metrics: Update apple system font metrics (#193)

.changeset/curvy-forks-brush.md

@@ -0,0 +1,10 @@
+---
+'@capsizecss/metrics': patch
+---
+
+metrics: Update apple system font metrics
+
+Previously the metrics provided for `-apple-system` and `BlinkMacSystemFont` were extracted from the `SF Pro` font, with a custom override to correct the `descent` metric.
+
+Through work to support metrics for different font weights and styles, it was identified that MacOS uses the `SFNS` font.
+Extracting the metrics from this font means no more custom overrides, and will now enable using this font as a fallback via postscript name soon too.

packages/metrics/scripts/source-data/systemFontsData.ts

@@ -8,23 +8,20 @@ if (!fontDirectory) {
   );
 }
 
-const sfProBase: Omit<FontSourceList[number], 'family'> = {
+const sfNSBase: Omit<FontSourceList[number], 'family'> = {
   category: 'sans-serif',
   files: {
-    regular: `${fontDirectory}/SF Pro.ttf`,
-  },
-  overrides: {
-    descent: -420,
+    regular: `${fontDirectory}/SFNS.ttf`,
   },
 } as const;
 
 const systemFonts: FontSourceList = [
   {
-    ...sfProBase,
+    ...sfNSBase,
     family: '-apple-system',
   },
   {
-    ...sfProBase,
+    ...sfNSBase,
     family: 'BlinkMacSystemFont',
   },
   {

packages/metrics/scripts/systemFonts.json

@@ -2,8 +2,8 @@
   {
     "familyName": "-apple-system",
     "capHeight": 1443,
-    "ascent": 1950,
-    "descent": -420,
+    "ascent": 1980,
+    "descent": -432,
     "lineGap": 0,
     "unitsPerEm": 2048,
     "xHeight": 1040,
@@ -40,8 +40,8 @@
   {
     "familyName": "BlinkMacSystemFont",
     "capHeight": 1443,
-    "ascent": 1950,
-    "descent": -420,
+    "ascent": 1980,
+    "descent": -432,
     "lineGap": 0,
     "unitsPerEm": 2048,
     "xHeight": 1040,