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comparison interpreters/src/th06/interpolator.rs @ 757:21b186be2590

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Split the Rust version into multiple crates.
author Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
date Tue, 05 Jan 2021 02:16:32 +0100
parents src/th06/interpolator.rs@5016c09e5d7c
children
comparison
equal deleted inserted replaced
756:4d91790cf8ab 757:21b186be2590
1 //! Animation runner.
2
3 #[derive(Debug, Clone, Copy, PartialEq)]
4 pub(crate) enum Formula {
5 Linear,
6 Power2,
7 InvertPower2,
8 }
9
10 impl Formula {
11 fn apply(&self, x: f32) -> f32 {
12 match self {
13 Formula::Linear => x,
14 Formula::Power2 => x * x,
15 Formula::InvertPower2 => 2. * x - x * x,
16 }
17 }
18 }
19
20 macro_rules! generate_interpolator {
21 ($name:ident, $n:tt) => {
22 #[derive(Debug, Clone)]
23 pub(crate) struct $name<T> {
24 start_values: [T; $n],
25 end_values: [T; $n],
26 start_frame: u32,
27 end_frame: u32,
28 formula: Formula,
29 }
30
31 impl<T> $name<T>
32 where f32: From<T>,
33 T: From<f32>,
34 T: std::ops::Sub<Output = T>,
35 T: std::ops::Add<Output = T>,
36 T: Copy,
37 T: Default,
38 {
39 pub fn new(start_values: [T; $n], start_frame: u32, end_values: [T; $n], end_frame: u32, formula: Formula) -> $name<T> {
40 $name {
41 start_values,
42 end_values,
43 start_frame,
44 end_frame,
45 formula,
46 }
47 }
48
49 pub fn set_start(&mut self, frame: u32, values: [T; $n]) {
50 self.start_values = values;
51 self.start_frame = frame;
52 }
53
54 pub fn set_end(&mut self, frame: u32, values: [T; $n]) {
55 self.end_values = values;
56 self.end_frame = frame;
57 }
58
59 pub fn set_end_values(&mut self, values: [T; $n]) {
60 self.end_values = values;
61 }
62
63 pub fn set_end_frame(&mut self, frame: u32) {
64 self.end_frame = frame;
65 }
66
67 // XXX: Make it return [T; $n] instead, we don’t want to only do f32 here.
68 pub fn values(&self, frame: u32) -> [f32; $n] {
69 if frame + 1 >= self.end_frame {
70 // XXX: skip the last interpolation step.
71 // This bug is replicated from the original game.
72 //self.start_frame = self.end_frame;
73 //self.end_values
74 let mut values: [f32; $n] = [Default::default(); $n];
75 for (i, value) in self.end_values.iter().enumerate() {
76 values[i] = f32::from(*value);
77 }
78 values
79 } else {
80 let mut coeff = (frame - self.start_frame) as f32 / (self.end_frame - self.start_frame) as f32;
81 coeff = self.formula.apply(coeff);
82 let mut values: [f32; $n] = [Default::default(); $n];
83 for (i, (start, end)) in self.start_values.iter().zip(&self.end_values).enumerate() {
84 values[i] = f32::from(*start + T::from(coeff * f32::from(*end - *start)));
85 }
86 values
87 }
88 }
89 }
90 };
91 }
92
93 generate_interpolator!(Interpolator1, 1);
94 generate_interpolator!(Interpolator2, 2);
95 generate_interpolator!(Interpolator3, 3);
96 //generate_interpolator!(Interpolator4, 4);