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

mod argstack;
pub mod cff1;
#[cfg(feature = "variable-fonts")]
pub mod cff2;
mod charset;
mod charstring;
mod dict;
mod encoding;
mod index;
#[cfg(feature = "glyph-names")]
mod std_names;

use core::convert::TryFrom;

use crate::parser::{FromData, TryNumFrom};
use crate::{OutlineBuilder, RectF};

/// A list of errors that can occur during a CFF glyph outlining.
#[allow(missing_docs)]
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum CFFError {
    NoGlyph,
    ReadOutOfBounds,
    ZeroBBox,
    InvalidOperator,
    UnsupportedOperator,
    MissingEndChar,
    DataAfterEndChar,
    NestingLimitReached,
    ArgumentsStackLimitReached,
    InvalidArgumentsStackLength,
    BboxOverflow,
    MissingMoveTo,
    InvalidSubroutineIndex,
    NoLocalSubroutines,
    InvalidSeacCode,
    #[cfg(feature = "variable-fonts")]
    InvalidItemVariationDataIndex,
    #[cfg(feature = "variable-fonts")]
    InvalidNumberOfBlendOperands,
    #[cfg(feature = "variable-fonts")]
    BlendRegionsLimitReached,
}

pub(crate) struct Builder<'a> {
    builder: &'a mut dyn OutlineBuilder,
    bbox: RectF,
}

impl<'a> Builder<'a> {
    #[inline]
    fn move_to(&mut self, x: f32, y: f32) {
        self.bbox.extend_by(x, y);
        self.builder.move_to(x, y);
    }

    #[inline]
    fn line_to(&mut self, x: f32, y: f32) {
        self.bbox.extend_by(x, y);
        self.builder.line_to(x, y);
    }

    #[inline]
    fn curve_to(&mut self, x1: f32, y1: f32, x2: f32, y2: f32, x: f32, y: f32) {
        self.bbox.extend_by(x1, y1);
        self.bbox.extend_by(x2, y2);
        self.bbox.extend_by(x, y);
        self.builder.curve_to(x1, y1, x2, y2, x, y);
    }

    #[inline]
    fn close(&mut self) {
        self.builder.close();
    }
}

/// A type-safe wrapper for string ID.
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Debug)]
pub struct StringId(u16);

impl FromData for StringId {
    const SIZE: usize = 2;

    #[inline]
    fn parse(data: &[u8]) -> Option<Self> {
        u16::parse(data).map(StringId)
    }
}

pub trait IsEven {
    fn is_even(&self) -> bool;
    fn is_odd(&self) -> bool;
}

impl IsEven for usize {
    #[inline]
    fn is_even(&self) -> bool {
        (*self) & 1 == 0
    }

    #[inline]
    fn is_odd(&self) -> bool {
        !self.is_even()
    }
}

#[cfg(feature = "std")]
#[inline]
pub fn f32_abs(n: f32) -> f32 {
    n.abs()
}

#[cfg(not(feature = "std"))]
#[inline]
pub fn f32_abs(n: f32) -> f32 {
    if n.is_sign_negative() {
        -n
    } else {
        n
    }
}

#[inline]
pub fn conv_subroutine_index(index: f32, bias: u16) -> Result<u32, CFFError> {
    conv_subroutine_index_impl(index, bias).ok_or(CFFError::InvalidSubroutineIndex)
}

#[inline]
fn conv_subroutine_index_impl(index: f32, bias: u16) -> Option<u32> {
    let index = i32::try_num_from(index)?;
    let bias = i32::from(bias);

    let index = index.checked_add(bias)?;
    u32::try_from(index).ok()
}

// Adobe Technical Note #5176, Chapter 16 "Local / Global Subrs INDEXes"
#[inline]
pub fn calc_subroutine_bias(len: u32) -> u16 {
    if len < 1240 {
        107
    } else if len < 33900 {
        1131
    } else {
        32768
    }
}