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

// Copyright 2015 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Geometry primitive data structures and manipulations

use std::fmt::{Debug, Formatter, Result};

#[derive(Copy, Clone)]
pub struct Point {
    pub x: f32,
    pub y: f32,
}

impl Point {
    pub fn new<T>(x: T, y: T) -> Point
    where
        T: Into<f32>,
    {
        Point {
            x: x.into(),
            y: y.into(),
        }
    }

    pub fn lerp(t: f32, p0: &Self, p1: &Self) -> Self {
        Point {
            x: p0.x + t * (p1.x - p0.x),
            y: p0.y + t * (p1.y - p0.y),
        }
    }
}

impl Debug for Point {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "({}, {})", self.x, self.y)
    }
}

#[derive(Debug)]
pub struct Affine {
    a: f32,
    b: f32,
    c: f32,
    d: f32,
    e: f32,
    f: f32,
}

impl Affine {
    /// Concatenate two affine transforms.
    pub fn concat(t1: &Affine, t2: &Affine) -> Affine {
        Affine {
            a: t1.a * t2.a + t1.c * t2.b,
            b: t1.b * t2.a + t1.d * t2.b,
            c: t1.a * t2.c + t1.c * t2.d,
            d: t1.b * t2.c + t1.d * t2.d,
            e: t1.a * t2.e + t1.c * t2.f + t1.e,
            f: t1.b * t2.e + t1.d * t2.f + t1.f,
        }
    }
}

pub fn affine_pt(z: &Affine, p: &Point) -> Point {
    Point {
        x: z.a * p.x + z.c * p.y + z.e,
        y: z.b * p.x + z.d * p.y + z.f,
    }
}

gen_new!(Affine, a: f32, b: f32, c: f32, d: f32, e: f32, f: f32);