Sim.vv_half_head: def of bend-prot@0.1.0.0
Import: import bend-prot@0.1.0.0/sim.bend as Sim
Lines 175-181 of bend-prot@0.1.0.0/sim.bend: https://jend.leeeet.dev/read.txt?path=bend-prot@0.1.0.0/sim.bend&start_line=175&end_line=181

import Base
import bend-prot@0.1.0.0/geom.bend as G

# Velocity Verlet halves over explicit state (forces must be fresh).
def vv_half_head(h: DynAtom, +dt: F32) -> DynAtom:
  match h:
    case DA{serial, elem, pos, vel, +frc, +mass}:
      acc = G.Vec3.scale(((1.0 / mass : F32) * acc_conv() : F32), frc)
      +vh = G.Vec3.add(vel, G.Vec3.scale((0.5 * dt : F32), acc))
      DA{serial, elem, G.Vec3.add(pos, G.Vec3.scale(dt, vh)), vh, frc, mass}

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.div
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.mul
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/geom.bend&name=Vec3.add
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/geom.bend&name=Vec3.scale
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/sim.bend&name=DynAtom
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/sim.bend&name=acc_conv