Add metric override for archDepth and smallArchDepth (#1313).

changes/15.0.0.md

@@ -1,3 +1,5 @@
+ * \[**Breaking**\] Metric override name change: `xheight` → `xHeight`.
  * Add variant selector for dot and comma diacritics (#1309).
  * Fix enclosed glyphs' placement when having glyphs with different Y-shifting (#1310).
+ * Add metric override for `archDepth` and `smallArchDepth` (#1313).
  

doc/custom-build.md

@@ -450,7 +450,7 @@ Subsection `metric-override` provides ability to override certain metric values,
 | Property | Unit | Default Value | Meaning |
 |----------|------|---------|----------|
 | `cap` | emu | 735 | Height of `H`. |
-| `xheight` | emu | 520 | Height of `x`. |
+| `xHeight` | emu | 520 | Height of `x`. |
 | `sb` | emu | (*varies, 60 for Regular*) | Width of common side-bearings. |
 | `accentWidth` | emu | 200 | Width of accent marks. |
 | `accentClearance` | emu | 72 | Vertical clearance of accent marks to the base. |
@@ -470,6 +470,8 @@ Subsection `metric-override` provides ability to override certain metric values,
 | `essRatioUpper` | (*ratio*) | (*varies, 1.12 for Regular*) | Ratio of the thickness of the neck of `S`, to the normal stroke width. |
 | `essRatioLower` | (*ratio*) | (*varies, 1.12 for Regular*) | Ratio of the thickness of the neck of `s`, to the normal stroke width. |
 | `essRatioQuestion` | (*ratio*) | (*varies, 1.12 for Regular*) | Ratio of the thickness of the neck of `?`, to the normal stroke width. |
+| `archDepth` | emu | (*varies, 195 for Regular*) | Depth of the curve segment of arches / O rings in capital letters. |
+| `smallArchDepth` | emu | (*varies, 200 for Regular*) | Depth of the curve segment of arches / O rings in small letters. |
 
 The values of each item could be either a number, or a string representing an expression so that it could be different for different instance fonts, or depending on default values. The syntax of valid expressions are:
 

font-src/glyphs/auto-build/transformed.ptl

@@ -129,7 +129,7 @@ glyph-block Autobuild-Transformed : begin
 		local forkedParams : Object.create para
 		set forkedParams.cap0 para.cap
 		set forkedParams.cap XH
-		set forkedParams.xheight (XH * XH / CAP)
+		set forkedParams.xHeight (XH * XH / CAP)
 		set forkedParams.diversityM 1
 		set forkedParams.diversityF 1
 		set forkedParams.diversityI 1

font-src/meta/aesthetics.ptl

@@ -12,7 +12,7 @@ export : define [calculateMetrics para] : begin
 	define Width : Math.round para.width
 	define SB para.sb
 	define CAP para.cap
-	define XH para.xheight
+	define XH para.xHeight
 	define Descender : fallback para.descender (XH - CAP)
 	define Contrast : fallback para.contrast 1
 	# Key metrics for symbols

font-src/support/metric-override.js

@@ -25,7 +25,7 @@ function applyMetricOverride(para, mo, argv) {
 
 const validMetricOverrideFields = new Set([
 	"cap",
-	"xheight",
+	"xHeight",
 	"sb",
 	"accentWidth",
 	"accentClearance",
@@ -46,7 +46,9 @@ const validMetricOverrideFields = new Set([
 	"essRatioUpper",
 	"essRatioLower",
 	"essRatioQuestion",
-	"essRatio"
+	"essRatio",
+	"archDepth",
+	"smallArchDepth"
 ]);
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////

params/parameters.toml

@@ -12,7 +12,7 @@ naming.description = 'Spatial efficient monospace font family for programming. B
 leading = 1250     # Default line height times 1000.
 descenderPad = 0   # Additional line height, added to descender.
 cap = 735          # Cap height (as well as ascender).
-xheight = 520      # X-height.
+xHeight = 520      # X-height.
 #descender = -205  # Depth of descender. Currently unused.
 winMetricAscenderPad  = 0 # Padding of Win ascnder metrics to avoid clipping. See #343
 winMetricDescenderPad = 0 # Padding of Win descender metrics to avoid clipping. See #343