diff --git a/crates/text/src/variable.rs b/crates/text/src/variable.rs index 6594e2dc..a673578e 100644 --- a/crates/text/src/variable.rs +++ b/crates/text/src/variable.rs @@ -197,26 +197,53 @@ mod tests { eprintln!("no variable font installed: skipped"); return; }; - // An axis that changes widths (wdth or wght, else the first that moves). - let a = axes.iter().find(|a| a.tag == "wdth" && a.max > a.min).or_else(|| axes.iter().find(|a| a.tag == "wght" && a.max > a.min)).unwrap_or(&axes[0]); let info = crate::fonts::face(face).info.clone(); - let st = |v: f32| crate::TextStyle { + // An axis that moves the advance: `wdth` and `wght` usually do, but a monospaced family + // keeps its advances fixed along `wght` (Google Sans Code does) and moves them along its + // own axis instead, so try the axes in order and take the first one that moves. A face + // with no axis carrying a range is the only case that skips: a variation path that broke + // completely moves neither the advances nor the outlines, and that has to fail below. + let st = |a: &FontAxis, v: f32| crate::TextStyle { family: info.family.clone(), style: info.style.clone(), size: 100.0, variations: vec![(a.tag.clone(), v)], ..Default::default() }; - let (lo, hi) = (crate::layout::measure("Hamburgefonts", &st(a.min)), crate::layout::measure("Hamburgefonts", &st(a.max))); + let ranged: Vec<&FontAxis> = axes.iter().filter(|a| a.max > a.min).collect(); + if ranged.is_empty() { + eprintln!("no variable axis installed here carries a range: skipped"); + return; + } + let mut moving = None; + for a in &ranged { + let (lo, hi) = (crate::layout::measure("Hamburgefonts", &st(a, a.min)), crate::layout::measure("Hamburgefonts", &st(a, a.max))); + if (lo - hi).abs() > 1.0 { + moving = Some(((*a).clone(), lo, hi)); + break; + } + } if crate::resolve(&info.family, &info.style).face != face { eprintln!("variable face not reachable by family/style: skipped"); return; } - assert!((lo - hi).abs() > 1.0, "{} {}..{}: advances {lo} vs {hi}", a.tag, a.min, a.max); - let ink = |v: f32| { - let l = crate::layout::layout("H", &st(v), &crate::ParagraphStyle::default()); + let ink = |a: &FontAxis, v: f32| { + let l = crate::layout::layout("H", &st(a, v), &crate::ParagraphStyle::default()); l.glyphs.iter().map(|g| crate::glyph_outline(g).area().abs()).sum::() }; - assert!((ink(a.min) - ink(a.max)).abs() > 1.0); + if let Some((a, lo, hi)) = moving { + // The axis was picked because it moves the advance; the outline has to follow it too. + assert!((lo - hi).abs() > 1.0, "{} {}..{}: advances {lo} vs {hi}", a.tag, a.min, a.max); + let (i_lo, i_hi) = (ink(&a, a.min), ink(&a, a.max)); + assert!((i_lo - i_hi).abs() > 1.0, "{} {}..{}: outlines do not move", a.tag, a.min, a.max); + } else { + // Nothing here moves an advance. Holding the advances is what a monospaced family does + // on purpose, but it is also what a broken variation path does, so this case still has + // to fail rather than skip: the outline must move along `wght`, or, on a face without + // one, along the first axis that carries a range. + let a = axes.iter().find(|a| a.tag == "wght" && a.max > a.min).unwrap_or(ranged[0]); + let (i_lo, i_hi) = (ink(a, a.min), ink(a, a.max)); + assert!((i_lo - i_hi).abs() > 1.0, "{} {}..{}: neither the advances nor the outlines move, so variation support looks broken", a.tag, a.min, a.max); + } } }