def act.add

gralha-coverage@0.1.0.1 · cover.bend:288

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

288# A line covers [top, bottom) so a shared vertex counts once; a horizontal line
289# never crosses. Lines whose bottom the scanline has passed are dropped.
290def act.add(l: CovLine, +sy: F32, acc: List<&2, Act>) -> List<&2, Act>:
291  CovLine{x0, y0, x1, y1} = l
292  +ax = x0
293  +ay = y0
294  +bx = x1
295  +by = y1
296  +up = F32.is_lt(ay, by)
297  +bottom = U.max(ay, by)
298  act.keep(F32.is_lt(sy, bottom) && Bool.not(F32.is_eq(ay, by)), ax, ay, ((bx - ax) / (by - ay) : F32), bottom, U.choose(F32, up, 1.0, F32.neg(1.0)), sy, acc)