From 5ef66c10255a94e4bb4d44170b63b16abe4c86a9 Mon Sep 17 00:00:00 2001
From: Orycterope <tvermeilh@gmail.com>
Date: Tue, 7 Aug 2018 15:10:19 +0200
Subject: [PATCH 1/2] hhea table

---
 src/font.rs | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/font.rs b/src/font.rs
index af1cdbc..52ec12a 100644
--- a/src/font.rs
+++ b/src/font.rs
@@ -670,6 +670,26 @@ impl<'a> CompoundGlyph<'a> {
     }
 }
 
+struct Hhea<'a>(&'a [u8]);
+
+impl<'a> Hhea<'a> {
+    fn get_ascent(&self) -> i16 {
+        get_i16(self.0, 4).unwrap()
+    }
+
+    fn get_descent(&self) -> i16 {
+        get_i16(self.0, 6).unwrap()
+    }
+
+    fn get_line_gap(&self) -> i16 {
+        get_i16(self.0, 8).unwrap()
+    }
+
+    fn get_advance_width_max(&self) -> u16 {
+        get_u16(self.0, 10).unwrap()
+    }
+}
+
 pub struct Font<'a> {
     _version: u32,
     _tables: HashMap<Tag, &'a [u8]>,
@@ -677,6 +697,7 @@ pub struct Font<'a> {
     maxp: Maxp<'a>,
     cmap: Option<Cmap<'a>>,
     loca: Option<Loca<'a>>,
+    hhea: Option<Hhea<'a>>,
     glyf: Option<&'a [u8]>,
     encoding_index: Option<u16>,
 }
@@ -826,6 +847,22 @@ impl<'a> Font<'a> {
             None => None,
         }
     }
+
+    pub fn max_descent(&self, font_size: u32) -> Option<i32> {
+        self.hhea.as_ref().map(|hhea| hhea.get_descent() as i32 * font_size as i32 / self.head.units_per_em() as i32)
+    }
+
+    pub fn max_ascent(&self, font_size: u32) -> Option<i32> {
+        self.hhea.as_ref().map(|hhea| hhea.get_ascent() as i32 * font_size as i32 / self.head.units_per_em() as i32)
+    }
+
+    pub fn line_gap(&self, font_size: u32) -> Option<i32> {
+        self.hhea.as_ref().map(|hhea| hhea.get_line_gap() as i32 * font_size as i32 / self.head.units_per_em() as i32)
+    }
+
+    pub fn max_advance_width(&self, font_size: u32) -> Option<u32> {
+        self.hhea.as_ref().map(|hhea| hhea.get_advance_width_max() as u32 * font_size as u32 / self.head.units_per_em() as u32)
+    }
 }
 
 #[derive(Debug)]
@@ -968,6 +1005,7 @@ pub fn parse(data: &[u8]) -> Result<Font, FontError> {
     let loca = tables.get(&Tag::from_str("loca")).map(|&data| Loca(data));
     let glyf = tables.get(&Tag::from_str("glyf")).map(|&data| data);
     let cmap = tables.get(&Tag::from_str("cmap")).map(|&data| Cmap(data));
+    let hhea = tables.get(&Tag::from_str("hhea")).map(|&data| Hhea(data));
     let encoding_index = cmap.as_ref().and_then(|cmap| cmap.find_format_4_encoding());
     let f = Font {
         _version: version,
@@ -975,6 +1013,7 @@ pub fn parse(data: &[u8]) -> Result<Font, FontError> {
         head: head,
         maxp: maxp,
         loca: loca,
+        hhea: hhea,
         cmap: cmap,
         glyf: glyf,
         encoding_index: encoding_index,

From 5412cef6a2abb317ef72910648c52602ce0aadeb Mon Sep 17 00:00:00 2001
From: Orycterope <tvermeilh@gmail.com>
Date: Mon, 10 Dec 2018 13:43:45 +0000
Subject: [PATCH 2/2] hhea doc comments

---
 src/font.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/font.rs b/src/font.rs
index 52ec12a..90e15a9 100644
--- a/src/font.rs
+++ b/src/font.rs
@@ -848,18 +848,22 @@ impl<'a> Font<'a> {
         }
     }
 
+    /// Gets the max descent of the font from the `hhea` table.
     pub fn max_descent(&self, font_size: u32) -> Option<i32> {
         self.hhea.as_ref().map(|hhea| hhea.get_descent() as i32 * font_size as i32 / self.head.units_per_em() as i32)
     }
 
+    /// Gets the max ascent of the font from the `hhea` table.
     pub fn max_ascent(&self, font_size: u32) -> Option<i32> {
         self.hhea.as_ref().map(|hhea| hhea.get_ascent() as i32 * font_size as i32 / self.head.units_per_em() as i32)
     }
 
+    /// Gets the line gap of the font from the `hhea` table.
     pub fn line_gap(&self, font_size: u32) -> Option<i32> {
         self.hhea.as_ref().map(|hhea| hhea.get_line_gap() as i32 * font_size as i32 / self.head.units_per_em() as i32)
     }
 
+    /// Gets the max advance width of the font from the `hhea` table.
     pub fn max_advance_width(&self, font_size: u32) -> Option<u32> {
         self.hhea.as_ref().map(|hhea| hhea.get_advance_width_max() as u32 * font_size as u32 / self.head.units_per_em() as u32)
     }