.1.8. Run Program

Run GstarCAD and input 'appload' at the command line, or select Tools→Loading Applications from menu to launch Load/Unload

Applications dialog window. Select 'HelloWorld.grx' and click Load to load it into GstarCAD.

4ad1d0a2e94975900f80ac07

Close the Load/Unload Applications dialog window and input ' hello ' at command line, ' Hello World! ' will be displayed at the command line as shown below.

7127c8a82598ec9757d5183f

4.2. GRX Programming with MFC Library

  • 4.2.1. Run Microsoft® Visual Studio 2022

Please click File → New → Project to launch the New Project dialog window. Select Visual C++ in the Installed and click MFC Dynamic-Link Library, then Click Next button.

f7c1fbe5a10705c7e7f41f74

4.2.2. Input Project Saving Path and Project Name

The following sample shows how to create a ' SimplePalette ' project. Name the project as ' SimplePalette' and set the location

'C:\Sample'

ac2989509bbed35161b1a035

4.2.3. Choose DLL Type

Click OK, the MFC DLL dialog window pops out. Select MFC Extension DLL and click OK .

fc36ce34ecbdd2b15ba116ed

4.2.4. Finish Creating New Project

Click OK on New Project dialog window to finish creating ' SimplePalette ' project.

4.2.5. Create New Resource and Corresponding Class

Launch the Resource View of Visual Studio 2022 (Ctrl+Shift+E), right click on ' SimplePalette.rc ' and select Add Resource… in the drop-down menu to pop out Add Resource dialog window. Select Dialog in the Resource Typ e window and click New to add a new dialog. Change the ID of newly created ' IDD_DIALOG1 ' dialog to ' IDD_DIALOG_PALETTE '. Right click on ' IDD_DIALOG_PALETTE ' and select Properties to set Border as ' None ', Style as ' Child' . Then add an Edit Control and a Button from Toolbox (Ctrl+Alt+X) and change the button Caption to ' Check ' and the ID to ' IDC_BUTTON_CHECK ', as shown below.

f5d475f3356713b4cb3385b5 b2c82679f76b096f3cb3e2fa eb091dc84512fada27b1ea37 a04406d49cc4efa18e391bec 1cc136b7bac67c07bb0a5075

Right click on the newly created ' IDD_DIALOG_PALETTE ' dialog and select the Add Class… to pop out Add MFC Class dialog window. Set Class Name as ' CDlgPalette ' and click OK .

352ef61d2cc8c97da15c8432 289479db28d53fcea5007555

4.2.6. Create Three New C++ Class File

In the Solution Explorer of Visual Studio 2022, right click on the project 'SimplePalette' and select Add→Class… to pop out Add

Class dialog window, as shown below. Add 3 new classes named as 'CFirstPalette', 'CSecondPalette' and 'CSimpleBar' and set the

Base class as 'CAdUiPalette', 'CAdUiPalette' and 'CAdUiPaletteSet' respectively.

51054873b795b1e613fdbf82

4.2.7. Add Code

Add the following codes to the end of 'pch.h' file:

#include <arxHeaders.h>

Add the following codes to the beginning of 'CDlgPalette.h' Head File:

#include "resource.h"

(For the class codes of 'CDlgPalette', 'CFirstPalette', 'CSecondPalette' and 'CSimpleBar', please refer to samples (.cpp and .h files)

of 'CDlgPalette', 'CFirstPalette', 'CSecondPalette' and 'CSimpleBar' in 'C:\grxsdk\arx\samples\SimplePalette')

Add the following codes to 'SimplePalette.cpp':

// SimplePalette.cpp: Defines the initialization routines for the DLL.
//

#include "pch.h"
#include "framework.h"
#include "CSimpleBar.h"

CSimpleBar* gpBar = NULL;

static void doIt()
{
    if (gpBar)
    {
        acedGetAcadFrame()->ShowControlBar(gpBar, TRUE, FALSE);
    }
    else
    {
        acedInitGet(0, L"Float Dock");
        ACHAR result[132] = { 0 };
        int rc = acedGetKword(L"\nFloat or Docking?", result);
        bool bFloat = true;
        if (rc == RTNONE)
        {
            bFloat = true;
        }
        else if (rc != RTNORM)
        {
            return;
        }
        else
        {
            bFloat = _wcsicmp(result, L"Float") == 0;
        }

        CSize sizeDefault(400, 450);
        CRect rcDefault(CPoint(150, 200), sizeDefault);

        gpBar = new CSimpleBar;

        DWORD dwStyle = WS_CHILD | WS_VISIBLE | CBRS_SIZE_DYNAMIC | CBRS_GRIPPER;
        if (bFloat)

        {
            dwStyle |= CBRS_FLOATING;
        }
        else
        {
            dwStyle |= CBRS_LEFT;
        }

        gpBar->Create(L"Simple", dwStyle, rcDefault, acedGetAcadFrame());
        gpBar->SetAutoRollup(FALSE);
        gpBar->EnableDocking(CBRS_ALIGN_LEFT | CBRS_ALIGN_RIGHT |
CBRS_ALIGN_BOTTOM);
        if (bFloat)
        {
            acedGetAcadFrame()->FloatControlBar(gpBar, CPoint(100, 100), CBRS_ALIGN_TOP);
        }
        else
        {
            acedGetAcadFrame()->DockControlBar(gpBar, AFX_IDW_DOCKBAR_RIGHT);
        }
    }
}

void initApp()
{
    acedRegCmds->addCommand(_T("ASDK_SAMPLES_SIMPLEPALETTE"),
        _T("ASDK_SIMPLEPALETTE"), _T("SIMPLEPALETTE"), ACRX_CMD_MODAL,
        doIt);
}

void unloadApp()
{
    acedRegCmds->removeGroup(_T("ASDK_SAMPLES_SIMPLEPALETTE"));

    if (gpBar)
    {
        gpBar->DestroyWindow();
        delete gpBar;
        gpBar = NULL;
    }
}
e40400c8d64ec4c71aeb267c 
extern "C" AcRx::AppRetCode
acrxEntryPoint(AcRx::AppMsgCode msg, void* appId)
{
    switch (msg) {
    case AcRx::kInitAppMsg:
        acrxDynamicLinker->unlockApplication(appId);
        acrxDynamicLinker->registerAppMDIAware(appId);
        initApp();
        break;
    case AcRx::kUnloadAppMsg:
        unloadApp();
    }
    return AcRx::kRetOK;
}
Note

Please delete the following code in CDlgPalette.h

 //#ifdef AFX_DESIGN_TIME
    //#endif
44a5fb8e67fb6b643a2c7a8c
  1. In the Solution Explorer , right click the project ' SimplePalette ' and select Properties to pop out the SimplePalette Properties Pages dialog window. The following settings in this section are completed in this dialog window.
51daf801d3b7c3b4942d7e16
  1. Select General in Configuration Properties and set as below:

Configuration Type : Dynamic Library (.dll)

Windows SDK Version: 10.0(Latest installed version)

Platform Toolset : Visual Studio 2022(v143)

  1. Select Advanced in Configuration Properties and set as below:

Target File Extension: .grx

Character Set: Use Unicode Character Set

  1. Select General in C/C++ and set as below:

General-Additional Include Directories : C:\grxsdk\arx\inc

NOTE

Under debug configuration, please delete _DEBUG macro definition from C/C++ drop down list Preprocessor

-Preprocessor Definitions and set Code Generation / Runtime Library as ' Multi-threaded DLL (/MD)' .

Language-Conformance mode : No

  1. Select Linker and set as below:

General / Additional Library Directories : C:\grxsdk\arx\lib-x64

Input / Additional Dependencies :

AecModeler.lib;gcad.lib;gcax.lib;gcbase.lib;gcbr.lib;gccore.lib;gcdb.lib;GcDbConstraints.lib;GcDbPointCloudObj.lib;gc dyn.lib;GcGeolocationObj.lib;gcgs.lib;GcImaging.lib;GcModelDocObj.lib;gplot.lib;

Input / Module Definition File : C:\grxsdk\arx\inc\AcRxDefault.def

Advanced/Target Machine: Machine X64

  1. Click Apply and then click OK to finish the compiler and linker configuration.

  2. Compile the project and make sure that the compilation is successful. Otherwise repeat the above steps to reconfigure the project settings.

4.2.9. Compile Program

In Visual Studio 2022, click Build → Build Solution to create ' SimplePalette.grx ' file in the ' C:\Sample\SimplePalette\x64\Debug ' directory.

4.2.10. Run Program

Run GstarCAD and input ' appload ' at the command line, or select Tools → Loading Applications from menu to launch Load/Unload

Applications dialog window. Select ' SimplePalette.grx ' and click Load to load it into GstarCAD.

368c44e9e727b9558c7b5038

Close the Load/Unload Applications dialog window and input ' simplepalette ' at command line, ' Float or Docking? ' will be displayed at the command line. Press Enter key and a dialog window will pop out as shown below.

ec9156ed2f4f593d71592ade

5. Description of GRX Class Library

The following libraries are frequently used in programming with GRX. These libraries have same functions with the corresponding ARX libraries.

  • GcRx : same as AcRX of ARX , classes for binding an application and for runtime class registration and identification

  • GcEd : same as AcEd of ARX , classes for registering commands and for event notification

  • GcDb : same as AcDb of ARX , GstarCAD database class

  • GcGi : same as AcGi of ARX , graphics classes for rendering entities

  • GcGe : same as AcGe of ARX , utility classes for common linear algebra and geometric objects

5.1. GcRx

The GcRx class library provides system-level functionality such as DLL initialization and linking, and runtime class registration and identification as below:

  • Object runtime class identification and inheritance analysis

  • Runtime addition of new protocol to an existing class

  • Object equality and comparison testing

  • Object copy

5.2. GcEd

The GcEd class library is used to define and register new GstarCAD commands which operate in the same manner as the original ones.

5.3. GcDb

The GcDb classes are components of the GstarCAD database. This database stores all the information for the graphical objects that compose a drawing, and the non-graphical objects (such as layers, linetypes, and text styles) that are also part of a drawing.

5.4. GcGi

The GcGi class library provides the graphic interface used for drawing CAD entities.

5.5. GcGe

The GcGe class library provides classes used for performing common 2D and 3D geometric operations, including utility classes such as vectors and matrices and basic geometric objects such as points, curves, and surfaces.

6. About the use of macro OBJECTPARAM_ALLOWED

In order to be compatible with ObjectARX2025, in GRX2026 of GstarCAD, if GcString is passed into a variable parameter function such as gcutPrintf , it is necessary to call GcString :: constPtr (); as follows:

Previous version:

_GcString sz ; gcutPrintf ( T( " \ n%s " ), sz ); 2026 Edition GcString sz ;

_gcutPrintf ( T( " \ n%s " ), sz.constPtr ());

If this modification is not made ( i.e. constPtr () is not called), a compilation error will be reported when GRX is compiled:

error C4840: non-portable use of class " GcString " as argument to variadic function

Developers can use this compilation error to modify the code where GcString is called in previous versions.

This compatibility change will result in a compilation error when CStirng is passed into a variable parameter function such as gcutPrintf :

error C4840: non-portable use of class "ATL::CStringT<wchar_t,StrTraitMFC_DLL<wchar_t,ATL::ChTraitsCRT<wchar_t>>>" as argument to a variadic function

At this point, you can choose one of the following two methods to modify it:

Method 1: Change to

_gcutPrintf ( T("%s"), sz.GetBuffer ()); or

_gcutPrintf ( T("%s"), ( LPCTSTR ( sz )));

Method 2: After modifying all GcString codes , add OBJECTPARAM_ALLOWED definition in the project configuration . This macro definition can ignore all such compilation errors. As shown below.

46c7136e1573fb0941d423cb

Copyright reserved: Gstarsoft Co.,Ltd

Copying and referencing any part of this document is allowed. No part of this document may be changed without permission. Please keep this statement when copying or referencing this document.

14f8f163bb617cccb1e71de5

Links to this page:

  1. Welcome