Rounder for Windows

Rounder for Windows is a tray utility that draws modern rounded-corner cutouts on selected displays.

This Windows port tracks the macOS Rounder v2.1.4 feature set where the platform allows it: immediate overlay updates, selectable monitors, presets, rounded/squircle/polygon cutouts, login startup, and the Super Duper Gaming Mode with animated rainbow edge glow.

Japanese README

Features

• Runs quietly from the Windows notification area.
• Left-click or double-click the tray icon to open settings.
• Toggle the rounded-corner effect from the tray menu.
• Apply changes immediately without restarting the app.
• Select target monitors. Newly connected monitors are covered automatically.
• Choose rounded, squircle, or polygon cutout shapes.
• Adjust radius, color, visible corners, gaming speed, glow intensity, and bloom width.
• Save, edit, import, and export presets.
• Launch at login using the current user's Windows Run registry key.
• Keeps overlay windows above the taskbar by reasserting topmost z-order.
• Per-monitor DPI aware for mixed-scale environments.

Requirements

• Windows 10 or Windows 11
• .NET 9.0 Desktop Runtime
• .NET 9.0 SDK if building from source

Build

dotnet build .\Rounder_Windows.csproj -c Release

Single-file Release Build

dotnet publish .\Rounder_Windows.csproj -c Release -r win-x64 --self-contained true -p:PublishSingleFile=true -p:EnableCompressionInSingleFile=true -p:IncludeNativeLibrariesForSelfExtract=true -p:DebugType=None -p:DebugSymbols=false -o .\artifacts\release\Rounder_Windows-win-x64-singlefile

The release executable is:

artifacts\release\Rounder_Windows-win-x64-singlefile\Rounder_Windows.exe

Installer Build

Install Inno Setup 6, then run:

& "${env:ProgramFiles(x86)}\Inno Setup 6\ISCC.exe" `
  "/DMyAppVersion=2.1.5" `
  "/DPublishDir=$PWD\artifacts\release\Rounder_Windows-win-x64-singlefile" `
  ".\installer\Rounder_Windows.iss"

The installer is:

artifacts\installer\Rounder_Windows_Setup.exe

GitHub Actions Release

The Build and Release workflow builds the pushed commit on Windows. Pushes to main or master upload workflow artifacts, and automatically publish a v<Version> GitHub Release (with auto-generated notes) the first time the .csproj <Version> lands without a matching release — bump the version and push to release. Each release includes:

• Rounder_Windows.exe
• Rounder_Windows-win-x64-singlefile.zip
• Rounder_Windows_Setup.exe

Pushing a v* tag manually (or dispatching the workflow with a tag name) triggers the same release flow:

git tag v2.1.5
git push origin v2.1.5

Implementation Notes

• Target framework: .NET 9, net9.0-windows
• Tray/app lifetime: Windows Forms ApplicationContext and NotifyIcon
• Settings UI: WPF with iNKORE.UI.WPF.Modern Fluent styles, Mica backdrop, and a macOS-style sidebar with continuous settings scroll
• Overlay drawing: click-through topmost layered WinForms windows with per-pixel alpha
• Gaming glow: separate transparent edge-band layered windows with animated rainbow gradients
• Startup: HKCU\Software\Microsoft\Windows\CurrentVersion\Run
• Settings storage: JSON under %AppData%\Rounder

Troubleshooting

The corners are not visible.
Check that Rounder is enabled and that the target display is selected.

The overlay is hidden behind system UI.
Rounder reasserts topmost z-order, but secure desktops, lock screen, and exclusive fullscreen apps can still appear above normal app windows.

The build fails because Rounder_Windows.exe is locked.
Exit the running app from the tray menu, or stop the Rounder_Windows process, then build again.