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use fontdue::FontSettings;
use geom::Geometry;
use glam::Vec2;
use ordered_float::OrderedFloat;
use std::ops::{Deref, DerefMut};
use ttf_parser::{Face, Rect};
pub use fontdue::{Metrics, OutlineBounds};
mod geom;
mod math;
#[derive(Debug, Clone)]
pub struct Font {
glyphs: Vec<(Geometry, Rect)>,
oo_units_per_em: f32,
inner: fontdue::Font,
}
struct InternalMetrics {
sf: f32,
radius: usize,
offset_x: f32,
offset_y: f32,
width: usize,
height: usize,
}
impl Font {
pub fn from_bytes(bytes: &[u8]) -> Result<Self, &'static str> {
let inner = fontdue::Font::from_bytes(bytes, FontSettings::default())?;
let face = Face::from_slice(bytes, 0).unwrap();
let oo_units_per_em = 1.0 / face.units_per_em() as f32;
let initial = (
Geometry::new(),
Rect {
x_min: 0,
y_min: 0,
x_max: 0,
y_max: 0,
},
);
let mut glyphs = vec![initial; face.number_of_glyphs() as usize];
for (&c, &i) in inner.chars().iter() {
(|| {
let mut geom = Geometry::new();
let bb = face.outline_glyph(face.glyph_index(c)?, &mut geom)?;
glyphs[i.get() as usize] = (geom, bb);
Some(())
})();
}
Ok(Self {
glyphs,
oo_units_per_em,
inner,
})
}
pub fn scale_factor(&self, px: f32) -> f32 {
px * self.oo_units_per_em
}
pub fn radius(&self, px: f32) -> usize {
let scale_factor = self.scale_factor(px);
(128.0 * scale_factor).ceil() as _
}
pub fn metrics_sdf(&self, character: char, px: f32) -> Metrics {
self.metrics_indexed_sdf(self.lookup_glyph_index(character), px)
}
pub fn metrics_indexed_sdf(&self, index: u16, px: f32) -> Metrics {
let (_, bb) = self.glyphs.get(index as usize).unwrap();
let metrics = self.internal_metrics(px, bb);
self.modify_metrics(index, px, metrics.radius, metrics.width, metrics.height)
}
pub fn rasterize_sdf(&self, character: char, px: f32) -> (Metrics, Vec<u8>) {
self.rasterize_indexed_sdf(self.lookup_glyph_index(character), px)
}
pub fn rasterize_indexed_sdf(&self, index: u16, px: f32) -> (Metrics, Vec<u8>) {
let (geom, bb) = self.glyphs.get(index as usize).unwrap();
let metrics = self.internal_metrics(px, bb);
let image = (0..metrics.height)
.rev()
.flat_map(|y| (0..metrics.width).map(move |x| (x, y)))
.map(|(x, y)| {
Vec2::new(
x as f32 - metrics.radius as f32 + metrics.offset_x,
y as f32 - metrics.radius as f32 + metrics.offset_y,
) / metrics.sf
})
.map(|p| {
let is_inside = geom.is_inside(p);
let mut x = geom
.iter_lines()
.map(move |s| s.distance(p))
.map(OrderedFloat)
.min()
.unwrap_or(OrderedFloat(0.0))
.0;
if !is_inside {
x *= -1.0;
}
(x + 128.0) as u8
})
.collect();
(
self.modify_metrics(index, px, metrics.radius, metrics.width, metrics.height),
image,
)
}
fn internal_metrics(&self, px: f32, bb: &Rect) -> InternalMetrics {
let sf = self.scale_factor(px);
let radius = self.radius(px);
let offset_x = bb.x_min as f32 * sf;
let offset_y = bb.y_min as f32 * sf;
InternalMetrics {
sf,
radius,
offset_x,
offset_y,
width: (bb.x_max as f32 * sf - offset_x) as usize + radius * 2,
height: (bb.y_max as f32 * sf - offset_y) as usize + radius * 2,
}
}
fn modify_metrics(
&self,
index: u16,
px: f32,
radius: usize,
width: usize,
height: usize,
) -> Metrics {
let mut metrics = self.inner.metrics_indexed(index, px);
metrics.xmin -= radius as i32;
metrics.ymin -= radius as i32;
metrics.width = width;
metrics.height = height;
metrics
}
}
impl Deref for Font {
type Target = fontdue::Font;
fn deref(&self) -> &Self::Target {
&self.inner
}
}
impl DerefMut for Font {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.inner
}
}
