Lottie4J 1.2.8

1.2.8 Fixes the Streaks in Track Mattes

Lottie4J 1.2.8 fixes a regression introduced in 1.2.7: animations with track mattes of different sizes showed horizontal streaks during playback (issue #12), reported by @bruno-obv.

Frames 34 to 67 of the Noto collision emoji: the middle row shows the horizontal streaks Frames 34 to 67 of the Noto collision emoji: the middle row shows the horizontal streaks

The cause was the snapshot reuse added to the MatteRenderer for performance. Taking a snapshot into an image that is smaller than the matte got the result cropped and then stretched. The renderer now only reuses its cached snapshot image when the size matches the matte, so the performance gains of 1.2.7 stay in place without the visual glitches.

Two changes to the tests:

  • A new regression test compares sequential playback with a fresh seek on every frame, so differences between those two paths are caught. The Noto “collision” emoji was added to the comparison tests.
  • PR #14: the rendering comparison tests now disable adaptive off-screen scaling, so they measure rendering fidelity only. Before, the scores of heavy animations depended on how busy the CI runner was, which made the build flaky. There are no library code changes in this one.

Thanks to @bruno-obv for the detailed bug report and fix!

See the full changelog for the details, or the GitHub diff between 1.2.7 and 1.2.8.