usvg/tree/
geom.rs

1// Copyright 2018 the Resvg Authors
2// SPDX-License-Identifier: Apache-2.0 OR MIT
3
4use strict_num::ApproxEqUlps;
5use svgtypes::{Align, AspectRatio};
6pub use tiny_skia_path::{NonZeroRect, Rect, Size, Transform};
7
8/// Approximate zero equality comparisons.
9pub trait ApproxZeroUlps: ApproxEqUlps {
10    /// Checks if the number is approximately zero.
11    fn approx_zero_ulps(&self, ulps: <Self::Flt as strict_num::Ulps>::U) -> bool;
12}
13
14impl ApproxZeroUlps for f32 {
15    fn approx_zero_ulps(&self, ulps: i32) -> bool {
16        self.approx_eq_ulps(&0.0, ulps)
17    }
18}
19
20impl ApproxZeroUlps for f64 {
21    fn approx_zero_ulps(&self, ulps: i64) -> bool {
22        self.approx_eq_ulps(&0.0, ulps)
23    }
24}
25
26/// Checks that the current number is > 0.
27pub(crate) trait IsValidLength {
28    /// Checks that the current number is > 0.
29    fn is_valid_length(&self) -> bool;
30}
31
32impl IsValidLength for f32 {
33    #[inline]
34    fn is_valid_length(&self) -> bool {
35        *self > 0.0 && self.is_finite()
36    }
37}
38
39impl IsValidLength for f64 {
40    #[inline]
41    fn is_valid_length(&self) -> bool {
42        *self > 0.0 && self.is_finite()
43    }
44}
45
46/// View box.
47#[derive(Clone, Copy, Debug)]
48pub(crate) struct ViewBox {
49    /// Value of the `viewBox` attribute.
50    pub rect: NonZeroRect,
51
52    /// Value of the `preserveAspectRatio` attribute.
53    pub aspect: AspectRatio,
54}
55
56impl ViewBox {
57    /// Converts `viewBox` into `Transform`.
58    pub fn to_transform(&self, img_size: Size) -> Transform {
59        let vr = self.rect;
60
61        let sx = img_size.width() / vr.width();
62        let sy = img_size.height() / vr.height();
63
64        let (sx, sy) = if self.aspect.align == Align::None {
65            (sx, sy)
66        } else {
67            let s = if self.aspect.slice {
68                if sx < sy { sy } else { sx }
69            } else {
70                if sx > sy { sy } else { sx }
71            };
72
73            (s, s)
74        };
75
76        let x = -vr.x() * sx;
77        let y = -vr.y() * sy;
78        let w = img_size.width() - vr.width() * sx;
79        let h = img_size.height() - vr.height() * sy;
80
81        let (tx, ty) = aligned_pos(self.aspect.align, x, y, w, h);
82        Transform::from_row(sx, 0.0, 0.0, sy, tx, ty)
83    }
84}
85
86/// A bounding box calculator.
87#[derive(Clone, Copy, Debug)]
88pub(crate) struct BBox {
89    left: f32,
90    top: f32,
91    right: f32,
92    bottom: f32,
93}
94
95impl From<Rect> for BBox {
96    fn from(r: Rect) -> Self {
97        Self {
98            left: r.left(),
99            top: r.top(),
100            right: r.right(),
101            bottom: r.bottom(),
102        }
103    }
104}
105
106impl From<NonZeroRect> for BBox {
107    fn from(r: NonZeroRect) -> Self {
108        Self {
109            left: r.left(),
110            top: r.top(),
111            right: r.right(),
112            bottom: r.bottom(),
113        }
114    }
115}
116
117impl Default for BBox {
118    fn default() -> Self {
119        Self {
120            left: f32::MAX,
121            top: f32::MAX,
122            right: f32::MIN,
123            bottom: f32::MIN,
124        }
125    }
126}
127
128impl BBox {
129    /// Checks if the bounding box is default, i.e. invalid.
130    pub fn is_default(&self) -> bool {
131        self.left == f32::MAX
132            && self.top == f32::MAX
133            && self.right == f32::MIN
134            && self.bottom == f32::MIN
135    }
136
137    /// Expand the bounding box to the specified bounds.
138    #[must_use]
139    pub fn expand(&self, r: impl Into<Self>) -> Self {
140        self.expand_impl(r.into())
141    }
142
143    fn expand_impl(&self, r: Self) -> Self {
144        Self {
145            left: self.left.min(r.left),
146            top: self.top.min(r.top),
147            right: self.right.max(r.right),
148            bottom: self.bottom.max(r.bottom),
149        }
150    }
151
152    /// Converts a bounding box into [`Rect`].
153    pub fn to_rect(&self) -> Option<Rect> {
154        if !self.is_default() {
155            Rect::from_ltrb(self.left, self.top, self.right, self.bottom)
156        } else {
157            None
158        }
159    }
160
161    /// Converts a bounding box into [`NonZeroRect`].
162    pub fn to_non_zero_rect(&self) -> Option<NonZeroRect> {
163        if !self.is_default() {
164            NonZeroRect::from_ltrb(self.left, self.top, self.right, self.bottom)
165        } else {
166            None
167        }
168    }
169}
170
171/// Returns object aligned position.
172pub(crate) fn aligned_pos(align: Align, x: f32, y: f32, w: f32, h: f32) -> (f32, f32) {
173    match align {
174        Align::None => (x, y),
175        Align::XMinYMin => (x, y),
176        Align::XMidYMin => (x + w / 2.0, y),
177        Align::XMaxYMin => (x + w, y),
178        Align::XMinYMid => (x, y + h / 2.0),
179        Align::XMidYMid => (x + w / 2.0, y + h / 2.0),
180        Align::XMaxYMid => (x + w, y + h / 2.0),
181        Align::XMinYMax => (x, y + h),
182        Align::XMidYMax => (x + w / 2.0, y + h),
183        Align::XMaxYMax => (x + w, y + h),
184    }
185}
usvg/tree/geom.rs

usvg/tree/
geom.rs
