This PR optimizes accelerates various components of ChroMapper by taking advantage of Span<T>. Iterating over a Span<T> is noticeably faster, even when compared to iterating a List<T> using a for loop. In addition, Span<T> iteration does not allocate memory, unlike a foreach loop.
Made possible by UnityH4xx, a Unity library that uses custom written IL to expose the backing array of a List<T> as a Span<T>. This is official API in .NET 5 and later, but is unfortunately left out of .NET Standard 2.1.
BeatmapObjectCallbackController<T>.RefreshPool is almost entirely rewritten, not only to utilize Span<T> but also using Binary Search to reduce the average runtime from O(n) to O(log n).
Pausing, unpausing, and scrolling through any object-heavy level should see noticeable improvements.
EnumerableExtensions methods now take advantage of Span<T>.
BeatmapObjectCallbackController<T>.GetViewBetween is now Span<T> accelerated, providing a direct view into the MapObjects list rather than allocating an entirely new collection.
CustomEventsGridContainer now uses Span<T> iteration when it previously used for/foreach iteration
RotationCallbackController sees similar accelerations by using both Span<T> and Binary Search
Pausing, unpausing, and scrolling through 360/90 levels dense with rotations should see additional improvements.
MapLoader uses Span<T> to quickly recalculate song bpm time
Strobe Generator has been touched a little bit, being slightly more memory efficient by using the Span<T>-backed GetViewBetween
However, Strobe Generator itself is still largely inefficient thanks to heavy LINQ abuse. It deserves a proper rewrite in due time.
While a little out of PR scope, GridRotationController no longer uses a coroutine to handle 360/90 rotation transitions. This saves some accumulated garbage every frame.
This PR optimizes accelerates various components of ChroMapper by taking advantage of
Span<T>. Iterating over aSpan<T>is noticeably faster, even when compared to iterating aList<T>using aforloop. In addition,Span<T>iteration does not allocate memory, unlike aforeachloop.Made possible by UnityH4xx, a Unity library that uses custom written IL to expose the backing array of a
List<T>as aSpan<T>. This is official API in .NET 5 and later, but is unfortunately left out of .NET Standard 2.1.The Only Thing They Fear is You is a good benchmark map if you want to compare performance improvements in this PR.
ChroMapper code that was touched by this PR:
BeatmapObjectCallbackController<T>.RefreshPoolis almost entirely rewritten, not only to utilizeSpan<T>but also using Binary Search to reduce the average runtime from O(n) to O(log n).EnumerableExtensionsmethods now take advantage ofSpan<T>.BeatmapObjectCallbackController<T>.GetViewBetweenis nowSpan<T>accelerated, providing a direct view into theMapObjectslist rather than allocating an entirely new collection.CustomEventsGridContainernow usesSpan<T>iteration when it previously used for/foreach iterationRotationCallbackControllersees similar accelerations by using bothSpan<T>and Binary SearchMapLoaderusesSpan<T>to quickly recalculate song bpm timeSpan<T>-backedGetViewBetweenGridRotationControllerno longer uses a coroutine to handle 360/90 rotation transitions. This saves some accumulated garbage every frame.