Bars snap to a 2-grain grid and tip into gaps, so piles stack without air (t1)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-24 19:41:04 -04:00
parent 68c021f64b
commit 232f5af6e4
3 changed files with 67 additions and 4 deletions
@@ -0,0 +1,41 @@
+// Resting bars snap into pairs of grains and tip off narrow supports.
+const { load, suite, flatWorld, rect } = require('./harness');
+const { run } = load();
+const { check, done } = suite();
+function fresh() { flatWorld(run, 240, 160, 100); }
+function settle() { run('for (let n = 0; n < 240; n++) entTick();'); }
+fresh();
+rect(run, 39, 60, 39, 99, run('STONE'));
+rect(run, 56, 60, 56, 99, run('STONE'));
+for (const x of [49, 41, 52, 45, 45, 52, 41, 49, 52, 49, 45, 41]) {
+  check('a dropped bar fits above the pit', !!run(`spawnBar(BARCU, ${x}, 64)`)); settle();
+}
+check('twelve bars fill the bottom six grain rows without gaps', run(`(() => {
+  for (let y = 94; y < 100; y++) for (let x = 40; x < 56; x++) if (!occ[y * W + x]) return false;
+  return ents.length === 12;
+})()`), run('JSON.stringify(ents.map(e => [e.ix, e.iy]))'));
+for (const side of [-1, 1]) {
+  fresh();
+  rect(run, side < 0 ? 43 : 40, 80, side < 0 ? 43 : 40, 99, run('STONE'));
+  run('spawnBar(BARCU, 40, 78)'); settle();
+  check('one-cell support tips toward the empty side ' + side, run(`ents[0].iy === 98 && ents[0].ix ${side < 0 ? '<' : '>'} 40`));
+}
+fresh(); rect(run, 40, 80, 41, 99, run('STONE'));
+run('spawnBar(BARCU, 40, 78)'); settle();
+check('half-supported bar stays on its ledge', run('ents[0].ix === 40 && ents[0].iy === 78'));
+fresh(); run('for (const x of [41, 51, 61, 71]) spawnBar(BARCU, x, 70)'); settle();
+check('bars settle on even columns on flat ground', run('ents.every(e => !(e.ix & 1) && e.iy === 98)'));
+for (const obstacle of ['SAND', 'bar']) {
+  fresh(); rect(run, 41, 80, 44, 99, run('STONE'));
+  if (obstacle === 'bar') run('spawnBar(BARFE, 37, 78); spawnBar(BARFE, 45, 78)');
+  else { rect(run, 40, 78, 40, 79, run('SAND')); rect(run, 45, 78, 45, 79, run('SAND')); }
+  run('spawnBar(BARCU, 41, 78); entTick()');
+  check('snap cannot enter ' + obstacle, run('ents.find(e => e.m === BARCU).ix === 41'));
+}
+for (const surface of ['BELTR', 'P_FILTER']) {
+  fresh();
+  run(`for (let x = 40; x < 48; x++) ${surface === 'BELTR' ? 'setCell(80 * W + x, BELTR, 20, 0)' : 'part[80 * W + x] = P_FILTER'}; spawnBar(BARCU, 41, 78)`);
+  run('entTick()');
+  check('settling leaves transport in control on ' + surface, run(surface === 'BELTR' ? 'ents[0].ix === 42' : 'ents[0].ix === 41'));
+}
+done();