1 files changed, 25 insertions, 0 deletions
diff --git a/src/font/mod.rs b/src/font/mod.rs
index bedc107d..94ec170e 100644
--- a/src/font/mod.rs
+++ b/src/font/mod.rs
@@ -12,6 +12,7 @@ use std::sync::Arc;
 
 use ttf_parser::GlyphId;
 
+use crate::eval::{cast_from_value, cast_to_value, Value};
 use crate::geom::Em;
 use crate::util::Buffer;
 
@@ -249,3 +250,27 @@ pub enum VerticalFontMetric {
     /// present and falls back to the descender from the `hhea` table otherwise.
     Descender,
 }
+
+cast_from_value! {
+    VerticalFontMetric,
+    /// The font's ascender, which typically exceeds the height of all glyphs.
+    "ascender" => Self::Ascender,
+    /// The approximate height of uppercase letters.
+    "cap-height" => Self::CapHeight,
+    /// The approximate height of non-ascending lowercase letters.
+    "x-height" => Self::XHeight,
+    /// The baseline on which the letters rest.
+    "baseline" => Self::Baseline,
+    /// The font's ascender, which typically exceeds the depth of all glyphs.
+    "descender" => Self::Descender,
+}
+
+cast_to_value! {
+    v: VerticalFontMetric => Value::from(match v {
+        VerticalFontMetric::Ascender => "ascender",
+        VerticalFontMetric::CapHeight => "cap-height",
+        VerticalFontMetric::XHeight => "x-height",
+        VerticalFontMetric::Baseline => "baseline" ,
+        VerticalFontMetric::Descender => "descender",
+    })
+}