loop: fix the crossfade seam's residual discontinuity, plus six review minors

Normalizes crossfadeWeight over crossfade-1 so the last rendered frame lands at exactly the incoming tap instead of a residual step; corrects the CLAUDE.md invariant and seam test to match. Shares lerpSource/crossfadedSource/maxCrossfade, fixes stale docs/constants, and clears crossfade on the loop-OFF gesture.
2026-07-31 17:59:58 -04:00
parent 0fe4166d7d
commit 3cb22e984d
12 changed files with 172 additions and 83 deletions
@@ -199,9 +199,8 @@ void Voice::start(int note, int velocity, const SampleData& sample, bool declick
                // seam would put the click back one window into the note.
                primeBuf_[static_cast<std::size_t>(i)] =
                    (q < frameCount)
-                        ? crossfadedSource(pcmCh, q,
-                                           instrument::engine::loop::crossfadeWeight(
-                                               loop_, static_cast<double>(q)))
+                        ? crossfadedSource(pcmCh, loop_, q, crossfadeWeight(loop_,
+                                                                            static_cast<double>(q)))
                        : 0.0f;
                ++q;
            }