SirStone
fca899376e
Make danger a function of time-to-arrival instead of flat distance. Bullet
core/aura/corridor heat becomes magnitude(power) * decay(dt), dt = along/speed:
* decay(dt) = exp(-dt/tau) is a function of TIME; a fixed tau projects a
pixel reach of speed*tau, so fast/weak bullets get a longer slope and slow
ones a shorter one — derived from speed = 20 - 3*power, not hand-tuned.
tau = TR_TFIL_HEAT_TAU.
* magnitude(power) scales the near-end heat with power from DAMAGE
(calcBulletDamage = 4p, linear in p; SCORE_PER_BULLET_DAMAGE = 1.0). Hit
probability is FLAT across power (docs/env_reference.md), so risk does not
justify power scaling — the cost of the hit does. Floored at 1.0 so a weak
bullet's near end is never less dangerous than the flat model.
Gain = TR_TFIL_HEAT_POWER_GAIN.
Every source is already f(dt), so the time-indexed planner (evaluate a cell at
the tick the bot would ARRIVE, i.e. heatDecay(dt - arrivalDelay)) is a one-line
change. It is intentionally NOT implemented here.
Default path is byte-identical: with TR_TFIL_HEAT_TIME unset both factors are
exactly 1.0 (IEEE x*1.0 is exact), and the committed golden replay in
common_libs/tests/test_tfil_commit_env.nim (20,026 ticks) still passes
byte-for-byte against the pre-change mover. The debug corridor outline is also
drawn only to the model's reach when enabled, so the GUI shows the shortening.
Offline field measurement (common_libs/tests/measure_tfil_heat_time.nim,
46,054 fixture ticks, tau=9/gain=1): corridor reach drops from 443px
wall-to-wall to 143px mean (32% retained); fraction of tiles > 10 goes
0.61 -> 0.57; largest contiguous safe region 118 -> 140 tiles; mean
distance-to-nearest-safe-tile 49 -> 42px. Saturation stays high because wall
radiance + pillar alone are 44% of tiles over threshold and are untouched.
Registers the three knobs in env_report (report + known-name set).