ProCraft

An open-source painting app for Android tablets, Windows and Linux, with its own Rust engine and GPU renderer: a Kotlin/Jetpack Compose UI on Android, the same interface in egui on the desktop.
Pressure-sensitive brushes, layers with blend modes, adjustments, selection and transform, animation and 3D painting, written from scratch.

_{From Releases: Android tablets take the .apk (or Obtainium, for updates); Windows the .msi installer or the portable .zip; Linux the .AppImage, the .deb or the .tar.gz (videos and PDFs there use the system's ffmpeg and poppler-utils).}

Painting · Layers & colour · Adjustments & transform · Actions · Planned features · Building

_{Dusk, painted from a blank canvas on a Lenovo Legion Tab: the brush library, the colour picker, the layers, a sun snapped round and filled, hills filled the same way, pines, stars with Bloom. About 1:20; the full video (MP4, 2:21) shows every menu at close to real speed. Every stroke is a pen stroke with pressure, eased in and out, played by the demo script.}

_{The canvas: the tools along the top, size and opacity in the sidebar, the whole screen for the painting.}

Painting

The brush library: eleven sets of our own brushes, each previewed with a stroke.

The Brush Studio: stroke path, stabilization, taper, shape, grain, rendering, wet mix, colour dynamics and more, tried out on the drawing pad.

Layers and colour

Layers with blend modes, opacity, alpha lock, clipping masks, masks and groups. Layers past what the GPU holds are kept compressed, so artworks with hundreds of layers open and paint smoothly.

Colour: disc, classic, harmony, value (with hex) and palettes.

Adjustments and transform

Hue, saturation, brightness on the sky layer, live. Also colour balance, curves, gradient map, blurs, noise, sharpen, bloom, glitch, halftone, chromatic aberration, liquify and clone, on the layer or painted on.

Transform: freeform, uniform, distort and warp, with snapping. Selection: automatic, freehand, rectangle and ellipse, with feather.

Actions

_{Actions: add files, photos and text; the canvas, its guides and assists; share as PNG, JPEG, PSD, PDF, TIFF, GIF or MP4; a time-lapse of every artwork; preferences and gesture controls.}

Planned features

ProCraft is in beta, on Android tablets and on the desktop (Windows and Linux).

Area	Status
Canvas: the top bar, the sidebar (size, opacity, modify, undo, redo), full screen, gestures (pinch, rotate, quick fit, two- and three-finger taps, scrub to clear)	✅
Brush engine: shape and grain sources, stroke path, stabilization, taper, rendering and glazes, wet mix, colour dynamics, pen pressure and tilt; the library and the Brush Studio	✅
Layers: blend modes, opacity, alpha lock, clipping masks, masks, groups, merge, the reference layer; large artworks kept compressed off the GPU	✅
Colour: disc, classic, harmony, value and palettes; history; eyedropper; filling by dragging the colour onto the canvas	✅
Adjustments, each with its toolbar, on the layer or painted on	✅
Selection (automatic, freehand, shapes, feather) and transform (freeform, uniform, distort, warp, snapping)	✅
Shapes that snap clean, drawing guides and drawing assist (2D, isometric, perspective, symmetry), text	✅
Animation and page assists, the reference window	✅
Gallery: stacks, new-canvas presets, import and share (PNG, JPEG, PSD, PDF, TIFF, GIF, MP4), time-lapse	🚧 nearly done
3D painting: OBJ and USDZ models, texture sets, painting on the mesh, lights and environments	🚧
Desktop: Windows and Linux, the same interface with a mouse, a pen tablet and keyboard shortcuts; an installer, an AppImage and a .deb	🚧 beta
Phones: their own app, ProCraft Pocket (this one is for tablets)	⬜

_{✅ works today · 🚧 in progress · ⬜ not started · 🚫 not planned}

Building Instructions

One Gradle command builds the whole app: it compiles the Rust engine with cargo-ndk and generates the Kotlin bindings.

• Clone this repository
• Make sure you have at least 6 GB of free disk space
• enter android and run ./gradlew assembleRelease -Pprocraft.abis=arm64-v8a, or open that folder in Android Studio and press Run.
• the desktop app: cargo run --release -p procraft-desktop from the repository's root; its installer and packages with packaging/windows/package.ps1 (WiX v5) and packaging/linux/package.sh (nfpm, appimagetool).

Build time dependencies:

required tools

    rustup, with the aarch64-linux-android and x86_64-linux-android targets
    cargo install cargo-ndk --version "^4" --locked
    Android SDK (API 37) and NDK 29.0.14206865
    JDK 17 or newer

cargo test --workspace runs the engine's and the renderer's tests on the desktop.

Path	What
crates/engine	document, brushes, stroke geometry, canvas view (no GPU)
crates/gpu	wgpu renderer: layers, strokes, compositing, display
crates/core	what both apps share above the renderer: the canvas session, every touch and gesture, the tools' state (adjustments, transform, selection, crop, Recolor) and which of them a button ends, the gallery, presets, gradients, time-lapse, the brush library's files, the layer menu, exports and their file names, and keyboard shortcuts; with the Android app's UniFFI bindings
android	the Android app (Gradle)
desktop	the desktop app (egui) for Windows and Linux
packaging	the desktop app's Windows installer and Linux packages, as the release workflow builds them

Builds are only tested on Windows 11.

License

MIT OR Apache-2.0, at your option.

• Third-party material: the Inter font, Lucide icons and the light panoramas the app bundles, and the libraries it's built with, are listed in NOTICE.
• Every asset, with its author, source and licence, is in ATTRIBUTION.md.
• Icons drawn using vector outlines (tools/icons/draw_icons.py, to the style guide).
• The demo painting, Dusk, is our own, made in the app.

Misc info for myself

Try to use semantic commit messages. Use feat: / fix: / chore: / docs: / etc.