FastStylus 0.1.0 [ALPHA-2026-05-23] — Ultra-Fast Native Windows Stylus & Pen Input Engine for Java

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⚡ High-speed Win32 WM_POINTER stylus digitizer interception, pressure tracking, tilt angles, and eraser detection for Java.

FastStylus provides hardware-level stylus and pen access directly from the Win32 Pointer API (WM_POINTER), bypassing the single-cursor mouse emulation limitations of standard AWT and Swing. Capture 10-bit raw pressure (0..1024), dual-axis tilt angles (-90°..+90°), continuous rotation, barrel buttons, and hardware eraser state with minimal latency.

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Quick Start

import faststylus.FastStylus;
import javax.swing.JFrame;

public class Demo {
    public static void main(String[] args) {
        JFrame frame = new JFrame("FastStylus Demo");
        frame.setSize(1280, 800);
        frame.setVisible(true);

        // 1. Initialize native stylus interception on the target window
        FastStylus stylus = FastStylus.create(frame);

        // 2. Add real-time stylus listener
        stylus.addListener(event -> {
            System.out.printf("[STYLUS] ID=%d Pos=(%d,%d) Pressure=%d%% Tilt=(%d,%d) Eraser=%s Phase=%s\n",
                event.id, event.x, event.y, event.pressurePercent, event.tiltX, event.tiltY, event.isEraser, event.state);
        });

        // 3. Start background polling thread (~120 Hz)
        stylus.start();
    }
}

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Table of Contents

• Quick Start
• Why FastStylus?
• Key Features
• Real-World Use Cases
• Performance Benchmarks
• API Quick Reference
• Technical Demos & Benchmarks
• Installation
• Documentation
• Platform Support
• Related Projects
• License

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Why FastStylus?

Standard Java input subsystems (AWT MouseListener, JavaFX, Swing) treat digitizers and pens as generic single-cursor mouse emulations:

1. Single-Cursor Emulation: Standard AWT discards pen pressure, tilt angles, and barrel button modifiers, treating active digitizers as blunt mice.
2. Missing Sensor Geometry: Physical force levels (0..1024), dual-axis tilt (-90°..+90°), and barrel rotation (0..360°) are completely lost in pure Java.
3. Event Queue Delays: Synthesized mouse events pass through the Event Dispatch Thread (EDT), creating noticeable stroke lag during drawing or handwriting.
4. Legacy Driver Lock-In: Alternative solutions rely on deprecated 1990s Wintab 32-bit DLLs that fail on modern Windows Ink devices and Microsoft Surface hardware.

FastStylus bridges directly to the modern Win32 WM_POINTER digitizer subsystem:

• Hardware Pressure & Tilt: Full 0–1024 raw pressure levels (mapped to 0–100%) and continuous dual-axis tilt tracking.
• Eraser & Invert Sensing: Automatic detection when the stylus is physically flipped to the eraser end.
• Sub-Millisecond Event Loop: Direct window subclassing captures digitizer messages before JVM event queue scheduling.
• Universal Hardware Support: Native out-of-the-box support for Windows Ink, Microsoft Surface, and Wacom AES/EMR digitizers.

Feature	Java AWT / Swing	Legacy Wintab Wrappers	FastStylus
Input Subsystem	Synthesized WM_MOUSEMOVE	Legacy Wintab DLL (Wacom only)	Native Win32 WM_POINTER
Pressure Tracking	❌ Binary click only (0/1)	⚠️ Driver-dependent	✅ 10-bit raw resolution (0–1024)
Tilt & Rotation	❌ Discarded	⚠️ Inconsistent support	✅ Dual-axis (±90°) + 360° rotation
Eraser / Invert Detection	❌ None	⚠️ Unreliable	✅ Native hardware tip inversion
Event Dispatch Latency	15–30 ms (EDT queue lag)	5–15 ms	< 0.1 ms (Direct window subclassing)
Device Compatibility	Generic mouse fallback	Wacom desktop tablets only	Surface, Windows Ink, Wacom AES/EMR

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Key Features

• 🖊️ Hardware Pressure Tracking — Full 10-bit raw resolution (0–1024 levels, normalized 0–100%).
• 📐 Dual-Axis Tilt & Rotation — Precise X/Y tilt angles (-90° to +90°) and continuous 360° barrel rotation.
• 🔄 Automatic Eraser & Invert Detection — Native recognition of inverted pens and hardware eraser tips.
• 🔘 Dual Barrel Buttons — Instant detection of barrel side switches (BTN1, BTN2).
• 🛸 Proximity Hover Sensing — Track cursor coordinates while the pen hovers above the screen without contact.
• ⚡ Zero-Copy JNI Architecture — Continuous event dispatch with zero garbage collection churn.

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🖊️ Compatible Devices

• Microsoft Surface Pro 8/9, Studio, Go, Laptop (with Surface Pen)
• Wacom Penabled, AES, and EMR devices
• Windows Ink compatible pens
• HP, Dell, Lenovo 2-in-1 devices with active pens

✅ Tested Devices

Device	Pen	Pressure	Tilt	Eraser	Barrel	Status
Surface Pro 8	Wacom Bamboo Ink Plus	✅ 0-1024	✅ ±90°	✅	✅ 2 buttons	✅ Verified Apr 2026

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Performance Benchmarks

FastStylus is measured using JMH (Java Microbenchmark Harness) to ensure zero-overhead event processing:

Benchmark / Operation	Score (ops/ms)	Ops per Second
benchmarkStylusEventAllocation	~19,400 ops/ms	> 19.4 Million
benchmarkStylusEventFormatting	~1,520 ops/ms	> 1.52 Million
Native Polling Loop Rate	~120 Hz	Smooth Real-time Tracking

Measured on Windows 11 (x64), JDK 21+.

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API Quick Reference

Method	Return Type	Description	Docs
FastStylus.create(frame)	FastStylus	Resolves window HWND and installs native WM_POINTER subclass hook.	Reference
addListener(listener)	void	Registers a callback for real-time stylus event dispatch.	Reference
removeListener(listener)	void	Unregisters a previously registered stylus listener.	Reference
start()	void	Launches the dedicated background stylus polling thread (~120 Hz).	Reference
stop()	void	Halts the background stylus polling loop.	Reference
FastStylus.isStylusAvailable()	boolean	Queries if a physical stylus or active digitizer is present.	Reference
FastStylus.getMaxStylusPoints()	int	Returns maximum simultaneous pens supported by hardware.	Reference

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Technical Demos & Benchmarks

Case	Java Example	Launcher	Description
Interactive Pen HUD & Canvas	Demo.java	run-demo.bat	Real-time drawing canvas with pressure-width scaling, tilt circle HUD, and eraser mode.
JMH Microbenchmark Suite	Benchmark.java	run-benchmark.bat	Microbenchmark suite profiling stylus event allocation and formatting throughput.

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Installation

Option 1: Maven (Recommended)

Add the JitPack repository and the dependency to your pom.xml:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

<dependencies>
    <!-- FastStylus Library -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>FastStylus</artifactId>
        <version>0.1.0</version>
    </dependency>
    <!-- Required Native JNI loader -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>FastCore</artifactId>
        <version>0.1.0</version>
    </dependency>
</dependencies>

Option 2: Gradle (via JitPack)

repositories {
    maven { url 'https://jitpack.io' }
}

dependencies {
    implementation 'com.github.andrestubbe:FastStylus:0.1.0'
    implementation 'com.github.andrestubbe:FastCore:0.1.0'
}

Option 3: Direct Download (No Build Tool)

Download the latest JARs directly to add them to your classpath:

1. 📦 FastStylus-0.1.0.jar (The Core Library with embedded native DLL)
2. ⚙️ fastcore-0.1.0.jar (The Mandatory Native Loader)

Important

All JARs must be in your classpath for the JNI calls to function correctly.

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Documentation

• COMPILE.md: Full compilation guide (MSVC C++17 build chain + JNI Setup).
• REFERENCE.md: Comprehensive API specification, event fields, and hook lifecycle.
• PHILOSOPHY.md: The engineering rationale for hardware-native pen interception.
• ROADMAP.md: Planned milestone features and performance extensions.
• CHANGELOG.md: Complete version history and release notes.

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Platform Support

Platform	Architecture	Status	Driver / Subsystem
Windows 10 / 11	x64	✅ Fully Supported	Native Win32 WM_POINTER Subsystem
Linux	x64 / AArch64	🚧 Planned	libinput / evdev Stylus Tablet Tool Slots
macOS	Apple Silicon / x64	🚧 Planned	NSEvent & TabletProximity / CoreGraphics

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Related Projects

• FastCore — Native Library Loader & JNI Utilities for Java
• FastTouch — Native Multi-Touch Digitizer API for Java
• FastMouse — Ultra-Low Latency Native RawInput Mouse Engine
• FastKeyboard — Ultra-Fast Native RawInput Keyboard Engine
• FastHotkey — Low-Latency Global Hotkey API for Java
• FastVulkan — High-Performance Native Vulkan 2D Rendering Engine

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License

MIT License — See LICENSE file for details.

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Part of the FastJava Ecosystem — Making the JVM faster. 🚀