Visgraph.first_half: def of bend-visgraph@2.0.0.0
Import: import bend-visgraph@2.0.0.0/visgraph.bend as Visgraph
Lines 760-771 of bend-visgraph@2.0.0.0/visgraph.bend: https://jend.leeeet.dev/read.txt?path=bend-visgraph@2.0.0.0/visgraph.bend&start_line=760&end_line=771

import Base

# How many of the first `count` of `len` points do half the sweeps' work. A
# natural sweep walks every point right of its start, so the first c starts
# walk c (2 len - 1 - c) / 2 points; a horizontal sweep stops early, so
# halving the starts is close enough.
def first_half(g: Visibility, +len: U32, +count: U32) -> U32:
  match g:
    case Natural{}:
      +b = F32.sub(F32.mul(2.0, U32.to_f32(len)), 1.0)
      +c = U32.to_f32(count)
      U32.min(count, F32.to_u32(F32.div(F32.sub(b, F32.sqrt(F32.sub(F32.mul(b, b), F32.mul(2.0, F32.mul(c, F32.sub(b, c)))))), 2.0)))
    case Horizontal{}:
      U32.div(count, 2)

Uses (10):
  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=Base/base.bend&name=F32.sqrt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.to_u32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.div
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.min
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.to_f32
  https://jend.leeeet.dev/definition.txt?path=bend-visgraph@2.0.0.0/visgraph.bend&name=Visibility