lib_gerber_edit

A Rust library for manipulating RS-274X (Extended Gerber) and Excellon drill files, built on top of gerber-parser.

All lengths in the public API are in millimetres.

[dependencies]
lib_gerber_edit = "0.2"

---

Features

• Load a full PCB stackup from a folder or individual file readers
• Translate layers or a whole board by any offset
• Scale layers by independent X/Y factors (includes unit conversion)
• Merge two boards or layers of the same type
• Step-and-repeat — tile a pattern across a grid
• Bounding-box queries — with correct tool-width and arc accounting
• Vector text — render ASCII strings into a Gerber silkscreen layer with configurable size, line thickness, and horizontal/vertical alignment
• Error messages include the file name and line number of the failing layer

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Quick start

Panelise a board (2 × 1 grid)

use lib_gerber_edit::board::Board;
use lib_gerber_edit::{LayerCorners, LayerMerge, LayerTransform, Pos};
use std::path::Path;

let mut board = Board::from_folder(Path::new("gerbers/")).unwrap();
let size = board.get_size();

let mut copy = board.clone();
copy.transform(&Pos { x: size.width + 2.0, y: 0.0 }); // 2 mm gap

board.merge(&copy);
board.write_to_folder(Path::new("output/")).unwrap();

Render text onto a silkscreen layer

use lib_gerber_edit::board::Board;
use lib_gerber_edit::gerber_ascii::{AsciiText, HAlign, VAlign};
use lib_gerber_edit::layer::{Layer, LayerType};
use lib_gerber_edit::{LayerTransform, Pos};
use std::path::Path;

// Build a reusable format: 3 mm tall, centred on the origin.
let fmt = AsciiText::new(3.0)
    .h_align(HAlign::Center)
    .v_align(VAlign::Middle);

// Produce two layers from the same format object.
let rev_layer = fmt.build("Rev 1.0", LayerType::SilkScreenTop);

let mut board = Board::from_folder(Path::new("gerbers/")).unwrap();
board.add_layer(Layer {
    ty: LayerType::SilkScreenTop,
    name: "board.gto".to_string(),
    data: rev_layer.into(),
});
board.write_to_folder(Path::new("output/")).unwrap();

---

API overview

Core traits

Trait	Key method	Description
LayerCorners	get_corners() -> (Pos, Pos)	Axis-aligned bounding box (ink boundary, tool width included)
LayerCorners	get_size() -> Size	Width/height derived from get_corners
LayerTransform	transform(&Pos)	Translate all coordinates
LayerScale	scale(x, y)	Multiply X and Y coordinates independently
LayerMerge	merge(&Self)	Append another layer/board; aperture IDs are remapped
LayerStepAndRepeat	step_and_repeat(nx, ny, offset)	Grid replication

All traits are implemented for Board, GerberLayerData, ExcellonLayerData, and LayerData.

Board

Board::from_folder(path)          // load all recognised layers from a directory
Board::load(vec![("name.gbr", reader), ...]) // load from in-memory readers
board.add_layer(layer)            // merge if type exists, insert otherwise
board.get_layer(&LayerType::Top)  // look up a layer by type
board.write_to_folder(path)       // write all layers back to disk

GerberLayerData

GerberLayerData::empty(layer_type)          // blank layer ready for commands
GerberLayerData::from_type(ty, reader)      // parse with explicit type
GerberLayerData::from_commands(reader)      // infer type from FileAttribute
layer.write_to(&mut writer)                 // serialise to RS-274X

AsciiText

AsciiText::new(size_mm)           // character height in mm
    .ratio(0.8)                   // line thickness as fraction of size (default 1.0)
    .h_align(HAlign::Center)      // Left (default) | Center | Right
    .v_align(VAlign::Middle)      // Bottom (default) | Middle | Top
    .build("Hello", LayerType::SilkScreenTop)

The origin (0, 0) of the returned layer corresponds to the chosen alignment anchor.

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Supported layer types

Extension	LayerType
.gtl	Top
.gbl	Bottom
.glN	Inner(N)
.gts / .gbs	MaskTop / MaskBottom
.gto / .gbo	SilkScreenTop / SilkScreenBottom
.gtp / .gbp	PasteTop / PasteBottom
.gm1	Dimensions
.gm2	Milling
.gvc	VCut
.drd / .drl	Drill (Excellon)
.gbr	UndefinedGerber (type read from FileAttribute)

---

Notes

• Tested primarily with output from KiCad and Autodesk Eagle.
• Arc bounding boxes follow RS-274X §5.3 (multi-quadrant G75). Single-quadrant G74 arcs may have imprecise bounding boxes.
• The library is functional but still evolving — contributions welcome.

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Sample boards

Path	Source
test/mobo	opulo-inc/lumenpnp — CERN-OHL-W v2