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
|
/**
* An individual leaf silhouette. `pathData` is the `d` attribute of an
* `<path>` inside a `<symbol>` with the given viewBox. Rendered at various
* pixel sizes; the aspect ratio derives from viewBox.
*/
export interface LeafVariant {
readonly id: string
readonly viewBox: string
readonly pathData: string
}
/**
* One leaf in flight. `x` / `y` are in CSS pixels from the top-left of the
* scene container. `rotation` is degrees. `swayPhase` offsets the horizontal
* sway oscillation per leaf so the cloud doesn't drift in sync.
*/
export interface Leaf {
readonly id: number
readonly variantId: string
readonly color: string
readonly size: number
readonly x: number
readonly y: number
readonly vx: number
readonly vy: number
readonly rotation: number
readonly rotationSpeed: number
readonly swayPhase: number
readonly swayFrequency: number
readonly settled: boolean
}
/** Viewport dimensions and the y-coordinate where leaves settle. */
export interface SceneDimensions {
readonly width: number
readonly height: number
readonly groundY: number
}
/**
* The three gust flavours the wind system can emit. Each has its own
* duration, strength, and particle-spawning profile.
*
* breeze small, slow, gentle, frequent — common idle motion
* gust medium, strong, mostly straight — occasional sweep
* whirl small, circular — rare twirl that spirals around its centre
*/
export type GustKind = 'breeze' | 'gust' | 'whirl'
/**
* A wisp of visible air inside a gust — a short-lived dot that traces the
* gust's flow. Rendered as a small semi-transparent circle with opacity
* computed from `ageMs / lifetimeMs`.
*/
export interface WindParticle {
readonly id: number
readonly x: number
readonly y: number
readonly vx: number
readonly vy: number
readonly ageMs: number
readonly lifetimeMs: number
readonly size: number
}
/**
* A localised wind event. Lives for `totalDurationMs`, during which it
* applies force to leaves within `radius` of (`centerX`, `centerY`) and
* spawns `particles` that trace the wind's motion.
*/
export interface Gust {
readonly id: number
readonly kind: GustKind
readonly centerX: number
readonly centerY: number
readonly radius: number
readonly strength: number
readonly direction: number
readonly elapsedMs: number
readonly totalDurationMs: number
readonly particles: readonly WindParticle[]
readonly nextParticleSpawnInMs: number
}
/**
* The overall wind state. A constant horizontal prevailing wind drifts
* every leaf leftward at a low speed. Gusts are seldom, one at a time,
* and superimposed on the prevailing flow — they only apply within their
* own radius.
*/
export interface WindSystem {
readonly prevailingVx: number
readonly prevailingVy: number
readonly activeGust: Gust | null
readonly nextGustInMs: number
}
|
