All files / web/src/components/toys/number-line/constants/demos tauDemoNarration.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/**
 * Tau Demo Narration Segments
 *
 * Matches the tauDemo.ts animation: a circle with radius 1 (diameter 2)
 * is constructed on the number line, then rolls one full turn.
 * The distance it rolls is tau (2*pi ~ 6.283).
 *
 * Progress ranges from tauDemo.ts:
 *   CONSTRUCTION (0.00–0.30):
 *     Highlight  0.00–0.06  "1 to edge" glows on axis
 *     Pivot      0.06–0.15  segment swings to vertical
 *     Sweep      0.15–0.255 arc traces full circle (with compass arm)
 *     Treads     0.255–0.30 tire marks sprout
 *   ROLLING (0.30–0.92):
 *     Circle rolls rightward; pi halfway mark appears at t >= 0.5
 *   LABELS (0.92–1.00):
 *     "tau", "full turn", "C = tau*r" fade in
 */

import type { DemoNarrationSegment } from './useConstantDemoNarration'

/** Shared voice direction for the tau demo narrator. */
export const TAU_DEMO_TONE =
  'You are an excited, warm science teacher for a really smart 5-year-old. ' +
  'Use everyday objects like bicycle wheels, hula hoops, and merry-go-rounds. Be full of wonder.'

export const TAU_DEMO_SEGMENTS: DemoNarrationSegment[] = [
  // ── Construction ──────────────────────────────────────────────
  {
    // Seg 0: Highlight — the red "1 to edge" stick appears
    ttsText:
      'See that red stick? It goes from the very center of a wheel all the way to the edge. ' +
      "That's called the radius — one unit from center to edge.",
    startProgress: 0.0,
    endProgress: 0.06,
    animationDurationMs: 5000,
    scrubberLabel: 'The radius',
  },
  {
    // Seg 1: Pivot — stick swings up to vertical
    ttsText: "Let's stand it up — whoosh! " + "Now let's build a circle around it.",
    startProgress: 0.06,
    endProgress: 0.15,
    animationDurationMs: 3500,
    scrubberLabel: 'Stand it up',
  },
  {
    // Seg 2: Sweep — teal arc traces with compass arm
    ttsText:
      'See the compass spinning around? ' +
      "It's drawing a big circle — like tracing around a hula hoop! " +
      'The radius is the whole stick, so this is going to be a nice big wheel.',
    startProgress: 0.15,
    endProgress: 0.255,
    animationDurationMs: 5000,
    scrubberLabel: 'Draw the circle',
  },
  {
    // Seg 3: Treads appear — transition naturally from circle to wheel
    ttsText:
      "Now let's turn it into a real wheel! " +
      'See those little bumps popping up? Those are the tire treads.',
    startProgress: 0.255,
    endProgress: 0.3,
    animationDurationMs: 3000,
    scrubberLabel: 'Tire treads',
  },

  // ── Rolling ───────────────────────────────────────────────────
  {
    // Seg 4: First stretch of rolling, before pi mark
    ttsText:
      'And off it goes! Our big wheel is rolling along the number line. ' +
      "Let's see how far one full turn takes it!",
    startProgress: 0.3,
    endProgress: 0.55,
    animationDurationMs: 5500,
    scrubberLabel: 'Rolling!',
  },
  {
    // Seg 5: Passing the pi halfway mark
    ttsText:
      "Look! We just passed pi — but we're only halfway around! " +
      'The wheel has so much more spinning to do.',
    startProgress: 0.55,
    endProgress: 0.72,
    animationDurationMs: 5000,
    scrubberLabel: 'Passing pi',
  },
  {
    // Seg 6: Final stretch of rolling
    ttsText:
      'Keep going, keep going... almost one full turn... ' + 'past four, past five, past six...',
    startProgress: 0.72,
    endProgress: 0.92,
    animationDurationMs: 5000,
    scrubberLabel: 'Keep going',
  },

  // ── Labels ────────────────────────────────────────────────────
  {
    // Seg 7: Final reveal
    ttsText:
      'There it is! That number is called tau. ' +
      "It's about six point two eight — exactly twice pi! " +
      'Tau is the distance a wheel rolls in one full turn, ' +
      'measured from its center to its edge. ' +
      'One full spin, one tau — easy to remember!',
    startProgress: 0.92,
    endProgress: 1.0,
    animationDurationMs: 8000,
    scrubberLabel: "It's tau!",
  },
]