Ebitengine 2.9 Release Notes

v2.9.0

This release mainly adds minor features, bug fixes, and performance improvements.

Starting from Ebitengine 2.9, Go 1.24 or later is required.

Improved Rendering Quality for Vector Graphics

Previously, the vector package used functions such as AppendVerticesAndIndicesForFilling and AppendVerticesAndIndicesForStroke to decompose vector shapes into triangles, which were then rendered. This approach had the following issues:

Edges did not look clean. Ebitengine adopted a method of rendering vector graphics onto a large offscreen buffer and then scaling it down, but both efficiency and quality were unsatisfactory.
It was not possible to render semi-transparent colors.
The Blend option did not behave as expected.

The new approach uses a special shader to create a custom stencil buffer, which is then used to fill with colors. This increases the number of samples per pixel while consuming the same or fewer textures, improving rendering quality. Additionally, instead of drawing multiple overlapping triangles, the finished stencil buffer is filled at once, allowing correct rendering of semi-transparent colors and proper handling of the Blend option. The implementation was inspired by Evan Wallace’s blog post, “Easy Scalable Text Rendering on the GPU”.

The functions added for the new rendering method are mainly vector.FillPath() and vector.StrokePath(). To use the new rendering method, calls to the old AppendVerticesAndIndicesFor… functions need to be replaced with the new ones. The rendering results of the existing AppendVerticesAndIndicesFor… functions remain unchanged. These functions are now deprecated. The deprecated functions will continue to work as long as Ebitengine remains in the same major version, but they may be removed in future major versions.

Comparison between the old and new vector graphics rendering methods

New APIs

Deprecated APIs

Up to 2.8	Since 2.9	Issue
`ebiten.FillRule`		#3153
`ebiten.DrawTrianglesOptions.AntiAlias`	`vector.FillPath()`	#3153
`ebiten.DrawTrianglesOptions.FillRule`	`vector.FillPath()`	#3153
`ebiten.DrawTrianglesShaderOptions.AntiAlias`	`vector.FillPath()`	#3153
`ebiten.DrawTrianglesShaderOptions.FillRule`	`vector.FillPath()`	#3153
`audio.Resample()`	`audio.ResampleReader()`	#3194
`audio.ResampleF32()`	`audio.ResampleReaderF32()`	#3194
`colorm.DrawTrianglesOptions.AntiAlias`		#3153
`colorm.DrawTrianglesOptions.FillRule`		#3153
`text/v2.GoTextFace.Script`	`text/v2.GoTextFace.Language`	#3175
`vector.Path.AppendVerticesAndIndicesForFilling()`	`vector.FillPath()`	#3153
`vector.Path.AppendVerticesAndIndicesForStroke()`	`vector.FillPath()` and `vector.Path.AddStroke()`	#3153
`vector.DrawFilledCircle()`	`vector.FillCircle()`	#3150
`vector.DrawFilledRect()`	`vector.FillRect()`	#3150

Bug Fixes

In addition to the fixes listed below, this release also includes all bug fixes from version 2.8.

Fixed a crash that could occur when moving a window between monitors (#3121).
Fixed incorrect results with ebiten.IsMouseButtonPressed and inpututil.IsMouseButtonJustPressed when using a touchpad (#3137, #3249).
Fixed (*audio.Player).Position() not returning the correct value when the window was in the background (#3154).
Fixed a crash in the Kage shading language when specifying a bool type for a uniform variable (#3165).
Fixed a crash when providing a source that did not properly implement io.Seeker to a decoder (e.g., in the audio/vorbis package) (#3192, #3193).
Fixed ebiten.SetWindowMousePassThrough not working properly when called before startup (#3222).
Fixed occasional screen flickering on macOS (#3278).
Fixed an issue where music could start playing automatically after waking from sleep (#3297).
Other minor fixes

Performance Improvements

Modified so that the result of (*ebiten.Image).SubImage() is cached internally for a certain period of time (#2902).
Other minor performance improvements

v2.9.1

Issues for v2.9.1

Bug Fixes

Fixed an issue where inpututil.IsKeyJustReleased could return true for multiple consecutive ticks (Update calls) even though the key was released only once (#3326).

v2.9.2

Issues for v2.9.2

Bug Fixes

Fixed an issue where vector rendering did not work correctly on images created by SubImage (#3330).

v2.9.3

Issues for v2.9.3

Bug Fixes

Fixed a race condition that occurred during vector rendering on images created by SubImage (#3333).