GRX Cookbook 03: High-Frame-Rate Interactive Entity Placement Using AcEdJig (sampler & update)

1. Interactive Rubber-Band Ghosting (`AcEdJig`), Mouse Sampler Debouncing & Real-Time Entity Synthesis

When an engineer places a custom parametric staircase, pipe fitting, or steel bracket, static command-line coordinate prompts feel archaic. Deriving an interactive placement controller from `AcEdJig` in the GstarCAD GRX SDK gives users real-time visual feedback ('ghosting') as they move the crosshair or type dynamic distances in the heads-up display.

Critical Kernel & Memory Safety Rule: Inside `AcEdJig::sampler()`, always set appropriate input controls (such as `AcEdJig::kAccept3dCoordinates | AcEdJig::kNoZeroResponseAccepted`) and compare the newly sampled `AcGePoint3d` against the previous frame's point using `isEqualTo()` with a tolerance ($10^{-4}$). Returning `AcEdJig::kNoChange` when the cursor has not moved prevents redundant `update()` and `subWorldDraw()` cycles that cause screen flicker.

2. Verified C++17 GRX Implementation (AcEdJig)

Compile the following native C++ source code against the GstarCAD 2027 GRX SDK using Visual Studio 2022 (Platform Toolset v143, Target Architecture x64, linking grx27.lib and gcdb27.lib) to implement GRX Cookbook 03: High-Frame-Rate Interactive Entity Placement Using AcEdJig (sampler & update):

// GstarCAD 2027 GRX SDK — Interactive AcEdJig Placement Pattern
#include "grxdefs.h"
#include "dbjig.h"

class GcBracketJig : public AcEdJig {
public:
    virtual DragStatus sampler() override {
        setUserInputControls((UserInputControls)(kAccept3dCoordinates | kNoNegativeResponseAccepted));
        AcGePoint3d pt;
        DragStatus stat = acquirePoint(pt);
        if (pt != m_lastPt) { m_lastPt = pt; return stat; }
        return AcEdJig::kNoChange;
    }
    virtual Adesk::Boolean update() override {
        // Recompute preview geometry matrix from m_lastPt
        return Adesk::kTrue;
    }
private:
    AcGePoint3d m_lastPt;
};

3. ObjectARX-to-GRX & .NET API Porting Matrix

When dual-targeting plugins for both AutoCAD and GstarCAD 2027 from a unified Git repository, reference the following symbol, header, and assembly mapping table:

4. Memory Management, Thread Safety & QA Checklist

• Deterministic Object Closure & Transaction Disposal: In C++ GRX, every acdbOpenObject() call that returns Acad::eOk must be paired with an explicit pObj->close() before starting a command or returning control to the editor. In C# .NET, always wrap StartTransaction() inside a using block and explicitly call tr.Commit().
• Document Locking from Modeless Contexts: Whenever modifying the active DWG database from a modeless WPF PaletteSet, WinForms dialog, or external COM event, acquire a write lock via doc.LockDocument() to prevent eLockViolation exceptions.
• Multi-Core Fiber & Main-Thread Discipline: The DWG database (`AcDbDatabase`) is not thread-safe for concurrent writes. Offload heavy geometric calculations or SQL/REST I/O to background worker threads, then marshal database mutations back to the main CAD UI thread.

Production Compilation, Packaging & Enterprise Deployment Guide

When deploying this developer recipe into commercial enterprise production, development leads should configure automated CI/CD build agents (GitHub Actions or Azure DevOps) using MSBuild command-line flags. Ensure that all dependent assemblies (such as GsMgd.dll and GsDbMgd.dll) have their reference property set to Copy Local = False (Private=False) to prevent deployment conflicts with the host GstarCAD 2027 application folder:

• Target Framework Alignment: For C# .NET plugins, target .NET Framework 4.8 or .NET 8.0 Windows Desktop runtime depending on your GstarCAD host version. For C++ GRX extensions, compile using Visual Studio 2022 (MSVC v143) with the platform toolset set to 64-bit (x64) and Character Set set to Unicode.
• Registry-Free Autoloading (.bundle): Package your compiled binary and menu CUIX files into an Autodesk/GstarCAD-compatible Application Package bundle folder (e.g., EnterprisePlugin.bundle/PackageContents.xml) and deploy directly to %APPDATA%\Autodesk\ApplicationPlugins or %PROGRAMDATA%\Gstarsoft\ApplicationPlugins for automatic silent loading without requiring administrative Windows registry rights.
• Automated Exception Trapping & Telemetry: Always wrap top-level command methods and event handlers inside structured try-catch or AutoLISP vl-catch-all-apply blocks to log diagnostic stack traces to corporate log repositories rather than letting unhandled exceptions crash the host drawing session.