A raster image editor for Windows, written twice: once as a single HTML file inside Electron, once natively in C# 12 with WPF and SkiaSharp. Both are developed side by side, and a rule found on one side is carried to the other.
Try it in your browser → · Download for Windows · Русская версия этого файла
The interface is in Russian only, in both versions. The browser demo is the fastest way to see whether the thing is any good.
| Electron | C# | |
|---|---|---|
| Folder | paint-pro-electron/ |
src/, tests/ |
| Stack | one HTML file, canvas, vanilla JS; Electron adds the window, menu and file dialogs | C# 12, WPF, .NET 8, SkiaSharp, MVVM, Command pattern |
| Builds | installer, portable, and a single .html that runs offline in any browser |
installer and a self-contained single .exe |
| Version | 1.20.0 | 1.36.0 |
| Tests | 469 Playwright checks in Chromium + 17 against the real app | 1144 xUnit tests, including two fuzzers |
| Docs | README, architecture | README (русский) |
Both have nineteen tools (freehand, fill and eyedropper, text, eight shapes, rectangular and four-point selection, crop, hand), layers with opacity, five themes, a floating object you can drag, resize and rotate, and a history where any single edit in the middle can be switched off and the document is rebuilt without it.
The Electron version came first. The C# one started as a port with a cleaner architecture: layers, MVVM, commands with diff bitmaps for undo, one mode enum instead of a pile of flags. Since then they have been kept equal in features, and most of the rules in either codebase were found on the other side. paint-pro-electron/tests/parity.spec.js is named after exactly that: each check carries the release that discovered the rule in C#.
Neither suite is a set of unit tests around functions. The Electron checks open the page in Chromium, move the real mouse over the canvas and read pixels back. The C# tests drive real WPF elements on an STA thread, read MainWindow.xaml to check every binding and hotkey, and fuzz the history tape with random edit sequences. The strongest invariant, in both, is that the cursor position in the history alone determines the document, whatever path led there.
CHANGELOG.md (in Russian) tells every release with its reasoning. Most entries start with what a test or a sweep found, not with what was planned.
No picture here was taken from the screen. paint-pro-electron/tools/make-screenshots.js launches the real app through Playwright and draws with real mouse movements. tools/PaintPro.Screenshots opens the real WPF window far off screen, draws with the real tools through the same path the mouse takes, and renders the window itself. The very first C# frames found two bugs, fixed in 1.27.0: half the tool icons stayed white in the light theme, and the default light-grey scrollbars cut across the dark glass.
Each release carries the builds of both versions. Up to 1.15.0 only the Electron version was published here and the tags followed its numbers; from 1.27.0 the tag follows the C# number and the Electron version is in the release title and the file names.
Windows 10 or 11, x64. The binaries are not code-signed, so SmartScreen warns on first run.
# Electron
cd paint-pro-electron; npm install; npm start
# C#
dotnet run --project src/PaintPro.Wpf -c Release
dotnet test tests/PaintPro.TestsPackaging steps for both are in their READMEs.
MIT, see LICENSE.