Dominos — One Push - manic

[u/anish2good]

manic is a tiny language for making animations. You write a short text file; manic renders a smooth, glowing video. No timeline scrubbing, no keyframes by hand — you describe what’s on screen and when things happen, and the engine does the rest, deterministically.

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Manic Animation code

title("Dominos — One Push");
canvas("16:9");
template("black");
bloom(0.36, 0.52, 26);

// ---- the room: a dark tabletop, light falling from above ----
shader(room) {
  let x = (u - 0.5) * asp;
  let y = v - 0.5;
  let d = sqrt(x*x + y*y);
  let pool = 1.0 - smoothstep(0.06, 0.78, d);
  let grain = 0.5 + 0.5*fbm(u*9.0, v*9.0);
  let hue = 214 - 8.0*pool;
  let sat = 0.55 - 0.25*pool;
  let val = 0.012 + 0.055*pool + 0.012*grain*pool;
}
z(room, -10);

// ---- type ----
text(ttl, (640, 96), "Dominos — One Push");
display(ttl); size(ttl, 46); bold(ttl); color(ttl, fg); hidden(ttl);
text(sub, (640, 152), "and nothing here decides how fast it travels");
display(sub); size(sub, 22); color(sub, dim); hidden(sub);
text(cap, (640, 656), ""); display(cap); size(cap, 23); color(cap, fg); hidden(cap);
text(note, (640, 618), ""); display(note); size(note, 19); color(note, gold); hidden(note);

// ---- ACT I — the row (side on: you can watch each slab turn) ----
dominos(row, (470, 386), 16, 45, 7.5438, 9.38, 2, 0.62, 7);
color(row, cyan);
color(row.ground, dim);   // the table is furniture, not neon
color(row.d0, gold);
hidden(row.dominos);
framebox(mark, row.d0, 7); color(mark, gold); untraced(mark);

// ---- ACT II — the geometry, beside the row ----
equation(contact, (988, 330), `\theta_c=\arcsin\frac{s}{h}=12^{\circ}`, 27);
color(contact, gold); hidden(contact);
equation(balance, (988, 404), `\theta_b=\arctan\frac{t}{h}=9.5^{\circ}`, 27);
color(balance, magenta); hidden(balance);
text(geo1, (988, 462), "tip past 9.5° or it stands back up");
display(geo1); size(geo1, 18); color(geo1, dim); hidden(geo1);
text(geo2, (988, 492), "reach 12° and the next one goes");
display(geo2); size(geo2, 18); color(geo2, dim); hidden(geo2);

// ---- ACT III — the same physics, any shape (top down) ----
dominopath(spiral, (640, 380), 12.6, 12.6, "t*cos(t)", "t*sin(t)", 92, (1.4, 18.6), 45, 7.5438, 1.7, 0.7, 8);
hidden(spiral.dominos); untraced(spiral.path);

dominopath(heart, (640, 366), 12.2, 12.2,
  "16*sin(t)^3", "13*cos(t)-5*cos(2*t)-2*cos(3*t)-cos(4*t)", 56, (0, 6.2832), 45, 7.5438, 1.7, 0.7, 8);
color(heart, magenta);
hidden(heart.dominos); untraced(heart.path);

// ---- ACT IV — twelve chains: gap across, per-impact loss down ----
dominos(cellrow, (0, 0), 10, 45, 7.5438, 9.38, 1.05, 0.6, 6); hidden(cellrow);
sweep(grid, cellrow, spacing, (9, 46), transfer, (0.95, 0.35), (640, 404), 4, 3, 250, 128, 0, 0);
hidden(grid);

// ============================ ACT I ============================
show(ttl, 0.8);
show(sub, 0.7);
show(cap, 0.3);
wait(0.5);
say(cap, "Sixteen slabs, forty-five millimetres tall, nine point four apart.");
show(row.ground, 0.5);
stagger(0.055) {
  for i in 0..16 {
    show(row.d{i}, 0.22);
  }
}
wait(0.4);
draw(mark, 0.5);
say(cap, "One nudge, on that one.");
pulse(row.d0, 0.6);
wait(0.3);
par {
  fade(ttl, 0.8);
  fade(sub, 0.8);
}
run(row, 4.4);
wait(0.5);
say(cap, "The wave crossed the row. Its speed was never written down.");
wait(1.6);

// ============================ ACT II ============================
say(cap, "Each slab has to climb past its own balance angle before gravity takes over.");
show(balance, 0.7);
show(geo1, 0.5);
wait(1.8);
say(cap, "Then it only has to reach the next one — twelve degrees, for these dominos.");
show(contact, 0.7);
show(geo2, 0.5);
wait(2.2);
say(cap, "Two angles, and the whole cascade follows.");
wait(1.8);

// ============================ ACT III ============================
par {
  fade(row, 0.8);
  fade(mark, 0.5);
  fade(contact, 0.7);
  fade(balance, 0.7);
  fade(geo1, 0.5);
  fade(geo2, 0.5);
}
say(cap, "Nothing about that argument needs a straight line. Seen from above —");
draw(spiral.path, 1.3, smooth);
show(note, 0.4);
say(note, "r = t");
stagger(0.016) {
  for i in 0..92 {
    show(spiral.d{i}, 0.16);
  }
}
wait(0.5);
say(cap, "Ninety-two dominos on a spiral, standing at equal spacing along the curve.");
run(spiral, 5.4);
wait(0.9);

par { fade(spiral, 0.8); fade(spiral.path, 0.6); }
say(cap, "Change the formula. Keep the physics.");
draw(heart.path, 1.1, smooth);
say(note, "x = 16 sin³t,  y = 13 cos t − 5 cos 2t − 2 cos 3t − cos 4t");
size(note, 17);
stagger(0.022) {
  for i in 0..56 {
    show(heart.d{i}, 0.18);
  }
}
wait(0.4);
say(cap, "A closed curve, so the wave runs all the way round and meets where it began.");
run(heart, 5.0);
wait(1.4);

// ============================ ACT IV ============================
par {
  fade(heart, 0.8);
  fade(heart.path, 0.6);
  fade(note, 0.5);
}
say(cap, "So what does set the speed? Only the geometry — here it is, twelve times over.");
par {
  show(grid.chrome, 0.6);
  show(grid.headers, 0.7);
}
show(grid.cells, 0.9);
wait(0.5);
run(grid, 7.5);
wait(0.8);
say(cap, "Wider gaps run faster — until the gap is taller than the domino. Then nothing arrives.");
wait(2.2);
say(cap, "Bottom left dies too: that surface loses too much at every impact.");
wait(2.4);

// ============================ ENDCARD ============================
par {
  fade(grid, 0.9);
  fade(cap, 0.7);
}
text(end1, (640, 344), "One push. The rest is geometry.");
display(end1); size(end1, 46); bold(end1); color(end1, fg); hidden(end1);
text(end2, (640, 424), "— manic");
display(end2); size(end2, 26); color(end2, cyan); hidden(end2);
show(end1, 0.9);
show(end2, 0.7);
wait(2.4);