FastPreview — High-Performance Content Rendering for Java [v0.1.0]

Lightweight native rendering capabilities for PDF, HTML, Code, Text, Markdown, and SVG.

FastPreview provides high-speed content rasterization for Java applications. It delivers off-heap pixel buffers directly to FastImage, bypassing the overhead of traditional UI frameworks.

// Quick Start — Render a PDF page to FastImage
import fastpreview.api.FastPreview;
import fastpreview.api.PreviewRequest;
import fastpreview.api.PreviewResult;

public class Demo {
    public static void main(String[] args) {
        FastPreview api = new FastPreview();
        PreviewRequest request = new PreviewRequest(new File("document.pdf"), 800, 600);
        
        PreviewResult result = api.render(request);
        
        if (result.isSuccess()) {
            System.out.println("Rendered in " + (result.getRenderTimeNanos() / 1_000_000.0) + " ms");
        }
    }
}

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Table of Contents

• Key Features
• Architecture
• Installation
• Try the Demo
• Backends
• Platform Support
• Building from Source
• License
• Related Projects

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Key Features

• 🚀 Native Performance — Direct integration with PDFium, WebView2, and Skia.
• ⚡ Zero-Copy — Off-heap pixel buffers delivered directly to FastImage.
• 📦 Modular Backends — Pluggable support for PDF, HTML, Markdown, and more.
• 🎯 Deterministic — Predictable rendering times for batch processing.

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Architecture

FastPreview follows a strict pipeline: Content → Layout → Rasterization → PixelBuffer → FastImage

For more details, see ARCHITECTURE.md.

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Installation

FastJava modules require two dependencies: the module itself, and FastCore.

Maven (JitPack)

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

<dependencies>
    <!-- 1. FastPreview Module -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>fastpreview</artifactId>
        <version>0.1.0</version>
    </dependency>
    
    <!-- 2. FastCore (Required for native loading) -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>fastcore</artifactId>
        <version>0.1.0</version>
    </dependency>
</dependencies>

Gradle (JitPack)

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

dependencies {
    implementation 'com.github.andrestubbe:fastpreview:0.1.0'
    implementation 'com.github.andrestubbe:fastcore:0.1.0'
}

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Try the Demo

1. Clone this repository
2. Run run-demo.bat
3. Or navigate to examples/DemoPDF and run mvn exec:java

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Backends

Content Type	Backend	Status
PDF	PDFium	🚧 Integrating
HTML	WebView2	🚧 Integrating
Code	Syntax + FastTheme	✅ Skeleton
Text	DirectWrite	🚧 Planned
Markdown	Custom AST Renderer	🚧 Planned
SVG	Skia	🚧 Planned

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Platform Support

Platform	Status
Windows 10/11 (x64)	✅ Fully Supported
Linux	🚧 Planned
macOS	🚧 Planned

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Building from Source

For detailed instructions on compiling the C++ JNI code and building the Maven FatJAR, see COMPILE.md.

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License

MIT License — See LICENSE file for details.

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Related Projects

• FastImage — High-performance image processing
• FastCore — Native Library Loader for Java
• FastTheme — Unified styling and colors

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Made with ⚡ by Andre Stubbe