The renderer’s word that it holds a live retained buffer for this
(command, slot) identity, stamped with the retained-feed generation the
buffer was captured under. Only confirmed spans may skip materialization:
an unconfirmed span’s primitives are the renderer’s only way to draw it
in the same frame. The stamp is what keeps the word LIVE: a confirmation
from a dead slot universe (renderer replaced, device lost, root-scale
change) stops matching the epoch declared for the build and bypass fails
closed instead of trusting a buffer that no longer exists.
Whether the renderer has confirmed a live retained buffer for this
identity UNDER THE EPOCH DECLARED FOR THIS BUILD (readable by tests
driving the recorder by hand). No declared epoch means no consumer for
bypassed spans, so nothing may skip materialization; a stored generation
from another epoch is a buffer of a dead slot universe.
Declares that the renderer consuming graphs built on this thread retains
draw-run spans by identity, so scene building should verify command
recordings and attach cranpose_ui_graphics::CommandReplayFrames to
the runs it builds. The epoch names the renderer’s retained-slot
universe: bumping it (device loss, scale change — anything that dropped
slots wholesale) resets every command’s verification state, so no frame
ever references a slot from a dead universe. Renderers that draw every
primitive (pixels) never call this and never pay for verification.
Lends the renderer’s frame worker pool to command verification: while
set, segment commits at a record boundary run across the pool’s lanes
instead of on the build thread alone. None (the default, and the wasm
state) keeps verification serial.