def chord.near

gralha-svg-render@0.1.0.1 · svg.bend:169

import Base
import gralha-text-scan@0.1.0.1/scan.bend as U

169# Whether x lies within tol of the chord pq: at most tol from its line and
170# not beyond either end by more than tol.
171def chord.near(+p: Point, +q: Point, +x: Point, +tol: F32) -> Bool:
172  +d = point.sub(q, p)
173  +len = F32.sqrt(point.dot(d, d))
174  +off = point.sub(x, p)
175  U.branch(Bool, F32.is_lt(len, 0.000001), _ => F32.is_le(point.distance(p, x), tol),
176    _ => F32.is_le(F32.abs(chord.cross(d, off)), (tol * len : F32))
177      && F32.is_ge(point.dot(d, off), (F32.neg(tol) * len : F32))
178      && F32.is_le(point.dot(d, off), ((len + tol) * len : F32)))