blit modulated by tint only, which is 0xffffffff on essentially every keyframe,
so the fade word was decoded, stored and then discarded. Applying it as an ARGB
modulate takes the title composite's edge correlation against the framebuffer
capture of the running game from 0.4597 to 0.9538, both at zero shift. The white
wordmark with its blue outline, the trademark, the copyright and the orange
exploding planet all appear -- the planet because a full-screen blue effect that
rests at alpha 0 had been painting over it at full opacity.
ARGB is measured: across a fade-in the high byte walks 0x00 -> 0x80 -> 0xc0 ->
0xe0 -> 0xff while the low three stay ffffff, and the low 24 bits are 0xffffff on
5276 of the disc's 5453 resting keyframes.
A modulate can only remove pixels, so the risk is a blank screen. Measured: no-op
on 4060 of 5200 sprite elements, partial on 453, hides 687 -- transient HUD
indicators that should not be lit at rest -- and NO build is left with nothing
visible. A disc test asserts that, and that the no-op share stays high, which
also guards the resting rule against drifting onto ramp frames.
Both changes are in one commit because the second is invisible without the first.
Applying fade erased the word PAUSE, which the running-game capture plainly
shows: pgptitle.rat has three runs of two identical keyframes -- pre-roll, hold,
exit -- and the 'later run wins' tie-break grabbed the exit. A group carries the
screen's entry animation AND its exit, so a run ending on the last keyframe is
now excluded unless it is the only one. The title correlation is unchanged.
Element::rest() picked the keyframe with the largest gap to the next keyframe's
time. That reads a keyframe as a value held until the next one; it is the start
of a ramp toward it. A long gap after keyframe k means the screen spends that
time arriving at k+1, so the settled pose is at the far end of the gap.
The title wordmark zooms in over five frames and holds at (184,193) at 100% from
t=251 to t=264. The old rule picked the frame before the long gap: (179,186) at
101%, still mid-zoom.
Measured against the framebuffer capture of the running title screen, which is a
1:1 crop so frame coordinates map directly (confirmed: the copyright line lands
on row 669 in the capture and in both composites). Edge-correlated over the
wordmark box:
plateau (landed) best 0.4597 at shift (0,0)
longest dwell (old) best 0.1511 at shift (+3,+8), 0.1268 at (0,0)
The old composite scores 3x lower and only peaks after being moved, by about the
(-5,-7) that picking kf4 instead of kf5 predicts.
It also fixes six title elements the old rule rested at alpha 0x00 where the
capture plainly shows them, and pteff00.prm - the full-screen fade quad painted
last - which rested at opaque black. That was the blocker on .prm compositing.
Adds tools/re-capture/align_to_capture.py, which is how this was scored, and
turns the .prm test that deliberately asserted the old defect into a guard on
the fix.
Not settled and now the next item: compose ignores the keyframe fade alpha
entirely (blit modulates by tint only), which is why choosing the wrong keyframe
was invisible until now.
