Fractalus WebGL Renderer

A high-performance WebGL-based fractal renderer supporting multiple fractal formulas, rotation, color cycling, and SVG export.

Supported Fractals

• Mandelbrot — classic z² + c escape-time fractal
• Burning Ship — uses absolute values: (|Re(z)| + i|Im(z)|)² + c
• Tricorn — conjugate variant: conj(z)² + c
• Julia — fixed c parameter, z starts at pixel position
• Phoenix — z² + Re(c) + Im(c)·z_{n-1} with memory of previous iteration
• Newton (z³−1) — Newton's method root-finding, colored by convergence

Features

• Multiple Fractal Types: Switch between 6 formulas via dropdown selector
• Rotation: Toggle auto-rotation with adjustable speed (0.1x–5.0x)
• WebGL Rendering: Hardware-accelerated fractal computation using GPU shaders
• Fullscreen Mode: Immersive full-screen exploration with F key toggle
• Intelligent Autopilot: Automatic exploration with smart navigation to interesting regions
• Mouse Wheel Navigation: Precise cursor-centered zooming
• Palette Control: Left/right mouse buttons for color palette stepping, hold for continuous cycling
• Color Cycling: Smooth automatic color transitions with adjustable speed
• SVG Export: Captures WebGL framebuffer as scalable SVG with metadata JSON
• Deep Linking: URL parameters for sharing specific views
• Mastodon Sharing: Client-side sharing via Web Intent with clipboard image copy and hashtags

Quick Start

Just open index.html in a browser, or serve the directory:

python3 -m http.server 8000
# Open http://localhost:8000

Interactive Controls

Navigation

• Mouse Wheel: Zoom in/out centered on cursor position
• Middle Mouse Drag: Pan around the fractal
• F Key: Toggle fullscreen
• Escape: Exit autopilot mode

Fractal Selection

• Fractal dropdown: Switch between formulas (view resets to optimal defaults per type)

Rotation

• 🔄 Rotation: Toggle auto-rotation on/off
• Speed slider: Adjust rotation speed (full revolution per 20s at 1.0x)

Color Palette

• Left Mouse Click: Step to previous palette (−25°)
• Right Mouse Click: Step to next palette (+25°)
• Hold Mouse: Continuously cycle through palettes
• Arrow Keys: Left/Right rotate colors (±15°), Shift for fine (±5°)
• R Key: Reset color palette

Autopilot

• 🚁 Start Autopilot: Automatic exploration with smart zoom, panning, and color changes
• Visits curated interesting locations (seahorse valleys, spiral areas, etc.)
• Smooth 2–5 second transitions, 2–8 second intervals
• Press Esc to stop

Screenshots & Sharing

• 📸 Take Screenshot: Save SVG + metadata JSON with file picker dialog
• 🐘 Share to Mastodon: Copy image to clipboard, open Mastodon with pre-filled post text and hashtags

URL Parameters

• type — fractal type (0=Mandelbrot, 1=Burning Ship, 2=Tricorn, 3=Julia, 4=Phoenix, 5=Newton)
• cx, cy — center coordinates
• z — zoom level
• iter — max iterations
• offset, scale — color palette parameters
• rot — rotation angle (radians)
• jcx, jcy — Julia set c parameter
• palette — named preset (default, fire, ocean, neon, pastel)

Technical Details

WebGL Shaders

• Single fragment shader with branching for all 6 fractal formulas
• Coordinate rotation via uniform angle applied before iteration
• Newton fractal uses convergence-based coloring (root detection via atan)
• Complex arithmetic helpers (complexMul, complexDiv) for Newton's method
• HSV to RGB conversion for vibrant color generation

SVG Generation

• Reads WebGL framebuffer pixel data
• Groups pixels by color and merges adjacent pixels into rectangles
• Includes fractal name and timestamps in SVG metadata

Browser Requirements

• WebGL support
• ES6 JavaScript support

Installation

Debian/Ubuntu

Packages are available. Please use the repo:

wget -qO- https://repo.vitexsoftware.com/KEY.gpg | sudo tee /etc/apt/trusted.gpg.d/vitexsoftware.gpg
echo "deb [signed-by=/etc/apt/trusted.gpg.d/vitexsoftware.gpg]  https://repo.vitexsoftware.com  $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/vitexsoftware.list
sudo apt update
sudo apt install fractalus

The installed package serves the app via Apache at /fractalus and provides a fractalus launcher command.

Building from Source

dpkg-buildpackage -us -uc -b

Enjoy exploring the infinite complexity of fractals!