[glyphs] Handle additional custom params

Specifically openTypeHeadLowestRecPPEM, and the various hhea & vhea
caret properties.

(vhea isn't handled yet, but we can at least parse it now in preparation)

glyphs-reader/src/font.rs

@@ -95,6 +95,13 @@ pub struct CustomParameters {
     pub codepage_range_bits: Option<BTreeSet<u32>>,
     pub panose: Option<Vec<i64>>,
 
+    pub lowest_rec_ppem: Option<i64>,
+    pub hhea_caret_slope_run: Option<i64>,
+    pub hhea_caret_slope_rise: Option<i64>,
+    pub hhea_caret_offset: Option<i64>,
+    pub vhea_caret_slope_run: Option<i64>,
+    pub vhea_caret_slope_rise: Option<i64>,
+    pub vhea_caret_offset: Option<i64>,
     // these fields are parsed via the config, but are stored
     // in the top-level `Font` struct
     pub virtual_masters: Option<Vec<BTreeMap<String, OrderedFloat<f64>>>>,
@@ -520,7 +527,15 @@ impl RawCustomParameters {
         {
             macro_rules! add_and_report_issues {
                 ($field:ident, $converter:path) => {{
-                    let value = $converter(value);
+                    add_and_report_issues!($field, $converter(value))
+                }};
+
+                ($field:ident, $converter:path, into) => {{
+                    add_and_report_issues!($field, $converter(value).map(Into::into))
+                }};
+
+                ($field:ident, $value_expr:expr) => {{
+                    let value = $value_expr;
 
                     if value.is_none() {
                         log::warn!("failed to parse param for '{}'", stringify!($field));
@@ -570,14 +585,48 @@ impl RawCustomParameters {
                 "codePageRanges" => {
                     add_and_report_issues!(codepage_range_bits, Plist::as_codepage_bits)
                 }
+                // these values are not listed in the glyphs.app UI, but exist
+                // in some fonts. Maybe only fonts converted to glyphs format
+                // from something else?
+                "openTypeHeadLowestRecPPEM" => {
+                    add_and_report_issues!(lowest_rec_ppem, Plist::as_i64)
+                }
+                "openTypeHheaCaretSlopeRun" => {
+                    add_and_report_issues!(hhea_caret_slope_run, Plist::as_i64)
+                }
+                "openTypeHheaCaretSlopeRise" => {
+                    add_and_report_issues!(hhea_caret_slope_rise, Plist::as_i64)
+                }
+                "openTypeHheaCaretOffset" => {
+                    add_and_report_issues!(hhea_caret_offset, Plist::as_i64)
+                }
+                "openTypeVheaCaretSlopeRun" => {
+                    add_and_report_issues!(vhea_caret_slope_run, Plist::as_i64)
+                }
+                "openTypeVheaCaretSlopeRise" => {
+                    add_and_report_issues!(vhea_caret_slope_rise, Plist::as_i64)
+                }
+                "openTypeVheaCaretOffset" => {
+                    add_and_report_issues!(vhea_caret_offset, Plist::as_i64)
+                }
+                // these might need to be handled? they're in the same list as
+                // the items above:
+                // https://github.com/googlefonts/glyphsLib/blob/74c63244fdb/Lib/glyphsLib/builder/custom_params.py#L429
+                "openTypeNameUniqueID"
+                | "openTypeNameVersion"
+                | "openTypeOS2FamilyClass"
+                | "openTypeHeadFlags" => {
+                    log::warn!("unhandled custom param '{name}'")
+                }
+
                 "Virtual Master" => match value.as_virtual_master() {
                     Some(val) => virtual_masters.push(val),
                     None => log::warn!("failed to parse virtual master '{value:?}'"),
                 },
                 "panose" => panose = value.as_vec_of_ints(),
                 "openTypeOS2Panose" => panose_old = value.as_vec_of_ints(),
                 "glyphOrder" => add_and_report_issues!(glyph_order, Plist::as_vec_of_string),
-                _ => log::warn!("unhandled custom parameter '{name}'"),
+                _ => log::warn!("unknown custom parameter '{name}'"),
             }
         }
         params.panose = panose.or(panose_old);
@@ -2266,6 +2315,7 @@ impl TryFrom<RawFont> for Font {
 
         let mut custom_parameters = from.custom_parameters.cook()?;
         let glyph_order = make_glyph_order(&from.glyphs, custom_parameters.glyph_order.take());
+
         let axes = from.axes.clone();
         let instances: Vec<_> = from
             .instances

glyphs2fontir/src/source.rs

@@ -429,6 +429,9 @@ impl Work<Context, WorkId, Error> for StaticMetadataWork {
 
         static_metadata.misc.version_major = font.version_major;
         static_metadata.misc.version_minor = font.version_minor;
+        if let Some(lowest_rec_ppm) = font.custom_parameters.lowest_rec_ppem {
+            static_metadata.misc.lowest_rec_ppm = lowest_rec_ppm as _;
+        }
 
         static_metadata.misc.created = font
             .date
@@ -607,6 +610,9 @@ impl Work<Context, WorkId, Error> for GlobalMetricWork {
             set_metric!(HheaAscender, hhea_ascender);
             set_metric!(HheaDescender, hhea_descender);
             set_metric!(HheaLineGap, hhea_line_gap);
+            set_metric!(CaretSlopeRun, hhea_caret_slope_run);
+            set_metric!(CaretSlopeRise, hhea_caret_slope_rise);
+            set_metric!(CaretOffset, hhea_caret_offset);
             // 50.0 is the Glyphs default <https://github.com/googlefonts/glyphsLib/blob/9d5828d874110c42dfc5f542db8eb84f88641eb5/Lib/glyphsLib/builder/custom_params.py#L1136-L1156>
             set_metric!(UnderlineThickness, underline_thickness, 50.0);
             // -100.0 is the Glyphs default <https://github.com/googlefonts/glyphsLib/blob/9d5828d874110c42dfc5f542db8eb84f88641eb5/Lib/glyphsLib/builder/custom_params.py#L1136-L1156>
@@ -1846,4 +1852,19 @@ mod tests {
             context.static_metadata.get().misc.panose
         );
     }
+
+    #[test]
+    fn capture_unsual_params() {
+        // both parameters; value under short name should be preferred
+        let (_, context) = build_static_metadata(glyphs3_dir().join("UnusualCustomParams.glyphs"));
+        let meta = context.static_metadata.get();
+        assert_eq!(meta.misc.lowest_rec_ppm, 7);
+
+        // some of these end up as metrics:
+        let (_, context) = build_global_metrics(glyphs3_dir().join("UnusualCustomParams.glyphs"));
+        let metrics = context.global_metrics.get();
+        assert_eq!(unique_value(&metrics, GlobalMetric::CaretOffset), 2.);
+        assert_eq!(unique_value(&metrics, GlobalMetric::CaretSlopeRise), 1.);
+        assert_eq!(unique_value(&metrics, GlobalMetric::CaretSlopeRun), 5.);
+    }
 }