Spike trap

// Spike trap — 32x32 floor tile, top-down 3/4, key light top-left.// A riveted iron plate set into the floor: a lit frame round a recessed panel pierced by 8 holes (3-2-3, staggered).// The spikes are one rig: each spike is a shaded cone whose visible length h slides out of its hole, so every// state is the same spikes at a different h, occluded back row to front row.// Variants://   idle     loop 8f     — spikes hidden; a faint glint winks from hole to hole//   trigger  one-shot 8f — spikes shoot up past full height, dust puffs out from the plate, spikes settle (== armed f0)//   armed    loop 8f     — spikes up; a glint runs along the tips left to right//   retract  one-shot 6f — spikes sink back into the holes (== idle f0)const CX = 16, GROUND = 29;const PLATE = { x0: 2, x1: 30, y0: 8, y1: 26 };      // top face; the front face is 2px below itconst FULL = 7;                                        // full spike length (px above the hole)const N_LOOP = 8, N_TRIG = 8, N_RET = 6;// holes: [cx, top row y] back row first; 3-2-3 staggeredconst ROWS = [  { y: 11, xs: [8, 16, 24] },  { y: 16, xs: [12, 20] },  { y: 21, xs: [8, 16, 24] },];const HOLES = [];for (const r of ROWS) for (const x of r.xs) HOLES.push({ x, y: r.y });// rank of each hole in a diagonal sweep from the top-left (glint order)const RANK = new Array(HOLES.length);HOLES.map((h, i) => [h.x + 1.4 * h.y, i]).sort((a, b) => a[0] - b[0]).forEach((a, r) => { RANK[a[1]] = r; });// ---- plate --------------------------------------------------------------------------------------function plate(g) {  const { x0, x1, y0, y1 } = PLATE;  g.part("plate", () => {    g.field({ x: [x0, x1], y: [y0, y1 + 2] }, (x, y) => {      if (y > y1) {                                      // front face (thickness): lit at the left end        if (y === y1 + 2) return x < x0 + 3 ? "n1" : "n0";        return x < x0 + 3 ? "n2" : "n1";      }      const dx0 = x - x0, dx1 = x1 - x, dy0 = y - y0, dy1 = y1 - y;      if (dx0 < 2 || dx1 < 2 || dy0 < 2 || dy1 < 2) {        // raised frame: top & left bands face the light, the right and front bands turn away        if (dy0 === 0) return dx1 < 2 ? "n3" : "n4";        if (dx0 === 0) return dy1 < 2 ? "n3" : "n4";        if (dx1 === 0) return "n1";        if (dy1 === 0) return "n1";        if (dx0 === 1 || dy0 === 1) return dx1 < 2 ? "n2" : "n3";        return "n2";      }      // recessed panel: the frame shades its top and left walls, the lower lip catches the light      if (dy0 === 2) return "n0";      if (dx0 === 2) return "n0";      if (dy1 === 2) return "n3";      if (dx1 === 2) return "n2";      // a soft falloff: the panel is a touch brighter toward the top-left      return dx0 + 1.4 * dy0 < 15 ? "n2" : "n1";    });    // rivets on the frame corners and mid-sides    for (const [x, y] of [[x0 + 1, y0 + 1], [x1 - 2, y0 + 1], [x0 + 1, y1 - 1], [x1 - 2, y1 - 1], [CX - 1, y0 + 1], [CX - 1, y1 - 1]]) {      g.pixel(x, y, x < CX && y < y1 - 1 ? "n5" : "n4");      g.pixel(x + 1, y, "n1");    }  });  g.part("stain", () => {    // old blood dried round one hole on the front row    for (const [x, y, k] of [[17, 25, "r0"], [18, 25, "w0"], [14, 25, "w0"], [19, 22, "r0"], [19, 23, "w0"]]) g.pixel(x, y, k);  });}function holes(g, glint) {  g.part("holes", () => {    HOLES.forEach((h, i) => {      const { x, y } = h;      g.pixel(x - 1, y, "ink"); g.pixel(x, y, "ink"); g.pixel(x + 1, y, "n0");      g.pixel(x - 1, y + 1, "n0"); g.pixel(x, y + 1, "ink"); g.pixel(x + 1, y + 1, "n0");      g.line([x - 1, y + 2], [x + 1, y + 2], "n3");        // lower lip catches the light      const k = glint ? glint(i) : 0;                      // a hidden tip catching the light      if (k > 0) g.pixel(x, y + 1, k > 1 ? "n4" : "n3");    });  });}// ---- spikes -------------------------------------------------------------------------------------// cone profile from the tip down: keys for columns cx-1, cx, cx+1 (null = empty); lit on the leftfunction spikeRow(k) {  if (k === 0) return [null, "n5", null];  if (k === 1) return [null, "n4", null];  if (k < 3) return ["n4", "n2", null];  return ["n4", "n3", "n1"];}function spikePixels(cx, hy, h, tip, blood) {  // h = visible length above the hole; hy = the hole's top row (the spike stands in its lower row)  const base = hy + 1, n = Math.round(h), out = [];  for (let r = 0; r < n; r++) {    const y = base - (n - 1) + r, row = spikeRow(r);    const collar = r === n - 1 && n > 2;                   // where it leaves the hole: a darker band    for (let c = 0; c < 3; c++) {      let key = row[c];      if (!key) continue;      if (collar) key = c === 0 ? "n2" : c === 1 ? "n1" : "n0";      if (r <= 1 && tip) key = tip;      if (blood && r >= 2 && r <= 3) key = c === 0 ? "r1" : "r0";      if (blood && r === 4 && c === 1) key = "r0";      out.push([cx + c - 1, y, key]);    }  }  return { base, px: out };}function spikes(g, hs, tipAt) {  // each spike carries its own ink outline, drawn back row to front row, so a front spike is cut out against the  // ones behind it (g.outlined only rings empty pixels; here the spikes stand over the plate)  g.part("spikes", () => HOLES.forEach((hole, i) => {    const h = hs(i);    if (Math.round(h) <= 0) return;    const { base, px } = spikePixels(hole.x, hole.y, h, tipAt ? tipAt(i) : null, i === 6);    const has = new Set(px.map(([x, y]) => x + "," + y));    for (const [x, y] of px) for (const [dx, dy] of [[1, 0], [-1, 0], [0, 1], [0, -1]]) {      const qx = x + dx, qy = y + dy;      if (qy > base || has.has(qx + "," + qy)) continue;      g.pixel(qx, qy, "ink");    }    for (const [x, y, k] of px) g.pixel(x, y, k);  }));}function star(g, x, y, size) {  g.pixel(x, y, "n5");  for (const [dx, dy] of [[1, 0], [-1, 0], [0, 1], [0, -1]]) g.pixel(x + dx, y + dy, size > 1 ? "n5" : "n4");  if (size > 1) for (const [dx, dy] of [[2, 0], [-2, 0], [0, -2]]) g.pixel(x + dx, y + dy, "n4");}// ---- dust ---------------------------------------------------------------------------------------// puffs thrown out from under the plate's edges; stage 1..4: burst, billow, thin out, last motesconst PUFFS = [[3, 21, -1], [28, 19, 1], [7, 28, -1], [24, 28, 1]];const CLOUD = [  null,  ["  54 ", " 4443"],  [" 544  ", "544443", " 3443 "],  [" 4 4  ", "4 4 43", " 3 3  "],  ["  3   ", "3    3", "   3  "],];function dust(g, stage) {  if (stage <= 0 || stage > 4) return;  const rows = CLOUD[stage];  g.detached("dust", () => {    for (const [px, py, s] of PUFFS) {      const w = rows[0].length, x0 = Math.max(0, Math.min(31 - w, px + s * (stage - 1) - (w >> 1)));      const y0 = py - rows.length + 1 - Math.floor((stage - 1) / 2);      rows.forEach((row, j) => {        for (let i = 0; i < row.length; i++) {          const c = row[i];          if (c !== " ") g.pixel(x0 + i, y0 + j, "n" + c);        }      });    }  });}// ---- states -------------------------------------------------------------------------------------// trigger: spikes (h), dust stage per frameconst TRIG = [[0, 0], [9, 1], [6, 2], [8, 3], [7, 4], [7, 0], [7, 0], [7, 0]];const RET = [7, 6, 4, 1, 0, 0];const sweep = (rank) => 1 + Math.floor((rank * 7) / HOLES.length);   // frame (1..7) in which a rank is litfunction holeGlint(f) {  // frame 0 rests (so the one-shots can join it); frames 1..7 the glint crosses the holes diagonally  if (f < 1) return null;  return (i) => (sweep(RANK[i]) === f ? 2 : sweep(RANK[i]) === f - 1 ? 1 : 0);}const SpikeTrap = sprite(pal, (g, t, state) => {  contactShadow(g, CX, GROUND, 15, 2);  g.outlined("ink", () => plate(g));  if (state === "idle") {    const f = Math.round(t * N_LOOP) % N_LOOP;    holes(g, holeGlint(f));    return;  }  holes(g, null);  if (state === "armed") {    const f = Math.round(t * N_LOOP) % N_LOOP;    // frame 0 rests; frames 1..7 the glint walks the tips by rank    const lit = (i) => f >= 1 && sweep(RANK[i]) === f;    spikes(g, () => FULL, (i) => (lit(i) ? "n5" : null));    g.detached("glint", () => {      HOLES.forEach((h, i) => { if (f >= 1 && sweep(RANK[i]) === f && (RANK[i] === 7 || sweep(RANK[i] + 1) !== f)) star(g, h.x, h.y + 1 - (FULL - 1), 1); });    });    return;  }  if (state === "trigger") {    const f = Math.min(N_TRIG - 1, Math.round(t * N_TRIG));    const [h, d] = TRIG[f];    spikes(g, () => h);    dust(g, d);    return;  }  const f = Math.min(N_RET - 1, Math.round(t * N_RET));  spikes(g, () => RET[f]);});submit(SpikeTrap, {  size: [32, 32], origin: "top-left", kind: "icon", scale: 1,  animate: { fps: 10, duration: N_LOOP / 10, loop: true },  anchor: { x: CX, y: GROUND },  variants: [    { name: "idle", args: ["idle"] },    { name: "trigger", args: ["trigger"], animate: { fps: 10, duration: N_TRIG / 10, loop: false } },    { name: "armed", args: ["armed"] },    { name: "retract", args: ["retract"], animate: { fps: 10, duration: N_RET / 10, loop: false } },  ],});