An EaseCurve is the temporal ease of one segment independent of its
duration and values: the out side of the first key and the in side of
the second, as influence (%) and speed relative to the segment's
average speed (1 = linear, 0 = at rest). Its handles in the normalised
value graph are cubic-bezier points. apply() eases a pair of keys per
dimension, along the motion path for spatial values and as overall
progress for paths and gradients, the way Easy Ease shapes them; an
Auto Bezier key keeps its other side as it plays. measure() reads the
curve a segment plays back. Non-finite numbers are rejected and
influences and speeds clamped.
Test: handles_round_trip_and_reject_non_finite_numbers,
applied_curve_scales_to_each_dimension_and_measures_back,
spatial_curve_follows_the_motion_path,
linear_and_auto_bezier_sides_measure_as_they_play (effectcraft-keyframe).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
cc594a7385