// ============================================================
//  STIPPLE — CLOSED-LOOP GENERATION WITH coverat
//  The history queries let the program read what's already been sewn
//  and branch on it — open-loop becomes closed-loop. Here we scatter
//  little dots but only where the fabric ISN'T full yet: coverat(p)
//  reports thread coverage in LAYERS (the same unit as the heatmap and
//  maxdensity), live and in sewing order, so the fill self-levels toward
//  an even target instead of clumping. The queries draw nothing and use
//  no randomness, so "same seed → same design" still holds exactly.
//
//  The discipline that keeps a feedback loop safe: a HARD iteration cap
//  (repeat tries [ … ]) rather than `while not full`, so the loop always
//  terminates even if the target is unreachable.
// ============================================================

seed 7

let radius = 40     // [20:1:46] disc to fill, mm
let target = 1.8    // [0.6:0.1:3.0] stop crowding a spot past this many layers
let dot    = 0.7    // [0.4:0.1:1.5] dot radius, mm
let gap    = 2.2    // [1:0.1:4]   keep new dots this far from the nearest one
let tries  = 4000   // [500:500:8000] hard cap on attempts (bounded loop)

color 1
stitchlen 1.2

repeat tries [
  // a candidate point, uniform-ish over the disc's bounding box
  let p = [random(2 * radius) - radius, random(2 * radius) - radius]

  // three pure, zero-draw guards, read against everything sewn so far:
  //   • inside the disc
  //   • the fabric here is not yet at the target coverage
  //   • not on top of an existing dot (sewnwithin stays O(local))
  if vlen(p) < radius and coverat(p) < target and len(sewnwithin(p, gap)) = 0 [
    up
    setpos(p)
    down
    arc 360 dot          // a small closed ring = one stippled dot
    trim
  ]
]

// A second colour threads a few connectors between near neighbours,
// using nearestsewn — proximity logic that never scans the whole history.
color 4
let probe = [0, 0]
if len(stitchedpoints()) > 0 [
  let here = nearestsewn(probe)
  up setpos(here) down
]