argui-animation 0.1.0

Animation timing and interpolation for Argui interfaces
Documentation 
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
152
153
154
155
156
157
158
159
160

use crate::Duration;
use std::fmt;

#[derive(Clone, Copy, Debug, PartialEq)]
pub enum Iterations {
    Finite(f64),
    Infinite,
}

impl Default for Iterations {
    fn default() -> Self {
        Self::Finite(1.0)
    }
}

#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
pub enum Direction {
    #[default]
    Normal,
    Reverse,
    Alternate,
    AlternateReverse,
}

#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
pub enum FillMode {
    #[default]
    None,
    Forwards,
    Backwards,
    Both,
}

impl FillMode {
    pub(crate) const fn fills_before(self) -> bool {
        matches!(self, Self::Backwards | Self::Both)
    }

    pub(crate) const fn fills_after(self) -> bool {
        matches!(self, Self::Forwards | Self::Both)
    }
}

#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Timing {
    pub duration: Duration,
    pub delay: Duration,
    pub end_delay: Duration,
    pub iterations: Iterations,
    pub direction: Direction,
    pub fill: FillMode,
    pub playback_rate: f64,
}

impl Timing {
    #[must_use]
    pub const fn new(duration: Duration) -> Self {
        Self {
            duration,
            delay: Duration::ZERO,
            end_delay: Duration::ZERO,
            iterations: Iterations::Finite(1.0),
            direction: Direction::Normal,
            fill: FillMode::None,
            playback_rate: 1.0,
        }
    }

    #[must_use]
    pub const fn delay(mut self, delay: Duration) -> Self {
        self.delay = delay;
        self
    }

    #[must_use]
    pub const fn end_delay(mut self, end_delay: Duration) -> Self {
        self.end_delay = end_delay;
        self
    }

    #[must_use]
    pub const fn iterations(mut self, iterations: Iterations) -> Self {
        self.iterations = iterations;
        self
    }

    #[must_use]
    pub const fn direction(mut self, direction: Direction) -> Self {
        self.direction = direction;
        self
    }

    #[must_use]
    pub const fn fill(mut self, fill: FillMode) -> Self {
        self.fill = fill;
        self
    }

    #[must_use]
    pub const fn playback_rate(mut self, playback_rate: f64) -> Self {
        self.playback_rate = playback_rate;
        self
    }

    pub(crate) fn validate(self) -> Result<Self, TimingError> {
        let iterations_valid = match self.iterations {
            Iterations::Finite(value) => value.is_finite() && value > 0.0,
            Iterations::Infinite => true,
        };
        if self.duration == Duration::ZERO {
            Err(TimingError::ZeroDuration)
        } else if !iterations_valid {
            Err(TimingError::InvalidIterations)
        } else if !self.playback_rate.is_finite() || self.playback_rate == 0.0 {
            Err(TimingError::InvalidPlaybackRate)
        } else {
            Ok(self)
        }
    }

    pub(crate) fn active_seconds(self) -> f64 {
        match self.iterations {
            Iterations::Finite(iterations) => self.duration.as_secs_f64() * iterations,
            Iterations::Infinite => f64::INFINITY,
        }
    }

    pub(crate) fn total_seconds(self) -> f64 {
        self.delay.as_secs_f64() + self.active_seconds() + self.end_delay.as_secs_f64()
    }
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum TimingError {
    ZeroDuration,
    InvalidIterations,
    InvalidPlaybackRate,
    InvalidKeyframes,
}

impl fmt::Display for TimingError {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::ZeroDuration => {
                formatter.write_str("animation duration must be greater than zero")
            }
            Self::InvalidIterations => {
                formatter.write_str("animation iterations must be positive and finite, or infinite")
            }
            Self::InvalidPlaybackRate => {
                formatter.write_str("animation playback rate must be finite and non-zero")
            }
            Self::InvalidKeyframes => {
                formatter.write_str("keyframes must be finite, sorted, and cover offsets 0..=1")
            }
        }
    }
}

impl std::error::Error for TimingError {}