Expose units_per_em and raw face id

src/env/mod.rs

@@ -190,6 +190,19 @@ pub struct FaceId(u32);
 impl FaceId {
     /// A blank initialization value.
     pub const MAX: Self = Self(u32::MAX);
+
+    /// Create a face id from the raw underlying value.
+    ///
+    /// This should only be called with values returned by
+    /// [`into_raw`](Self::into_raw).
+    pub fn from_raw(v: u32) -> Self {
+        Self(v)
+    }
+
+    /// Convert into the raw underlying value.
+    pub fn into_raw(self) -> u32 {
+        self.0
+    }
 }
 
 /// A unique identifier for a loaded resource.

src/font.rs

@@ -69,6 +69,16 @@ impl Face {
         &self.ttf
     }
 
+    /// Get the number of units per em.
+    pub fn units_per_em(&self) -> f64 {
+        self.units_per_em
+    }
+
+    /// Convert from font units to an em length.
+    pub fn to_em(&self, units: impl Into<f64>) -> Em {
+        Em::from_units(units, self.units_per_em)
+    }
+
     /// Look up a vertical metric.
     pub fn vertical_metric(&self, metric: VerticalFontMetric) -> Em {
         match metric {
@@ -79,11 +89,6 @@ impl Face {
             VerticalFontMetric::Descender => self.descender,
         }
     }
-
-    /// Convert from font units to an em length.
-    pub fn to_em(&self, units: impl Into<f64>) -> Em {
-        Em::from_units(units, self.units_per_em)
-    }
 }
 
 /// Identifies a vertical metric of a font.