JXNSNAP-bgol (Snap Text to Junction Point)

Command Type: AutoLISP routine (works in AutoCAD, BricsCAD, ZWCAD and most AutoLISP-compatible CAD platforms)
Developed by: BGol Community, bgol.in

Inspired by the general concept of nearest-endpoint text snapping utilities used in CAD network/infrastructure drafting. This is an original, independently written routine, new file name, new command name, new source code, created so the CAD community has a free, editable, open-source alternative.

Overview

SNJP snaps junction-number text (drainage, water, or road-network node labels) to the nearest polyline endpoint, precisely aligning annotation with the network geometry it describes. If two or more labels compete for the same nearest endpoint, SNJP doesn't guess, it flags them instead, recoloring them red on a dedicated layer so you can resolve the conflict manually.

How to Use

1. Load JXNSNAP-bgol.lsp into your CAD session (drag-and-drop the file onto the drawing window, or use the APPLOAD command).
2. Type SNJP at the command line and press Enter.
3. Select the junction-number text entities you want to snap.
4. Select the candidate polylines (the network lines) to snap to.
5. Enter a search radius when prompted (defaults to 5.0 drawing units).
6. Each text entity is moved to its nearest polyline endpoint if that endpoint is within range and not contested by another text. Any text whose nearest endpoint is shared with another text is left in place and switched to layer BGOL-SNJP-FLAG (colour red) for manual review.

Why Use It

• Time-saving, automates aligning many junction-number labels to their correct polyline endpoints, eliminating tedious manual snapping in complex polyline networks.
• Improved accuracy, ensures text is precisely aligned to the actual network geometry, reducing risk of mislabeled or ambiguously-placed junction annotation.
• Conflict detection, proactively flags ambiguous cases (multiple texts near one endpoint) rather than silently guessing, preventing overlapping annotations.

Where to Use It

• Annotating utility or drainage network junctions with numbers that must align exactly to network node locations.
• Cleaning up survey or infrastructure drawings where junction labels have drifted from their true node positions.
• Any network-diagram QA pass verifying and correcting label-to-node alignment.

Notes

• Endpoints considered are each candidate polyline's start and end point; intermediate vertices are not currently checked.
• The search radius limits how far a text can move, text with no endpoint within range is left untouched.
• Flagged (ambiguous) text keeps its original position; only its layer and colour change, so nothing is silently mis-snapped.
• Source code is fully open, feel free to study, modify, and redistribute it under the same open, free-for-all spirit.

Credits

Developed and shared for the CAD community by BGol Community. Website: https://bgol.in/ Free and open-source, use it, modify it, share it, for personal or commercial work alike.