From d77396a6ec6aaa7db61a1c09c0bb9c3399385941 Mon Sep 17 00:00:00 2001
From: lauchmelder <robert.altner@einweckglas.com>
Date: Sun, 2 Mar 2025 20:05:50 +0100
Subject: [PATCH] add font header table

---
 src/font.rs             |  7 +++++
 src/font/font_header.rs | 62 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)
 create mode 100644 src/font/font_header.rs

diff --git a/src/font.rs b/src/font.rs
index 82bb366..5fc6648 100644
--- a/src/font.rs
+++ b/src/font.rs
@@ -1,12 +1,14 @@
 mod table_directory;
 mod character_map;
 mod maximum_profile;
+mod font_header;
 mod search;
 
 use std::{fs::File, io::{BufReader, Read}};
 
 use bincode::Options;
 use character_map::CharacterMap;
+use font_header::FontHeader;
 use log::{debug, info};
 use maximum_profile::MaximumProfile;
 use table_directory::TableDirectory;
@@ -18,6 +20,7 @@ fn deserialize<R: Read, T: serde::de::DeserializeOwned>(reader: R) -> bincode::R
 #[derive(Debug)]
 pub struct Font {
 	table_directory: TableDirectory,
+	font_header: FontHeader,
 	character_map: CharacterMap,
 	maximum_profile: MaximumProfile
 }
@@ -27,6 +30,9 @@ impl Font {
 		let mut buf_reader = BufReader::new(file.try_clone()?);
 		let table_directory = TableDirectory::new(&mut buf_reader)?;
 
+		let font_header = table_directory.get_table(&file)?;
+		debug!("{font_header:#?}");
+
 		let character_map = table_directory.get_table(&file)?;
 		debug!("{character_map:#?}");
 
@@ -35,6 +41,7 @@ impl Font {
 
 		Ok(Font {
 			table_directory,
+			font_header,
 			character_map,
 			maximum_profile
 		})
diff --git a/src/font/font_header.rs b/src/font/font_header.rs
new file mode 100644
index 0000000..b7702a7
--- /dev/null
+++ b/src/font/font_header.rs
@@ -0,0 +1,62 @@
+use std::{fs::File, io::BufReader};
+
+use log::warn;
+use serde::Deserialize;
+
+use super::{deserialize, table_directory::{FontTable, TableDirectoryRecord}};
+
+#[derive(Debug, Deserialize, Default)]
+pub struct Version {
+	major: u16,
+	minor: u16
+}
+
+#[derive(Debug, Deserialize)]
+pub struct FontHeader {
+	#[serde(skip)]
+	version: Version,
+	
+	#[serde(skip)]
+	font_revision: Version,
+
+	checksum_adjust: u32,
+	magic_number: u32,
+	flags: u16,
+	units_per_em: u16,
+
+	created: i64,
+	modified: i64,
+
+	xmin: i16,
+	ymin: i16,
+	xmax: i16,
+	ymax: i16,
+
+	mac_style: u16,
+	lowest_rec_ppem: u16,
+
+	font_direction_hint: i16,
+	index_to_loc_hint: i16,
+	glyph_data_format: i16
+}
+
+impl FontTable for FontHeader {
+	const TAG: &'static str = "head";
+
+	fn decode(reader: BufReader<File>, _: &TableDirectoryRecord) -> bincode::Result<Self>
+		where Self: Sized
+	{
+		let version = deserialize::<_, Version>(reader.get_ref())?;
+		if version.major != 1 && version.minor != 0 {
+			warn!("Font version is not 1.0");
+		}
+
+		let font_revision = deserialize::<_, Version>(reader.get_ref())?;
+
+		let mut font_header: FontHeader = deserialize(reader.get_ref())?;
+		font_header.version = version;
+		font_header.font_revision = font_revision;
+
+		Ok(font_header)
+	}
+}