Trace types that share the line extraction: one series per path, one value
per sample.
An area fills the band under the line, a bump chart plots ranks instead of
magnitudes, a radar wraps the samples around a circle, and a survival curve
steps down them; all of them are navigated as a multi-line grid, so all of
them are built by buildLineLayer and differ only in the type the
layer announces — which is what makes the trace read the values correctly
(an area reports its stack total, a bump inverts its pitch, a radar pans by
the spoke's angle, a survival curve finds its median).
Trace types that share the line extraction: one series per path, one value per sample.
An area fills the band under the line, a bump chart plots ranks instead of magnitudes, a radar wraps the samples around a circle, and a survival curve steps down them; all of them are navigated as a multi-line grid, so all of them are built by buildLineLayer and differ only in the type the layer announces — which is what makes the trace read the values correctly (an area reports its stack total, a bump inverts its pitch, a radar pans by the spoke's angle, a survival curve finds its median).