Use font_types::Tag (#10)

Replace `ttf_parser::Tag` with `font_types::Tag` throughout the code.

scripts/gen-tag-table.py

@@ -869,7 +869,7 @@ def rank_delta(bcp_47, ot):
 
 print('// WARNING: this file was generated by ../scripts/gen-tag-table.py')
 print()
-print('use ttf_parser::Tag;')
+print('use skrifa::raw::types::Tag;')
 print()
 print('pub struct LangTag {')
 print('    pub language: &\'static str,')
@@ -882,8 +882,8 @@ def rank_delta(bcp_47, ot):
 
 def hb_tag(tag):
     if tag == DEFAULT_LANGUAGE_SYSTEM:
-        return 'Tag(0)\t           '
-    return 'Tag::from_bytes(b\"%s%s%s%s\")' % tuple(('%-4s' % tag)[:4])
+        return 'Tag::new(&[0; 4])'
+    return 'Tag::new(b\"%s%s%s%s\")' % tuple(('%-4s' % tag)[:4])
 
 
 def hb_tag2(tag):

src/hb/aat_layout.rs

@@ -393,7 +393,7 @@ impl hb_aat_feature_mapping_t {
         selector_to_disable: u8,
     ) -> Self {
         hb_aat_feature_mapping_t {
-            ot_feature_tag: hb_tag_t::from_bytes(ot_feature_tag),
+            ot_feature_tag: hb_tag_t::new(ot_feature_tag),
             aat_feature_type,
             selector_to_enable,
             selector_to_disable,

src/hb/aat_map.rs

@@ -98,7 +98,7 @@ impl hb_aat_map_builder_t {
     pub fn add_feature(&mut self, face: &hb_font_t, feature: &Feature) -> Option<()> {
         let feat = face.tables().feat?;
 
-        if feature.tag == hb_tag_t::from_bytes(b"aalt") {
+        if feature.tag == hb_tag_t::new(b"aalt") {
             let exposes_feature = feat
                 .names
                 .find(HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_ALTERNATIVES as u16)

src/hb/common.rs

@@ -1,7 +1,7 @@
 use alloc::string::String;
 use core::ops::{Bound, RangeBounds};
 
-use ttf_parser::Tag;
+use skrifa::raw::types::Tag;
 
 use super::text_parser::TextParser;
 
@@ -215,7 +215,7 @@ pub struct Script(pub(crate) Tag);
 impl Script {
     #[inline]
     pub(crate) const fn from_bytes(bytes: &[u8; 4]) -> Self {
-        Script(Tag::from_bytes(bytes))
+        Script(Tag::new(bytes))
     }
 
     /// Converts an ISO 15924 script tag to a corresponding `Script`.
@@ -225,9 +225,9 @@ impl Script {
         }
 
         // Be lenient, adjust case (one capital letter followed by three small letters).
-        let tag = Tag((tag.as_u32() & 0xDFDFDFDF) | 0x00202020);
+        let tag = Tag::from_u32((tag.as_u32() & 0xDFDFDFDF) | 0x00202020);
 
-        match &tag.to_bytes() {
+        match &tag.to_be_bytes() {
             // These graduated from the 'Q' private-area codes, but
             // the old code is still aliased by Unicode, and the Qaai
             // one in use by ICU.
@@ -628,7 +628,7 @@ mod tests_features {
             fn $name() {
                 assert_eq!(
                     Feature::from_str($text).unwrap(),
-                    Feature::new(Tag::from_bytes($tag), $value, $range)
+                    Feature::new(Tag::new($tag), $value, $range)
                 );
             }
         };
@@ -703,6 +703,9 @@ impl core::str::FromStr for Variation {
 }
 
 pub trait TagExt {
+    fn from_bytes_lossy(bytes: &[u8]) -> Self;
+    fn as_u32(self) -> u32;
+    fn is_null(self) -> bool;
     fn default_script() -> Self;
     fn default_language() -> Self;
     #[cfg(test)]
@@ -711,22 +714,38 @@ pub trait TagExt {
 }
 
 impl TagExt for Tag {
+    fn from_bytes_lossy(bytes: &[u8]) -> Self {
+        let mut array = [b' '; 4];
+        for (src, dest) in bytes.iter().zip(&mut array) {
+            *dest = *src;
+        }
+        Tag::new(&array)
+    }
+
+    fn as_u32(self) -> u32 {
+        u32::from_be_bytes(self.to_be_bytes())
+    }
+
+    fn is_null(self) -> bool {
+        self.to_be_bytes() == [0, 0, 0, 0]
+    }
+
     #[inline]
     fn default_script() -> Self {
-        Tag::from_bytes(b"DFLT")
+        Tag::new(b"DFLT")
     }
 
     #[inline]
     fn default_language() -> Self {
-        Tag::from_bytes(b"dflt")
+        Tag::new(b"dflt")
     }
 
     /// Converts tag to lowercase.
     #[cfg(test)]
     #[inline]
     fn to_lowercase(&self) -> Self {
-        let b = self.to_bytes();
-        Tag::from_bytes(&[
+        let b = self.to_be_bytes();
+        Tag::new(&[
             b[0].to_ascii_lowercase(),
             b[1].to_ascii_lowercase(),
             b[2].to_ascii_lowercase(),
@@ -737,8 +756,8 @@ impl TagExt for Tag {
     /// Converts tag to uppercase.
     #[inline]
     fn to_uppercase(&self) -> Self {
-        let b = self.to_bytes();
-        Tag::from_bytes(&[
+        let b = self.to_be_bytes();
+        Tag::new(&[
             b[0].to_ascii_uppercase(),
             b[1].to_ascii_uppercase(),
             b[2].to_ascii_uppercase(),

src/hb/face.rs

@@ -8,6 +8,7 @@ use ttf_parser::{GlyphId, RgbaColor};
 
 use super::buffer::GlyphPropsFlags;
 use super::fonta;
+use super::common::TagExt;
 use super::ot_layout::TableIndex;
 use crate::Variation;
 
@@ -81,7 +82,7 @@ impl<'a> hb_font_t<'a> {
     /// Sets font variations.
     pub fn set_variations(&mut self, variations: &[Variation]) {
         for variation in variations {
-            self.ttfp_face.set_variation(variation.tag, variation.value);
+            self.ttfp_face.set_variation(ttf_parser::Tag(variation.tag.as_u32()), variation.value);
         }
         self.font.set_coords(self.ttfp_face.variation_coordinates());
     }

src/hb/fonta/ot/mod.rs

@@ -168,10 +168,6 @@ pub enum LayoutTable<'a> {
     Gpos(Gpos<'a>),
 }
 
-fn conv_tag(tag: hb_tag_t) -> skrifa::raw::types::Tag {
-    skrifa::raw::types::Tag::from_u32(tag.0)
-}
-
 impl<'a> LayoutTable<'a> {
     fn script_list(&self) -> Option<ScriptList<'a>> {
         match self {
@@ -199,7 +195,6 @@ impl<'a> LayoutTable<'a> {
 
     fn script_index(&self, tag: hb_tag_t) -> Option<u16> {
         let list = self.script_list()?;
-        let tag = conv_tag(tag);
         list.script_records()
             .binary_search_by_key(&tag, |rec| rec.script_tag())
             .map(|index| index as u16)
@@ -214,7 +209,6 @@ impl<'a> LayoutTable<'a> {
 
     fn langsys_index(&self, script_index: u16, tag: hb_tag_t) -> Option<u16> {
         let script = self.script(script_index)?;
-        let tag = conv_tag(tag);
         script
             .lang_sys_records()
             .binary_search_by_key(&tag, |rec| rec.lang_sys_tag())
@@ -241,7 +235,7 @@ impl<'a> LayoutTable<'a> {
     fn feature_tag(&self, index: u16) -> Option<hb_tag_t> {
         let list = self.feature_list()?;
         let record = list.feature_records().get(index as usize)?;
-        Some(hb_tag_t(u32::from_be_bytes(record.feature_tag().to_raw())))
+        Some(record.feature_tag())
     }
 
     pub(crate) fn feature_variation_index(&self, coords: &[F2Dot14]) -> Option<u32> {
@@ -310,7 +304,6 @@ impl<'a> LayoutTable<'a> {
 
     pub(crate) fn feature_index(&self, tag: hb_tag_t) -> Option<u16> {
         let list = self.feature_list()?;
-        let tag = conv_tag(tag);
         for (index, feature) in list.feature_records().iter().enumerate() {
             if feature.feature_tag() == tag {
                 return Some(index as u16);
@@ -351,7 +344,7 @@ impl crate::hb::ot_layout::LayoutTableExt for LayoutTable<'_> {
             hb_tag_t::default_language(),
             // try with 'latn'; some old fonts put their features there even though
             // they're really trying to support Thai, for example :(
-            hb_tag_t::from_bytes(b"latn"),
+            hb_tag_t::new(b"latn"),
         ] {
             if let Some(index) = self.script_index(tag) {
                 return Some((false, index, tag));

src/hb/mod.rs

@@ -58,7 +58,7 @@ mod text_parser;
 mod unicode;
 mod unicode_norm;
 
-use ttf_parser::Tag as hb_tag_t;
+use skrifa::raw::types::Tag as hb_tag_t;
 
 use self::buffer::hb_glyph_info_t;
 use self::face::hb_font_t;

src/hb/ot_layout.rs

@@ -125,103 +125,6 @@ pub trait LayoutTableExt {
     ) -> Option<FeatureIndex>;
 }
 
-impl LayoutTableExt for ttf_parser::opentype_layout::LayoutTable<'_> {
-    // hb_ot_layout_table_select_script
-    /// Returns true + index and tag of the first found script tag in the given GSUB or GPOS table
-    /// or false + index and tag if falling back to a default script.
-    fn select_script(&self, script_tags: &[hb_tag_t]) -> Option<(bool, ScriptIndex, hb_tag_t)> {
-        for &tag in script_tags {
-            if let Some(index) = self.scripts.index(tag) {
-                return Some((true, index, tag));
-            }
-        }
-
-        for &tag in &[
-            // try finding 'DFLT'
-            hb_tag_t::default_script(),
-            // try with 'dflt'; MS site has had typos and many fonts use it now :(
-            hb_tag_t::default_language(),
-            // try with 'latn'; some old fonts put their features there even though
-            // they're really trying to support Thai, for example :(
-            hb_tag_t::from_bytes(b"latn"),
-        ] {
-            if let Some(index) = self.scripts.index(tag) {
-                return Some((false, index, tag));
-            }
-        }
-
-        None
-    }
-
-    // hb_ot_layout_script_select_language
-    /// Returns the index of the first found language tag in the given GSUB or GPOS table,
-    /// underneath the specified script index.
-    fn select_script_language(
-        &self,
-        script_index: ScriptIndex,
-        lang_tags: &[hb_tag_t],
-    ) -> Option<LanguageIndex> {
-        let script = self.scripts.get(script_index)?;
-
-        for &tag in lang_tags {
-            if let Some(index) = script.languages.index(tag) {
-                return Some(index);
-            }
-        }
-
-        // try finding 'dflt'
-        if let Some(index) = script.languages.index(hb_tag_t::default_language()) {
-            return Some(index);
-        }
-
-        None
-    }
-
-    // hb_ot_layout_language_get_required_feature
-    /// Returns the index and tag of a required feature in the given GSUB or GPOS table,
-    /// underneath the specified script and language.
-    fn get_required_language_feature(
-        &self,
-        script_index: ScriptIndex,
-        lang_index: Option<LanguageIndex>,
-    ) -> Option<(FeatureIndex, hb_tag_t)> {
-        let script = self.scripts.get(script_index)?;
-        let sys = match lang_index {
-            Some(index) => script.languages.get(index)?,
-            None => script.default_language?,
-        };
-        let idx = sys.required_feature?;
-        let tag = self.features.get(idx)?.tag;
-        Some((idx, tag))
-    }
-
-    // hb_ot_layout_language_find_feature
-    /// Returns the index of a given feature tag in the given GSUB or GPOS table,
-    /// underneath the specified script and language.
-    fn find_language_feature(
-        &self,
-        script_index: ScriptIndex,
-        lang_index: Option<LanguageIndex>,
-        feature_tag: hb_tag_t,
-    ) -> Option<FeatureIndex> {
-        let script = self.scripts.get(script_index)?;
-        let sys = match lang_index {
-            Some(index) => script.languages.get(index)?,
-            None => script.default_language?,
-        };
-
-        for i in 0..sys.feature_indices.len() {
-            if let Some(index) = sys.feature_indices.get(i) {
-                if self.features.get(index).map(|v| v.tag) == Some(feature_tag) {
-                    return Some(index);
-                }
-            }
-        }
-
-        None
-    }
-}
-
 /// Called before substitution lookups are performed, to ensure that glyph
 /// class and other properties are set on the glyphs in the buffer.
 pub fn hb_ot_layout_substitute_start(face: &hb_font_t, buffer: &mut hb_buffer_t) {

src/hb/ot_map.rs

@@ -3,13 +3,16 @@ use core::cmp::Ordering;
 use core::ops::Range;
 use ttf_parser::FromData;
 
-use ttf_parser::opentype_layout::{
-    FeatureIndex, LanguageIndex, LookupIndex, ScriptIndex, VariationIndex,
-};
+pub type FeatureIndex = u16;
+pub type LanguageIndex = u16;
+pub type LookupIndex = u16;
+pub type ScriptIndex = u16;
+pub type VariationIndex = u32;
 
 use super::buffer::{glyph_flag, hb_buffer_t};
 use super::ot_layout::{LayoutTableExt, TableIndex};
 use super::ot_shape_plan::hb_ot_shape_plan_t;
+use super::common::TagExt;
 use super::{hb_font_t, hb_mask_t, hb_tag_t, tag, Language, Script};
 
 pub struct hb_ot_map_t {