P1Xel Editor

A portable pixel editor custom-built for Game Boy (Color) development — from the first tile to a running ROM in one tiny executable.

~2.4 MiB single EXE (free "floppy" edition: ~720 KiB UPX-packed) · no installer · no runtime dependencies · Windows 10+ · native Linux (GTK2) build from the same source

Written in Free Pascal with Lazarus LCL.

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Screenshots

Features

Editors & modes

Editor	What you get
Tile Editor	8×8 indexed 2bpp painting — draw, fill, line, clear; grid toggle, zoom, right-click color-0 erase; Single ⇄ 2×2 meta-tile modes (picking a named asset switches the view automatically)
Painter mode	Paint an arbitrary block of tiles as one image, then stamp it anywhere on the map — whole-stamp flipping included
Sprite Editor	128-tile sprite zone; up to 40 sprites per screen; multi-part meta-sprites with positioned parts; hardware-ready OAM export
Font Editor + Manager	81-glyph font with its own manager — edit glyphs, browse the map, and bake text directly onto screens with the text tool
Screen Designer	Place tiles and meta-tile stamps, bake text, place sprites, and paint per-cell attributes (palette index + H/V flips)
Inspect tool	Click any cell — see the tile's name, whether it is single or meta, and which sprite covers it
Screen Manager	Add, rename, delete screens in 20×18 and 32×32 sizes, up to 255 levels
Art Windows	20×18 fullscreen art editor — dedicated windows for title-screen art, each bound to its own ROM bank (up to 16 banks × 192 tiles), with a per-window bank selector and a 1× native proofer
Whole-ROM viewer	Every byte of your ROM shown as tiles — sprite zone, font, background, and the raw tail — zoomable
Screen Proofer	Engine-accurate preview of any screen: verify the map, attributes, and sprites before you build

Color

• 8 BG + 8 OBJ CGB palette banks, 4 colors each — edited visually, exported as hardware RGB555

Naming & the data contract

• Name everything — tiles, meta-tiles, sprites, meta-sprites — with duplicate detection and tags (solid, lethal, custom)
• Names flow straight into catalog.toml; exports use standard Game Boy layouts any engine can consume:

meta.dat      level table, palette RAM dumps, level descriptors (v2: + art window table — only when banks exist)
tileset.chr   6144-byte 2bpp tileset (sprites · font · background zones)
bank<k>.chr   art bank dumps — up to 16 × 192 tiles, VRAM bank 1 (only when banks exist)
levels.tlm    tile maps + CGB attribute planes
art.tlm       fullscreen art window records — bank-relative tiles, attribute bit 3 set (only when banks exist)
levels.oam    hardware OAM entries per level
catalog.toml  every named asset with map bytes and tags (+ [banks], [art_windows])
banks.rgbasm  generated bank ROMX sections with size asserts — assembled into the ROM by Build ROM

Projects without art banks export the byte-identical v1 contract — old projects are unaffected. The engine-side bank contract (file layouts, ArtBank<K>Data labels, CGB load recipe) is documented in docs/CONTRACT-BANKS.md: the ROM carries the bank data, ready for engine consumption.

• PNG export at 100% and 400% — any tile, meta-tile, sprite, screen, or the whole ROM

Toolchain — zero to running ROM

• Setup wizard: downloads and installs the RGBDS assembler (pinned release, SHA-256-verified), the BGB emulator, and the nomad-core sample project — staged safely, nothing touched on failure
• One-click Build ROM (rgbasm → rgblink → rgbfix) with live output and the failing file/line in the build log
• Bank-aware ROM builds — art banks ship in the ROM as generated banks.rgbasm ROMX sections, byte-verified at link time
• Run in emulator — or watch mode that rebuilds and reloads while you edit
• Tool URLs overridable via tools/toolchain.ini

Projects that don't lose work

• Binary .p1x project format (version 3 — v1/v2 files still open) with atomic saves (write temp → flush → replace)
• Autosave every 10 seconds with crash recovery prompt on next launch
• 20-level undo/redo, dirty-state guards on open/close, recent projects, command-line open

Shareware build

The same editor with a 5-second purchase reminder at startup — build mode Release-Shareware (-dSHAREWARE). Buy URL defaults to the product page and is overridable via [Shareware] BuyUrl in tools/toolchain.ini.

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Build

Toolchain: Lazarus 4.x + FPC 3.2.2 (lazbuild).

# Windows (from the repo root)
build.cmd Debug              # or: Release (sold build, unpacked + signed), Release-Shareware (floppy build, UPX)
powershell -File tests\run_all.ps1   # every automated gate in one go

# Linux (GTK2, x64) — build in a native FS, never on a mounted Windows drive
lazbuild --build-mode=Linux main.lpi

Output lands in builds/. The Linux mode expects LCLWidgetType=gtk2 (default in main.lpi).

Test

Pure-FPC console tests under tests/ — no GUI needed:

fpc -Mobjfpc -Sh tests/loader_compile_test.pas   # project loader vectors (v1/v2/sample)
fpc -Mobjfpc -Sh tests/sha256_test.pas           # FIPS vectors + pinned rgbds artifacts
cd tests && fpc -Mobjfpc -Sh -Fu.. export_harness.lpr   # .p1x -> 5-file export harness
powershell -File tests/run_golden_gate.ps1       # byte-compare exports vs tests/fixtures/
python tests/zipslip/run_matrix.py               # zip-slip guard regression matrix

Release packaging

powershell -ExecutionPolicy Bypass -File scripts/package_release.ps1

Runs tests/run_all.ps1 first (red gate = no release), then builds Release (unpacked, Authenticode-signed before zipping) + Release-Shareware (UPX, unsigned), produces dist/ with portable zips (EXE + EULA + notices), the Inno Setup installer (when Inno 6/7 is installed), a *-symbols-win32.zip with the .dbg for crash symbolization (keep, do not publish), and SHA256SUMS.txt. Signing: scripts/sign.cmd (cert thumbprint or Azure Trusted Signing; -RequireSigning refuses to produce unsigned artifacts).

Repository layout

main.lpr / main.lpi        project entry + build modes (Debug/Release/Release-Shareware/Linux)
main_window.pas/.lfm       the editor (tile/sprite/font hosts, screens, toolchain UI)
engine_export.pas          the data-contract exporters (deterministic, golden-testable)
project_io.pas             pure-FPC .p1x loader
downloader.pas             WinInet (Windows) / fphttpclient (Linux) + zip/tar extraction + SHA-256
wizard.pas                 toolchain setup wizard (pins, staging, TOFU)
sha256.pas                 pure-Pascal FIPS 180-4
nag_form.*                 shareware reminder ({$IFDEF SHAREWARE})
installer/  scripts/       Inno Setup script, packaging + signing
tests/                     console tests, golden gate, regression kits
docs/CONTRACT-BANKS.md    engine-side art bank contract (bank<k>.chr · art.tlm · meta.dat v2 · banks.rgbasm)
shopify/                   storefront templates

License & notices

The application is distributed under its end-user license — see EULA.md. It is built with Free Pascal / Lazarus LCL (modified LGPL — see THIRD_PARTY_NOTICES.md), the free "floppy" edition is packed with UPX (GPL + special exception), and it integrates RGBDS (MIT) and BGB (freeware) at runtime.

P1Xel Editor is not affiliated with, endorsed by, or sponsored by Nintendo. Game Boy is a trademark of Nintendo.

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Made in Poland by Cyfrowy Nomada · Fits on a floppy.