harfrust/hb/
ot_shape_plan.rs

1use alloc::boxed::Box;
2use core::any::Any;
3use smallvec::SmallVec;
4
5use crate::hb::common::HB_FEATURE_GLOBAL_END;
6use crate::hb::common::HB_FEATURE_GLOBAL_START;
7use crate::ShaperInstance;
8
9use super::aat::map::*;
10use super::ot_map::*;
11use super::ot_shape::*;
12use super::ot_shaper::*;
13use super::{hb_font_t, hb_mask_t, Direction, Feature, Language, Script};
14
15/// A reusable plan for shaping a text buffer.
16pub struct hb_ot_shape_plan_t {
17    pub(crate) direction: Direction,
18    pub(crate) script: Option<Script>,
19    pub(crate) language: Option<Language>,
20    pub(crate) shaper: &'static hb_ot_shaper_t,
21    pub(crate) ot_map: hb_ot_map_t,
22    pub(crate) aat_map: AatMap,
23    pub(crate) data: Option<Box<dyn Any + Send + Sync>>,
24
25    pub(crate) frac_mask: hb_mask_t,
26    pub(crate) numr_mask: hb_mask_t,
27    pub(crate) dnom_mask: hb_mask_t,
28    pub(crate) rtlm_mask: hb_mask_t,
29    pub(crate) kern_mask: hb_mask_t,
30
31    pub(crate) requested_kerning: bool,
32    pub(crate) has_frac: bool,
33    pub(crate) has_vert: bool,
34    pub(crate) has_gpos_mark: bool,
35    pub(crate) zero_marks: bool,
36    pub(crate) fallback_glyph_classes: bool,
37    pub(crate) fallback_mark_positioning: bool,
38    pub(crate) adjust_mark_positioning_when_zeroing: bool,
39
40    pub(crate) apply_gpos: bool,
41    pub(crate) apply_fallback_kern: bool,
42    pub(crate) apply_kern: bool,
43    pub(crate) apply_kerx: bool,
44    pub(crate) apply_morx: bool,
45    pub(crate) apply_trak: bool,
46
47    pub(crate) user_features: SmallVec<[Feature; 4]>,
48}
49
50pub trait AnyFont {
51    fn with_font<F, R>(&self, f: F) -> R
52    where
53        F: FnOnce(Option<&hb_font_t>) -> R;
54}
55
56impl AnyFont for hb_font_t<'_> {
57    fn with_font<F, R>(&self, f: F) -> R
58    where
59        F: FnOnce(Option<&hb_font_t>) -> R,
60    {
61        f(Some(self))
62    }
63}
64
65impl AnyFont for crate::font::FontInstance {
66    fn with_font<F, R>(&self, f: F) -> R
67    where
68        F: FnOnce(Option<&hb_font_t>) -> R,
69    {
70        let hb_font = hb_font_t::from_font(self);
71        f(hb_font.as_ref())
72    }
73}
74
75impl hb_ot_shape_plan_t {
76    /// Returns a plan that can be used for shaping any buffer with the
77    /// provided properties.
78    pub fn new(
79        font: &impl AnyFont,
80        direction: Direction,
81        script: Option<Script>,
82        language: Option<&Language>,
83        user_features: &[Feature],
84    ) -> Self {
85        assert_ne!(
86            direction,
87            Direction::Invalid,
88            "Direction must not be Invalid"
89        );
90        font.with_font(|font| {
91            let font = font.expect("font should be available for shaping");
92            let mut planner = hb_ot_shape_planner_t::new(font, direction, script, language);
93            planner.collect_features(user_features);
94            planner.compile(user_features)
95        })
96    }
97
98    pub(crate) fn data<T: 'static>(&self) -> &T {
99        self.data.as_ref().unwrap().downcast_ref().unwrap()
100    }
101
102    /// The direction of the text.
103    pub fn direction(&self) -> Direction {
104        self.direction
105    }
106
107    /// The script of the text.
108    pub fn script(&self) -> Option<Script> {
109        self.script
110    }
111
112    /// The language of the text.
113    pub fn language(&self) -> Option<&Language> {
114        self.language.as_ref()
115    }
116}
117
118/// A key used for selecting a shape plan.
119pub struct ShapePlanKey<'a> {
120    script: Option<Script>,
121    direction: Direction,
122    language: Option<&'a Language>,
123    feature_variations: [Option<u32>; 2],
124    features: &'a [Feature],
125}
126
127impl<'a> ShapePlanKey<'a> {
128    /// Creates a new shape plan key with the given script and direction.
129    pub fn new(script: Option<Script>, direction: Direction) -> Self {
130        Self {
131            script,
132            direction,
133            language: None,
134            feature_variations: [None; 2],
135            features: &[],
136        }
137    }
138
139    /// Sets the language to use for this shape plan key.
140    pub fn language(mut self, language: Option<&'a Language>) -> Self {
141        self.language = language;
142        self
143    }
144
145    /// Sets the instance to use for this shape plan key.
146    pub fn instance(mut self, instance: Option<&ShaperInstance>) -> Self {
147        self.feature_variations = instance
148            .map(|instance| instance.feature_variations)
149            .unwrap_or_default();
150        self
151    }
152
153    /// Sets the features to use for this shape plan key.
154    pub fn features(mut self, features: &'a [Feature]) -> Self {
155        self.features = features;
156        self
157    }
158
159    /// Returns true if this key is a match for the given shape plan.
160    pub fn matches(&self, plan: &hb_ot_shape_plan_t) -> bool {
161        self.script == plan.script
162            && self.direction == plan.direction
163            && self.language == plan.language.as_ref()
164            && self.feature_variations == *plan.ot_map.feature_variations()
165            && features_equivalent(self.features, &plan.user_features)
166    }
167}
168
169fn features_equivalent(features_a: &[Feature], features_b: &[Feature]) -> bool {
170    if features_a.len() != features_b.len() {
171        return false;
172    }
173    for (a, b) in features_a.iter().zip(features_b) {
174        if a.tag != b.tag
175            || a.value != b.value
176            || (a.start == HB_FEATURE_GLOBAL_START && a.end == HB_FEATURE_GLOBAL_END)
177                != (b.start == HB_FEATURE_GLOBAL_START && b.end == HB_FEATURE_GLOBAL_END)
178        {
179            return false;
180        }
181    }
182    true
183}
184
185#[cfg(test)]
186mod tests {
187    use super::hb_ot_shape_plan_t;
188
189    #[test]
190    fn test_shape_plan_is_send_and_sync() {
191        fn ensure_send_and_sync<T: Send + Sync>() {}
192        ensure_send_and_sync::<hb_ot_shape_plan_t>();
193    }
194}
harfrust/hb/ot_shape_plan.rs

harfrust/hb/
ot_shape_plan.rs
