oxihuman_morph/
neck_wattle_control.rs

1// Copyright (C) 2026 COOLJAPAN OU (Team KitaSan)
2// SPDX-License-Identifier: Apache-2.0
3#![allow(dead_code)]
4
5//! Neck wattle (submental skin laxity) control.
6
7use std::f32::consts::FRAC_PI_6;
8
9#[allow(dead_code)]
10#[derive(Debug, Clone)]
11pub struct NeckWattleConfig {
12    pub max_sag: f32,
13}
14
15impl Default for NeckWattleConfig {
16    fn default() -> Self {
17        Self { max_sag: 1.0 }
18    }
19}
20
21#[allow(dead_code)]
22#[derive(Debug, Clone)]
23pub struct NeckWattleState {
24    pub sag: f32,
25    pub spread: f32,
26    pub config: NeckWattleConfig,
27}
28
29#[allow(dead_code)]
30pub fn default_neck_wattle_config() -> NeckWattleConfig {
31    NeckWattleConfig::default()
32}
33
34#[allow(dead_code)]
35pub fn new_neck_wattle_state(config: NeckWattleConfig) -> NeckWattleState {
36    NeckWattleState {
37        sag: 0.0,
38        spread: 0.0,
39        config,
40    }
41}
42
43#[allow(dead_code)]
44pub fn nwat_set_sag(state: &mut NeckWattleState, v: f32) {
45    state.sag = v.clamp(0.0, state.config.max_sag);
46}
47
48#[allow(dead_code)]
49pub fn nwat_set_spread(state: &mut NeckWattleState, v: f32) {
50    state.spread = v.clamp(0.0, 1.0);
51}
52
53#[allow(dead_code)]
54pub fn nwat_reset(state: &mut NeckWattleState) {
55    state.sag = 0.0;
56    state.spread = 0.0;
57}
58
59#[allow(dead_code)]
60pub fn nwat_is_neutral(state: &NeckWattleState) -> bool {
61    state.sag.abs() < 1e-6 && state.spread.abs() < 1e-6
62}
63
64#[allow(dead_code)]
65pub fn nwat_volume_estimate(state: &NeckWattleState) -> f32 {
66    state.sag * state.spread
67}
68
69#[allow(dead_code)]
70pub fn nwat_sag_angle_rad(state: &NeckWattleState) -> f32 {
71    state.sag * FRAC_PI_6
72}
73
74#[allow(dead_code)]
75pub fn nwat_to_weights(state: &NeckWattleState) -> [f32; 2] {
76    let m = state.config.max_sag;
77    [if m > 1e-9 { state.sag / m } else { 0.0 }, state.spread]
78}
79
80#[allow(dead_code)]
81pub fn nwat_blend(a: &NeckWattleState, b: &NeckWattleState, t: f32) -> [f32; 2] {
82    let t = t.clamp(0.0, 1.0);
83    [
84        a.sag * (1.0 - t) + b.sag * t,
85        a.spread * (1.0 - t) + b.spread * t,
86    ]
87}
88
89#[allow(dead_code)]
90pub fn nwat_to_json(state: &NeckWattleState) -> String {
91    format!(
92        "{{\"sag\":{:.4},\"spread\":{:.4}}}",
93        state.sag, state.spread
94    )
95}
96
97#[cfg(test)]
98mod tests {
99    use super::*;
100    #[test]
101    fn default_neutral() {
102        assert!(nwat_is_neutral(&new_neck_wattle_state(
103            default_neck_wattle_config()
104        )));
105    }
106    #[test]
107    fn set_sag_clamps() {
108        let mut s = new_neck_wattle_state(default_neck_wattle_config());
109        nwat_set_sag(&mut s, 5.0);
110        assert!((0.0..=1.0).contains(&s.sag));
111    }
112    #[test]
113    fn set_spread_clamps() {
114        let mut s = new_neck_wattle_state(default_neck_wattle_config());
115        nwat_set_spread(&mut s, 5.0);
116        assert!((0.0..=1.0).contains(&s.spread));
117    }
118    #[test]
119    fn reset_zeroes() {
120        let mut s = new_neck_wattle_state(default_neck_wattle_config());
121        nwat_set_sag(&mut s, 0.5);
122        nwat_reset(&mut s);
123        assert!(nwat_is_neutral(&s));
124    }
125    #[test]
126    fn volume_product() {
127        let mut s = new_neck_wattle_state(default_neck_wattle_config());
128        nwat_set_sag(&mut s, 0.5);
129        nwat_set_spread(&mut s, 0.4);
130        assert!((nwat_volume_estimate(&s) - 0.2).abs() < 1e-5);
131    }
132    #[test]
133    fn sag_angle_nonneg() {
134        let s = new_neck_wattle_state(default_neck_wattle_config());
135        assert!(nwat_sag_angle_rad(&s) >= 0.0);
136    }
137    #[test]
138    fn to_weights_max() {
139        let mut s = new_neck_wattle_state(default_neck_wattle_config());
140        nwat_set_sag(&mut s, 1.0);
141        assert!((nwat_to_weights(&s)[0] - 1.0).abs() < 1e-5);
142    }
143    #[test]
144    fn blend_at_zero_is_a() {
145        let mut a = new_neck_wattle_state(default_neck_wattle_config());
146        let b = new_neck_wattle_state(default_neck_wattle_config());
147        nwat_set_sag(&mut a, 0.7);
148        let w = nwat_blend(&a, &b, 0.0);
149        assert!((w[0] - 0.7).abs() < 1e-5);
150    }
151    #[test]
152    fn to_json_has_sag() {
153        assert!(
154            nwat_to_json(&new_neck_wattle_state(default_neck_wattle_config())).contains("\"sag\"")
155        );
156    }
157    #[test]
158    fn volume_zero_when_neutral() {
159        let s = new_neck_wattle_state(default_neck_wattle_config());
160        assert!(nwat_volume_estimate(&s).abs() < 1e-6);
161    }
162}
oxihuman_morph/neck_wattle_control.rs

oxihuman_morph/
neck_wattle_control.rs
