plotters/style/font/
naive.rs

1use super::{FontData, FontFamily, FontStyle, LayoutBox};
2
3#[derive(Debug, Clone)]
4pub struct FontError;
5
6impl std::fmt::Display for FontError {
7    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
8        write!(fmt, "General Error")?;
9        Ok(())
10    }
11}
12
13impl std::error::Error for FontError {}
14
15#[derive(Clone)]
16pub struct FontDataInternal(String, String);
17
18impl FontData for FontDataInternal {
19    type ErrorType = FontError;
20    fn new(family: FontFamily, style: FontStyle) -> Result<Self, FontError> {
21        Ok(FontDataInternal(
22            family.as_str().into(),
23            style.as_str().into(),
24        ))
25    }
26
27    /// Note: This is only a crude estimatation, since for some backend such as SVG, we have no way to
28    /// know the real size of the text anyway. Thus using font-kit is an overkill and doesn't helps
29    /// the layout.
30    fn estimate_layout(&self, size: f64, text: &str) -> Result<LayoutBox, Self::ErrorType> {
31        let em = size / 1.24 / 1.24;
32        Ok((
33            (0, -em.round() as i32),
34            (
35                (em * 0.7 * text.len() as f64).round() as i32,
36                (em * 0.24).round() as i32,
37            ),
38        ))
39    }
40}
plotters/style/font/naive.rs

plotters/style/font/
naive.rs
