Paint.NET 5.1.3

What's new in this version:

New:
- HlslUnaryFunctionEffect (for GPU effect plugin developers) now has FrexpMantissaPortion, FrexpExponentPortion, ModfIntegerPortion, and ModfFractionalPortion. These provide access to the Frexp and Modf HLSL instructions
- Plugins may now implement custom DirectWrite IInlineObjects
- IEffectConfigForm.Close() is now public, and may be used by plugins that are hosting other effects via IEffectsService2
- Added an accelerator key for Image -> Rotate 90° Counter-clockwise
- Added accelerator keys to the View menu for the Inches, Centimeters, and Pixels choices

Changed:
- Improved frame rate, frame pacing, and responsiveness of the canvas when using CPU- or GPU-intensive tools such as Move Selected Pixels
- Improved: The Color properties for the Clouds effect now have Reset buttons, which will reset them to the current Primary and Secondary colors
- Substantially improved UI responsiveness when modifying a complex selection with a combine mode other than Replac
- Reduced the performance cost of the circle "preview cursor" that all of the brush tools use
- Changed to use the Windows thread pool instead of the .NET portable thread pool

Fixed:
- Fixed: Some PNG metadata from text chunks is now preserved (Author, Comment, Copyright, and Description)
- Fixed some issues with snapping tool windows when there are multiple monitors with different scaling levels. Sometimes the snapping boundaries would be calculated in the wrong coordinate space and cause snapping to happen at seemingly arbitrary (and weird) locations.
- Fixed an off-by-1 error in the Median Blur effect that was producing incorrect results, especially with radius=1
- Fixed a crash in the Levels adjustment's UI due to some improper value clamping
- Fixed the Red Eye Removal effect so it no longer crashes if the canvas zoom level does not show the whole image
- Fixed the Red Eye Removal effect so that it properly clips to the active selection
- Fixed: View -> Zoom to Selection no longer adjusts the zoom level slightly if used twice in a row
- Fixed: When opening an image with a CMYK color profile, it will be ignored and removed if the image is actually RGB
- Fixed some issues with the mouse cursor briefly being a generic arrow instead of the tool's requested cursor
- Fixed: The installer will no longer silently die on Windows 10 pre-v21H2. It will now correctly show an error message stating that Windows 10 v21H2 is required, and the exit code will be ERROR_OLD_WIN_VERSION
- Fixed: Tooltips now respect dark mode
- Fixed: The Text tool's "Sharp (Modern)" rendering mode has been reverted to use Natural Symmetric rendering instead of Natural Symmetric Downsampled
- Fixed PdnZoomBlurEffect when the AlphaMode property was set to Straight
- Fixed PdnZoomBlurEffect when the BorderMode was set to Soft