[Unreleased]

Use this section for changes made after the 2.2.1 release. Future architectural ideas are tracked separately in ROADMAP.md.

[2.2.1] - 2026-09-09

Optional waitTrailingSpace() for scrolling and mirrored block animations: wait one spacing duration after the final block clears before completing or looping. Disabled by default, captured per queue entry, inherited by reverse entries, and frozen by pause; hard forTime() deadlines still take priority.
AVR regression coverage for trailing-space timing, default and zero-spacing behavior, queue replay, reverse entries, pauses, clock rollover, graceful emission shutdown, and emission resumption.

loopQueue() and noLoopQueue() for whole-sequence repetition. Disabling repetition finishes the current pass; enabling it during a pass retains the full sequence for replay.
AVR simulator regression tests for queue controls, pixel-level replay and pause equivalence, clock rollover, and center/edge bounce output.

Mixed-type min/max comparisons now compile on ESP32 and ESP8266 Arduino cores as well as AVR.
pause() now blocks queue deadline processing and excludes paused time from animation steps, waits, forTime(), and block-emission deadlines.
Repeated pause/resume calls are idempotent. Optional timestamps support the same custom clock used by update().
Center/edge bounces return their tracker to the correct endpoint when changing phase, eliminating out-of-range pixel requests and a wasted clearing interval.

Queued entries occupy their slots until the pass finishes or the queue is cleared, including non-looping passes. queuedAnimations() still reports entries remaining after the active entry in the current pass.
stop() and clearQueue() discard the retained sequence and disable queue repetition. Skipping the final entry wraps when queue looping is enabled.
The queue demo uses automatic replay. API documentation was regenerated.

Universal forTime() modifier for setting a hard maximum duration on direct animations or queued entries. It may be placed immediately before or after enqueue().
enqueueFor() convenience API for time-limited queued animations.
Parameterless enqueueReverseAnim() for a state-preserving logic reversal of the preceding queued animation. Standard loop()/noLoop(), forTime(), and stopBlockEmissionAfter() modifiers configure the reversed entry.
stopBlockEmissionAfter() for direct or queued mirrored and scrolling block animations. New emissions stop at the deadline while active blocks drain naturally before queue advancement.

wait() is always non-looping, preventing an inherited loop setting from indefinitely blocking subsequent queue entries.
animationQueueDemo now documents hard deadlines, state-preserving reversal, graceful block draining, modifier ordering, and automatic queue replay.

Initialize the logical segment count in the generic rows-by-columns matrix constructor. Generic matrix bars now accept pixel updates and animations instead of behaving as zero-segment displays.

Fixed-storage animation queue with enqueue(), startQueue(), clearQueue(), and skipCurrent().
Compile-time SBK_BARDRIVE_QUEUE_CAPACITY setting, defaulting to four.
Queue state inspection through queuedAnimations(), isQueueRunning(), queueOverflowed(), currentQueueIndex(), and isQueueIndexPlaying().
NO_QUEUE_INDEX sentinel for detecting that no queued entry is active.
Non-blocking wait(duration) animation for timed queue pauses without changing pixel states.
blinkPixel() overloads with fixed or independent on/off intervals.
setUpdateInterval() for changing an active animation's primary interval.
animationQueueDemo example for queue construction, live logic inversion, graceful block-emission shutdown, and wait().
Root-level Doxyfile for reproducible API documentation generation.

stop() now terminates looping and queued work and clears mapped pixels; pause() remains the non-destructive way to freeze an animation.
Block and random animations share one construction-time workspace instead of allocating separate buffers.
Animation workspace capacity is derived from the bar segment count and bounded to 64 simultaneous blocks.
Generic live-value pointers share storage where their lifetimes do not overlap.
Fixed-value beatPulse() calculates its interval during setup; the live-BPM overload remains available for pointer-driven BPM changes.
Duration-based bounce interval calculations now use integer arithmetic only.
Documentation and examples now use current driver class names and MatrixPreset terminology.
Doxygen HTML documentation regenerated from the 2.1.0 API and examples.
Minimum driver releases updated to SBK_HT16K33 2.0.1 and SBK_MAX72xx 2.0.5.

Corrected a duplicated lower-bound test in block tracking.
Corrected the uint16_t maximum-value check from an accidental comma expression to 65535.
Corrected block-switch helper names and related comments.
Queue index state is cleared consistently when a queue stops, finishes, or is cleared.

Detailed release notes were not maintained in this format before 2.1.0. Refer to the repository history and release tags for earlier changes.