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Turn your idle screen into an infinite journey through the Mandelbrot set.
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FractalSaver is a free Windows screen saver that renders the Mandelbrot set in real time, continuously zooming into 100 hand-picked locations across 15 categories — from Seahorse Valleys and Spiral Galaxies to Misiurewicz Points and Mini Mandelbrot Copies.
Every run is unique. The visit order is shuffled, zoom targets are randomly offset, and colors shift continuously, so you'll never see the same animation twice.
- GPU mode: D3D11 Compute Shader with double-float emulation (~48-bit precision)
- CPU fallback: AVX2 SIMD (4-lane double), multi-threaded — works on any PC without a dedicated GPU
- 6 color themes: Red, Green, Blue, Cyan, Magenta, Gold — shuffled randomly each run
- 4 coloring styles: Smooth Gradient, Contour Bands, Stripe Average, Triangle Inequality Average (TIA)
- 24 visual combinations: 6 themes x 4 styles, all shuffled for maximum variety
- Auto color cycling: colors rotate every frame for endlessly shifting palettes
- 2x2 supersampled anti-aliasing: silky smooth edges at every zoom level
- Up to 16,384x zoom: deep dives into fractal structure with double-float precision
- 100 interesting locations in 15 categories — never boring
- Boundary tracking: the camera automatically follows the most visually complex edges
- Adaptive redirect: mid-zoom direction changes seek out nearby intricate patterns
- Curvature filtering: flat, featureless boundaries are automatically skipped
- Automatic primary selection: renders on the largest monitor, mirrors to all others with aspect-ratio-preserving center crop
- Secondary monitors: lightweight mirror windows with input handling, cursor hiding, and 2-second grace period
- Emulation mode:
/emu(dual) or/emu:N(N=2~4) for testing multi-monitor layouts on a single display
- System info overlay: GPU/CPU model, RAM, resolution, FPS, zoom level, iteration count — readable on any background with double-outline rendering
- 7-segment digital clock: bouncing LED-style display with premultiplied alpha blending
- Single binary: installer + screen saver combined — extension-based mode detection (.exe=install, .scr=screensaver)
- AV-friendly: no RCDATA embedding (dropper pattern), uses CopyFileW(self) instead
- Single file (~453 KB .exe) — no runtime dependencies, no .NET, no Java
- Static CRT (/MT) — runs on a clean Windows install
- Built-in installer — auto UAC elevation, no separate installer needed
- Zero external dependencies — everything is built from scratch in C++20
| Component | Minimum |
|---|---|
| OS | Windows 10 / 11 (64-bit) |
| CPU | Intel Haswell (2013+) or AMD Excavator (2015+) with AVX2 |
| GPU | Any DirectX 11 capable GPU (optional — CPU fallback available) |
| RAM | 64 MB free |
| Disk | < 1 MB |
- Download
FractalSaver.exe(orFractalSaverLite.exefor older PCs) - Double-click to run — UAC will auto-elevate and install the screen saver
- The Screen Saver Settings dialog opens automatically
To preview without installing: FractalSaver.exe /s
To uninstall: FractalSaver.exe /u or use Windows standard uninstaller
| Setting | Options | Default |
|---|---|---|
| Rendering | GPU (auto) / Force CPU | GPU auto |
| Zoom Speed | 1 (slow) ~ 10 (fast) | 3 |
| Color Style | Auto Cycle / Smooth / Contour / Stripe / TIA | Auto Cycle |
| Info Overlay | On / Off | On |
| Digital Clock | On / Off | Off |
- C++20 with MSVC Build Tools 2022
- D3D11 Compute Shader (cs_5_0) with
precisekeyword and IEEE strictness for numerical accuracy - AVX2 intrinsics (
__m256d) — 4 pixels computed simultaneously - Double-float emulation on GPU: Dekker splitting for ~48-bit mantissa precision
- Cardioid/Period-2 bulb early rejection — SIMD-accelerated, skips most interior points without iteration
- One-pass row rendering with stack-allocated buffers (~40 KB in L1 cache vs. 132 MB heap)
- Exponential zoom with adaptive panning and boundary-aware target tracking
- Binary search boundary detection (30~50 iterations, precision ~10^-9 to ~10^-15)
- PCA-based curvature analysis to filter out visually uninteresting boundaries
- Whole Program Optimization (/GL + /LTCG) and Link-Time Code Generation
FractalSaver computes the classic Mandelbrot iteration z = z² + c for every pixel, with several enhancements:
- Smooth iteration count:
n + 1 - log₂(log₂(|z|))eliminates color banding - Cosine palette: Inigo Quilez-style color generation with per-channel phase offsets
- Orbit traps (Stripe/TIA): accumulate angular and radial orbit statistics for rich texturing
- Interior coloring: average orbit magnitude creates pseudo-iteration values for non-escaping points
- Dynamic max iterations:
100 + 50 × log₂(zoom), capped at 5000
| Edition | Description | Download |
|---|---|---|
| Full | Native resolution, uncapped FPS | FractalSaver.exe |
| Lite | Half resolution, 30 fps cap — for older PCs | FractalSaverLite.exe |
If you enjoy FractalSaver, consider supporting its development:
Yongho Hwang (@jogakdal)
- Email: jogakdal@gmail.com / jogakdal@naver.com
- Blog (Velog): https://velog.io/@jogakdal
- Blog (Naver): https://blog.naver.com/jogakdal
All rights reserved. This software is provided as-is for personal use.
FractalSaver — Where mathematics meets art.