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use std::rc::Rc;
use truetype::glyph_data::{self, CompositeDescription, GlyphData, SimpleDescription};
use super::mapping::Mapping;
use super::metrics::Metrics;
use crate::builder::Builder;
use crate::case::Case;
use crate::glyph::Glyph;
use crate::{Offset, Result};
pub struct TrueType {
glyph_data: Rc<GlyphData>,
metrics: Rc<Metrics>,
mapping: Rc<Mapping>,
}
impl TrueType {
#[inline]
pub fn new(glyph_data: Rc<GlyphData>, metrics: Rc<Metrics>, mapping: Rc<Mapping>) -> Self {
TrueType {
glyph_data: glyph_data,
metrics: metrics,
mapping: mapping,
}
}
fn draw_glyph(&self, builder: &mut Builder, glyph: &glyph_data::Glyph) -> Result<()> {
use truetype::glyph_data::Description::*;
match &glyph.description {
&Simple(ref description) => draw_simple(builder, description),
&Composite(ref description) => draw_composite(self, builder, description),
}
}
}
impl Case for TrueType {
fn draw(&self, character: char) -> Result<Option<Glyph>> {
let mut builder = Builder::default();
let glyph_index = match self.mapping.find(character) {
Some(glyph_index) => glyph_index,
_ => return Ok(None),
};
let glyph = match self.glyph_data.get(glyph_index as usize) {
Some(glyph) => glyph,
_ => raise!(
"found no data for character {} with glyph {}",
character,
glyph_index,
),
};
builder.set_horizontal_metrics(self.metrics.get(glyph_index));
if let &Some(ref glyph) = glyph {
self.draw_glyph(&mut builder, glyph)?;
builder.set_bounding_box((glyph.min_x, glyph.min_y, glyph.max_x, glyph.max_y));
}
Ok(Some(builder.into()))
}
}
fn draw_simple(builder: &mut Builder, description: &SimpleDescription) -> Result<()> {
macro_rules! expect(
($condition:expr) => (
if !$condition {
raise!(concat!("found a malformed glyph (", stringify!($condition), ")"));
}
)
);
let &SimpleDescription {
ref end_points,
ref flags,
ref x,
ref y,
..
} = description;
let point_count = flags.len();
expect!(point_count == x.len());
expect!(point_count == y.len());
let mut i = 0;
let mut sum = Offset::default();
for k in end_points.iter().map(|&k| k as usize) {
expect!(i < point_count);
let start = Offset::from((x[i], y[i]));
let mut control = match flags[i].is_on_curve() {
false => Some(Offset::default()),
_ => None,
};
let mut sum_delta = start;
let mut offset = Offset::default();
for j in (i + 1)..=k {
expect!(j < point_count);
let current = (x[j], y[j]).into();
sum_delta += current;
match (flags[j].is_on_curve(), &mut control) {
(false, control @ &mut None) => {
*control = Some(current);
}
(false, &mut Some(ref mut control)) => {
let current = current / 2.0;
builder.add_quadratic(*control, current);
offset += *control + current;
*control = current;
}
(true, &mut None) => {
builder.add_linear(current);
offset += current;
}
(true, control @ &mut Some(_)) => {
let control = control.take().unwrap();
builder.add_quadratic(control, current);
offset += control + current;
}
}
}
match (flags[i].is_on_curve(), control) {
(false, None) => {
let control = (sum + start) - (sum + sum_delta);
builder.move_control(control);
offset += control;
builder.move_absolute(sum + sum_delta);
}
(false, Some(control)) => {
let current = ((sum + start) - (sum + sum_delta)) / 2.0;
if !control.is_zero() || !current.is_zero() {
builder.add_quadratic(control, current);
}
offset += control + current;
builder.move_control(current);
offset += current;
builder.move_absolute(sum + sum_delta + current);
}
(true, None) => {
let current = -offset;
if !current.is_zero() {
builder.add_linear(current);
}
offset += current;
builder.move_absolute(sum + start);
}
(true, Some(control)) => {
let current = -offset - control;
if !control.is_zero() || !current.is_zero() {
builder.add_quadratic(control, current);
}
offset += control + current;
builder.move_absolute(sum + start);
}
}
debug_assert!(offset.is_zero());
builder.flush();
sum += sum_delta;
i = k + 1;
}
Ok(())
}
fn draw_composite(
case: &TrueType,
builder: &mut Builder,
description: &CompositeDescription,
) -> Result<()> {
use truetype::glyph_data::{Arguments, Options};
for component in description.components.iter() {
let glyph_index = component.glyph_index;
let offset = match &component.arguments {
&Arguments::Offsets(x, y) => Offset::from((x, y)),
&Arguments::Indices(..) => unimplemented!(),
};
match &component.options {
&Options::None => {}
&Options::Scalar(..) => unimplemented!(),
&Options::Vector(..) => unimplemented!(),
&Options::Matrix(..) => unimplemented!(),
}
let glyph = match case.glyph_data.get(glyph_index as usize) {
Some(&Some(ref glyph)) => glyph,
Some(&None) => continue,
_ => raise!("found no data for glyph index {}", glyph_index),
};
if component.flags.should_use_metrics() {
builder.set_horizontal_metrics(case.metrics.get(glyph_index));
}
builder.nest(offset, |builder| case.draw_glyph(builder, glyph))?;
}
Ok(())
}