A smooth, eased custom cursor overlay for Windows. Replaces your system cursor with a clean arrow sprite that lerp-eases toward your pointer at every frame, giving motion a polished, weighted feel.
At startup the app queries the primary monitor's current refresh rate and runs the frame loop at exactly that speed — 60, 120, 144, 240 Hz, or whatever the display is set to. No manual configuration needed.
The easing constant is per-frame, not per-second, so it must scale with refresh rate. The formula:
ease = 1 − (1 − EASE_BASE) ^ (60 / fps)
At 60 Hz: ease = 0.16. At 120 Hz: ease ≈ 0.084. At 240 Hz: ease ≈ 0.043. The cursor always takes the same real-world time to settle regardless of refresh rate.
Every frame the rendered cursor position moves a fraction of the remaining distance to the real pointer:
cursorX += (mouseX - cursorX) × EASE
cursorY += (mouseY - cursorY) × EASE
This is linear interpolation (lerp). The result is an ease-out that feels silky: it accelerates instantly and decelerates naturally as it converges. A snap threshold (SNAP = 0.04 px) prevents infinite sub-pixel drift.
On mouse-down the sprite grows from 32 × 32 px to 43 × 43 px instantly. 300 ms after mouse-up it shrinks back.
Refresh rate is read via EnumDisplaySettingsW → dmDisplayFrequency. The overlay is a tkinter borderless window with WS_EX_TRANSPARENT | WS_EX_LAYERED so clicks pass through. The system cursor is hidden via ShowCursor(False). Chroma-key (#FF00FF) makes the window background transparent.
CleanCursor is designed to have a negligible footprint. Here is what it actually costs to run.
The core work per frame is two lerp operations (four float additions/multiplications) plus one Win32 GetCursorPos call and one window move. The lerp math alone accounts for less than 0.05% of a single CPU core even at 360 Hz — it is arithmetically cheaper than a single frame of a video game's physics engine doing anything meaningful.
The total measured CPU usage (Python runtime + tkinter event loop + window management) sits around 0.1–0.5% of one core at 60 Hz under Task Manager, rising proportionally at higher refresh rates but remaining well under 1% in all real-world cases. The thread spends the overwhelming majority of its time sleeping between frames — the OS scheduler wakes it at the next interval and immediately returns it to sleep.
None. The overlay is a plain Win32 window moved by the CPU each frame. No draw calls, no compositor involvement beyond what Windows already does for any window, no shaders.
Approximately 30–50 MB for the bundled Python runtime, tkinter, and Pillow. The two cursor sprites (32 × 32 and 43 × 43 px) are under 10 KB of image data combined. The memory footprint is fixed at startup and does not grow over time.
None introduced. The overlay window carries WS_EX_TRANSPARENT, which means Windows treats it as invisible for hit-testing — all mouse events fall straight through to whatever is underneath. The easing effect is purely visual: the real cursor position (used by every other application) is always exactly where your hardware puts it.
The refresh rate is detected once at launch via a single EnumDisplaySettingsW call. There is no background scanning, no polling of hardware sensors, and no network activity of any kind.
| Resource | Cost |
|---|---|
| CPU (lerp math only) | < 0.05% of one core @ 360 Hz |
| CPU (total, typical) | < 0.5% of one core |
| GPU | 0% |
| RAM | ~30–50 MB (Python runtime) |
| Input lag added | 0 ms |
| Network | None |
- Python 3.10+
- Pillow (
pip install Pillow) - PyInstaller (
pip install pyinstaller)
build.batProduces dist\MysterioCursor.exe. Double-click to run. Press Escape to restore your cursor and exit.
python cursor_app.py| Constant | Default | Effect |
|---|---|---|
EASE_BASE |
0.16 |
Lerp strength calibrated at 60 fps — scaled automatically |
SIZE_IDLE |
32 |
Normal cursor size in px |
SIZE_CLICK |
43 |
Cursor size on click |
SNAP |
0.04 |
Sub-pixel snap threshold in px |
CLICK_SHRINK_MS |
300 |
Ms after mouse-up before cursor returns to idle size |
CleanCursor/
├── cursor_app.py # Windows overlay (tkinter + ctypes)
├── build.bat # Build script → dist\MysterioCursor.exe
├── requirements.txt
└── LICENSE
MIT — see LICENSE.