Verbs — bringing it to life

Verbs are the script. Each one names an entity and animates it. They run top-to-bottom, one after another (use par for simultaneous).

Almost every verb takes two optional trailing arguments:

move(sun, (900, 400), 0.8, smooth);
//                     ^dur  ^easing

• [dur] — how long, in seconds (there’s a sensible default).
• [ease] — the motion curve: linear, smooth, in, out, back, bounce, elastic, spring (see Colour & style).

Reveal & hide

draw(sun, 1.2);   // -> trace a stroke on (needs `untraced` first)
erase(sun);       // -> the reverse: un-draw it
show(cap, 0.5);   // -> fade in (needs `hidden` first)
fade(cap);        // -> fade out
type(cap);        // -> typewriter: reveal text character by character

Attention

flash(sun, cyan);  // -> flash to a colour, then restore
pulse(sun);        // -> quick grow-and-settle "look here"
shake(sun);        // -> horizontal shake, an "error/no" gesture
spin(sun, 360);    // -> spin about its centre

Motion

move(p,  (900, 400));   // -> glide to an absolute point
shift(p, (0, -120));    // -> move by a delta (relative)
scale(r, 1.4);          // -> animate uniform scale to 1.4x
rotate(r, 45);          // -> rotate by 45 degrees
grow(arrow, (500, 200));// -> animate a line/arrow endpoint (draws or retargets)

Content & colour

say(cap, "next step");     // -> crossfade a text entity to new words
recolor(sun, lime, 0.5);   // -> permanently animate the colour

The escape hatch — to / set

Named verbs are shortcuts. to animates any single property, for whatever isn’t pre-named:

to(sun, opacity, 0.3, 0.5);   // animate opacity to 0.3 over 0.5s
to(sun, rot, 90);             // rotation to 90 degrees

Properties: pos, color, opacity, scale, rot, trace, hue.

Move the camera

cam((300, 200), 1.0);   // pan the camera centre
zoom(1.6, 0.8);         // zoom to 1.6x

One verb, a whole group

If a name refers to a tag (a group) instead of a single entity, the verb runs on every member at once. This is how you animate a whole graph, table, or loop-generated set in one line:

hidden(g.nodes);     // every node, at t=0
draw(g.edges);       // trace every edge on together
flash(a.cells, cyan);// flash all array cells

More on grouping in the Kits chapter. Next, control when things happen → Timing.