use alloc::{string::String, vec::Vec};
use core::fmt::{self, Write};
pub trait OutlinePen {
fn move_to(&mut self, x: f32, y: f32);
fn line_to(&mut self, x: f32, y: f32);
fn quad_to(&mut self, cx0: f32, cy0: f32, x: f32, y: f32);
fn curve_to(&mut self, cx0: f32, cy0: f32, cx1: f32, cy1: f32, x: f32, y: f32);
fn close(&mut self);
}
#[derive(Copy, Clone, PartialEq, PartialOrd, Debug)]
pub enum PathElement {
MoveTo { x: f32, y: f32 },
LineTo { x: f32, y: f32 },
QuadTo { cx0: f32, cy0: f32, x: f32, y: f32 },
CurveTo {
cx0: f32,
cy0: f32,
cx1: f32,
cy1: f32,
x: f32,
y: f32,
},
Close,
}
#[derive(Debug, Default, Copy, Clone)]
pub enum PathStyle {
#[default]
FreeType,
HarfBuzz,
}
impl OutlinePen for Vec<PathElement> {
fn move_to(&mut self, x: f32, y: f32) {
self.push(PathElement::MoveTo { x, y })
}
fn line_to(&mut self, x: f32, y: f32) {
self.push(PathElement::LineTo { x, y })
}
fn quad_to(&mut self, cx0: f32, cy0: f32, x: f32, y: f32) {
self.push(PathElement::QuadTo { cx0, cy0, x, y })
}
fn curve_to(&mut self, cx0: f32, cy0: f32, cx1: f32, cy1: f32, x: f32, y: f32) {
self.push(PathElement::CurveTo {
cx0,
cy0,
cx1,
cy1,
x,
y,
})
}
fn close(&mut self) {
self.push(PathElement::Close)
}
}
pub struct NullPen;
impl OutlinePen for NullPen {
fn move_to(&mut self, _x: f32, _y: f32) {}
fn line_to(&mut self, _x: f32, _y: f32) {}
fn quad_to(&mut self, _cx0: f32, _cy0: f32, _x: f32, _y: f32) {}
fn curve_to(&mut self, _cx0: f32, _cy0: f32, _cx1: f32, _cy1: f32, _x: f32, _y: f32) {}
fn close(&mut self) {}
}
#[derive(Clone, Default, Debug)]
pub struct SvgPen(String, Option<usize>);
impl SvgPen {
pub fn new() -> Self {
Self::default()
}
pub fn with_precision(precision: usize) -> Self {
Self(String::default(), Some(precision))
}
pub fn clear(&mut self) {
self.0.clear();
}
fn maybe_push_space(&mut self) {
if !self.0.is_empty() {
self.0.push(' ');
}
}
}
impl core::ops::Deref for SvgPen {
type Target = str;
fn deref(&self) -> &Self::Target {
self.0.as_str()
}
}
impl OutlinePen for SvgPen {
fn move_to(&mut self, x: f32, y: f32) {
self.maybe_push_space();
let _ = if let Some(prec) = self.1 {
write!(self.0, "M{x:.0$},{y:.0$}", prec)
} else {
write!(self.0, "M{x},{y}")
};
}
fn line_to(&mut self, x: f32, y: f32) {
self.maybe_push_space();
let _ = if let Some(prec) = self.1 {
write!(self.0, "L{x:.0$},{y:.0$}", prec)
} else {
write!(self.0, "L{x},{y}")
};
}
fn quad_to(&mut self, cx0: f32, cy0: f32, x: f32, y: f32) {
self.maybe_push_space();
let _ = if let Some(prec) = self.1 {
write!(self.0, "Q{cx0:.0$},{cy0:.0$} {x:.0$},{y:.0$}", prec)
} else {
write!(self.0, "Q{cx0},{cy0} {x},{y}")
};
}
fn curve_to(&mut self, cx0: f32, cy0: f32, cx1: f32, cy1: f32, x: f32, y: f32) {
self.maybe_push_space();
let _ = if let Some(prec) = self.1 {
write!(
self.0,
"C{cx0:.0$},{cy0:.0$} {cx1:.0$},{cy1:.0$} {x:.0$},{y:.0$}",
prec
)
} else {
write!(self.0, "C{cx0},{cy0} {cx1},{cy1} {x},{y}")
};
}
fn close(&mut self) {
self.maybe_push_space();
self.0.push('Z');
}
}
impl AsRef<str> for SvgPen {
fn as_ref(&self) -> &str {
self.0.as_ref()
}
}
impl From<String> for SvgPen {
fn from(value: String) -> Self {
Self(value, None)
}
}
impl From<SvgPen> for String {
fn from(value: SvgPen) -> Self {
value.0
}
}
impl fmt::Display for SvgPen {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.0)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn svg_pen_precision() {
let svg_data = [None, Some(1), Some(4)].map(|prec| {
let mut pen = match prec {
None => SvgPen::new(),
Some(prec) => SvgPen::with_precision(prec),
};
pen.move_to(1.0, 2.45556);
pen.line_to(1.2, 4.0);
pen.quad_to(2.0345, 3.56789, -0.157, -425.07);
pen.curve_to(-37.0010, 4.5, 2.0, 1.0, -0.5, -0.25);
pen.close();
pen.to_string()
});
let expected = [
"M1,2.45556 L1.2,4 Q2.0345,3.56789 -0.157,-425.07 C-37.001,4.5 2,1 -0.5,-0.25 Z",
"M1.0,2.5 L1.2,4.0 Q2.0,3.6 -0.2,-425.1 C-37.0,4.5 2.0,1.0 -0.5,-0.2 Z",
"M1.0000,2.4556 L1.2000,4.0000 Q2.0345,3.5679 -0.1570,-425.0700 C-37.0010,4.5000 2.0000,1.0000 -0.5000,-0.2500 Z"
];
for (result, expected) in svg_data.iter().zip(&expected) {
assert_eq!(result, expected);
}
}
}