uzor 1.1.4

Core UI engine — geometry, interaction, input state
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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151

//! Animated value helper for smooth single-value transitions.

use super::math::easing::Easing;

/// Type alias for easing function
pub type EasingFn = fn(f64) -> f64;

fn default_easing_fn(t: f64) -> f64 {
    Easing::EaseOutQuad.ease(t)
}

/// State for animating a single f64 value
#[derive(Clone, Debug)]
pub struct AnimatedValue {
    /// Current interpolated value
    current: f64,
    /// Target value to animate towards
    target: f64,
    /// Value when animation started
    start_value: f64,
    /// Time when animation started
    start_time: f64,
    /// Animation duration in seconds
    duration: f64,
    /// Easing function
    easing: EasingFn,
}

impl AnimatedValue {
    /// Create new animated value
    pub fn new(initial: f64) -> Self {
        Self {
            current: initial,
            target: initial,
            start_value: initial,
            start_time: 0.0,
            duration: 0.3,
            easing: default_easing_fn,
        }
    }

    /// Set the easing function
    pub fn with_easing(mut self, easing: EasingFn) -> Self {
        self.easing = easing;
        self
    }

    /// Set animation duration
    pub fn with_duration(mut self, duration: f64) -> Self {
        self.duration = duration;
        self
    }

    /// Set a new target and start animation
    pub fn animate_to(&mut self, target: f64, time: f64) {
        if (self.target - target).abs() > 0.0001 {
            self.start_value = self.current;
            self.target = target;
            self.start_time = time;
        }
    }

    /// Update animation and return current value
    pub fn update(&mut self, time: f64) -> f64 {
        if self.duration <= 0.0 {
            self.current = self.target;
            return self.current;
        }

        let elapsed = time - self.start_time;
        let t = (elapsed / self.duration).clamp(0.0, 1.0);
        let eased_t = (self.easing)(t);

        self.current = self.start_value + (self.target - self.start_value) * eased_t;
        self.current
    }

    /// Check if animation is in progress
    pub fn is_animating(&self, time: f64) -> bool {
        let elapsed = time - self.start_time;
        elapsed < self.duration && (self.start_value - self.target).abs() > 0.0001
    }

    /// Get current value without updating
    pub fn get(&self) -> f64 {
        self.current
    }

    /// Get target value
    pub fn target(&self) -> f64 {
        self.target
    }

    /// Instantly set value (no animation)
    pub fn set(&mut self, value: f64) {
        self.current = value;
        self.target = value;
        self.start_value = value;
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_animated_value_creation() {
        let value = AnimatedValue::new(5.0);
        assert_eq!(value.get(), 5.0);
        assert_eq!(value.target(), 5.0);
    }

    #[test]
    fn test_animated_value_instant_set() {
        let mut value = AnimatedValue::new(0.0);
        value.set(10.0);
        assert_eq!(value.get(), 10.0);
        assert_eq!(value.target(), 10.0);
        assert!(!value.is_animating(0.0));
    }

    #[test]
    fn test_animated_value_animation() {
        let mut value = AnimatedValue::new(0.0).with_duration(1.0);

        // Start animation to 10.0 at time 0
        value.animate_to(10.0, 0.0);

        // At time 0, should be at start
        assert!((value.update(0.0) - 0.0).abs() < 0.1);

        // At time 0.5 (halfway), should be somewhere between 0 and 10
        let mid = value.update(0.5);
        assert!(mid > 3.0 && mid < 10.0);

        // At time 1.0 (end), should be at target
        assert!((value.update(1.0) - 10.0).abs() < 0.1);

        // Should no longer be animating
        assert!(!value.is_animating(1.5));
    }

    #[test]
    fn test_animated_value_zero_duration() {
        let mut value = AnimatedValue::new(0.0).with_duration(0.0);
        value.animate_to(10.0, 0.0);

        // Should instantly reach target
        assert_eq!(value.update(0.0), 10.0);
    }
}