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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180

//! Data set interpolation for `mint` `Vector3` and `Quaternion`.
//!
//! Can be extended by users to provide their own data types to interpolate over, using the
//! `InterpolationPrimitive` trait.
//!
//! ## Examples
//!
//! ```
//! use minterpolate::catmull_rom_spline_interpolate;
//!
//! let input = vec![0., 1., 2., 3., 4.];
//! let output = vec![
//!     [1., 0., 0.],
//!     [0., 0., 0.],
//!     [1., 0., 0.],
//!     [0., 0., 0.],
//!     [-1., 0., 0.],
//!     [0., 0., 0.],
//!     [-1., 0., 0.],
//! ];
//! catmull_rom_spline_interpolate(0.5, &input, &output, false);
//! ```

extern crate mint;
extern crate num;

#[cfg(feature = "serde")]
#[macro_use]
extern crate serde;

pub use catmull_rom_spline::catmull_rom_spline_interpolate;
pub use cubic_spline::cubic_spline_interpolate;
pub use linear::linear_interpolate;
pub use primitive::InterpolationPrimitive;
pub use quasi_spherical_linear::quasi_spherical_linear_interpolate;
pub use spherical_linear::spherical_linear_interpolate;
pub use step::step_interpolate;

mod primitive;
mod linear;
mod spherical_linear;
mod step;
mod cubic_spline;
mod catmull_rom_spline;
mod quasi_spherical_linear;

use std::fmt;

/// Calculate the keyframe index in the input collection
///
/// ### Parameters
///
/// - `input`: the input value to the function
/// - `inputs`: list of discrete input values for each keyframe
///
/// ### Returns
///
/// The index into the `inputs`, corresponding to the given `input`.
///
pub fn get_input_index(input: f32, inputs: &[f32]) -> Option<usize> {
    if input < inputs[0] {
        None
    } else {
        Some(
            inputs
                .binary_search_by(|v| v.partial_cmp(&input).unwrap())
                .unwrap_or_else(|index| index - 1),
        )
    }
}

/// Calculate the keyframe index in the input collection, and the interpolation factor between the
/// current keyframe and the next keyframe.
///
/// ### Parameters
///
/// - `input`: the input value to the function
/// - `inputs`: list of discrete input values for each keyframe
///
/// ### Returns
///
/// The index into the `inputs`, corresponding to the given `input`, and also the interpolation
/// factor, i.e. the distance traveled between the current keyframe and the next keyframe.
///
pub fn get_interpolation_factor(input: f32, inputs: &[f32]) -> Option<(usize, f32)> {
    get_input_index(input, inputs).map(|index| {
        if index >= inputs.len() - 1 {
            (index, 0.)
        } else {
            (
                index,
                (input - inputs[index]) / (inputs[index + 1] - inputs[index]),
            )
        }
    })
}

/// Supported interpolation functions
#[derive(Clone)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub enum InterpolationFunction<T>
where
    T: InterpolationPrimitive,
{
    /// Linear interpolation
    Linear,
    /// Spherical linear interpolation
    SphericalLinear,
    /// Quasi spherical linear interpolation
    QuasiSphericalLinear,
    /// Step interpolation
    Step,
    /// Catmull-Rom spline interpolation
    CatmullRomSpline,
    /// Cubic Hermite spline interpolation
    CubicSpline,
    /// Generic function
    #[cfg_attr(feature = "serde", serde(skip_serializing, skip_deserializing))]
    Function(fn(f32, &[f32], &[T], bool) -> T),
}

impl<T> InterpolationFunction<T>
where
    T: InterpolationPrimitive + Copy,
{
    pub fn interpolate(&self, input: f32, inputs: &[f32], outputs: &[T], normalize: bool) -> T {
        match *self {
            InterpolationFunction::Linear => linear_interpolate(input, inputs, outputs, normalize),
            InterpolationFunction::SphericalLinear => {
                spherical_linear_interpolate(input, inputs, outputs, normalize)
            }
            InterpolationFunction::QuasiSphericalLinear => {
                quasi_spherical_linear_interpolate(input, inputs, outputs, normalize)
            }
            InterpolationFunction::Step => step_interpolate(input, inputs, outputs, normalize),
            InterpolationFunction::CubicSpline => {
                cubic_spline_interpolate(input, inputs, outputs, normalize)
            }
            InterpolationFunction::CatmullRomSpline => {
                catmull_rom_spline_interpolate(input, inputs, outputs, normalize)
            }
            InterpolationFunction::Function(ref f) => f(input, inputs, outputs, normalize),
        }
    }
}

impl<T> fmt::Debug for InterpolationFunction<T>
where
    T: InterpolationPrimitive,
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            InterpolationFunction::Linear => write!(f, "Linear"),
            InterpolationFunction::SphericalLinear => write!(f, "SphericalLinear"),
            InterpolationFunction::QuasiSphericalLinear => write!(f, "QuasiSphericalLinear"),
            InterpolationFunction::Step => write!(f, "Step"),
            InterpolationFunction::CatmullRomSpline => write!(f, "CatmullRomSpline"),
            InterpolationFunction::CubicSpline => write!(f, "CubicSpline"),
            InterpolationFunction::Function(_) => write!(f, "Function"),
        }
    }
}

impl<T> PartialEq for InterpolationFunction<T>
where
    T: InterpolationPrimitive,
{
    fn eq(&self, other: &InterpolationFunction<T>) -> bool {
        use self::InterpolationFunction::*;
        match (self, other) {
            (&Linear, &Linear) => true,
            (&SphericalLinear, &SphericalLinear) => true,
            (&QuasiSphericalLinear, &QuasiSphericalLinear) => true,
            (&Step, &Step) => true,
            (&CatmullRomSpline, &CatmullRomSpline) => true,
            (&CubicSpline, &CubicSpline) => true,
            _ => false, // Functions should never be equal
        }
    }
}