Support slope-dependent digit form control (#724).

README.md

@@ -324,9 +324,6 @@ Configuration of build plans are organized under `[buildPlans.<plan name>]` sect
   - Otherwise the font will be sans-serif.
 * `no-cv-ss`: Optional, Boolean, disables `cv##` and `ss##` OpenType features.
 * `no-ligation`: Optional, Boolean, disables ligations.
-* `digit-form`: Optional, String, configures the default form of digits (figures).
-  - When set to `old-style`, old-style digit figures will be used.
-  - When absent or set to `lining`, lining digit figures will be used.
 
 Build plan could have 5 optional subsections: `ligations`, `variants`, `weights`, `widths` and `slopes`.
 
@@ -424,8 +421,15 @@ Subsection `variants` is used to configure character variants in the font. Prope
 <!-- BEGIN Section-Cherry-Picking-Styles -->
 <!-- THIS SECTION IS AUTOMATICALLY GENERATED. DO NOT EDIT. -->
 
-* `design`, `upright`, `italic`, and `oblique`: Optional, Dictionary, defines styles for individual characters. The choices are organized in key-value pairs, assigning a variant to a character group. Alternatively, you could assign numbers to `cv##` tags, like what you did when using OpenType in CSS. Assignments under `design` will be applied to all the slopes, and `upright`, `italic`, and `oblique` will apply to corresponded slopes. The valid combinations include:
+* `design`, `upright`, `italic`, and `oblique`: Optional, Dictionary, defines styles for individual characters. The choices are organized in key-value pairs, assigning a variant to a character group. Alternatively, you could assign numbers to `cv##` tags, like what you did when using OpenType in CSS. Assignments under `design` will be applied to all the slopes, and `upright`, `italic`, and `oblique` will apply to corresponded slopes. 
 
+  In addition, style selector for default digit form also uses these dictionaries.
+  
+  The valid combinations include:
+
+  - Default digit form:
+    - `digit-form = 'lining'`: Lining (default).
+    - `digit-form = 'old-style'`: Old-style.
   - Styles for `A`, `Λ`, `Δ`:
     + `turn-v = 'straight'`, `cv01 = 1`: Standard, straight `A`, `Λ`, `Δ` (default).
     + `turn-v = 'curly'`, `cv01 = 2`: Slightly curly `A`, `Λ`, `Δ`, like Iosevka 2.x.

changes/4.0.0-beta.1.md

@@ -4,3 +4,4 @@
  * Fix incorrect serifs of Greek Small Rho (#718).
  * Add derived bold / italic / sans-serif / typewriter letters in Mathematical Alphanumeric Symbols block.
  * Add shorter-serif variant for capital I (#709).
+ * Support slope-dependent digit form control (#724).

font-src/glyphs/number/index.ptl

@@ -22,8 +22,8 @@ glyph-block Digits-Shared : begin
 		p : MarkSet.OfZone {.top OnumHeight .bot (OnumHeight - CAP)}
 
 	glyph-block-export CodeLnum CodeOnum
-	define [CodeLnum u] : if para.defaultToOldStyleFigures null u
-	define [CodeOnum u] : if para.defaultToOldStyleFigures u null
+	define [CodeLnum u] : if (para.variantSelector.__defaultDigitForm == 'oldStyle') null u
+	define [CodeOnum u] : if (para.variantSelector.__defaultDigitForm == 'oldStyle') u null
 
 glyph-block Digits-Zero : begin
 	glyph-block-import CommonShapes

font-src/support/parameters.js

@@ -8,7 +8,6 @@ function initPara(data, argv) {
 	apply(para, data, ["iosevka"]);
 	if (argv.shape.serifs) apply(para, data, ["serifs-" + argv.shape.serifs]);
 	if (argv.shape.spacing) apply(para, data, ["spacing-" + argv.shape.spacing]);
-	if (argv.shape.digitForm) apply(para, data, ["digit-form-" + argv.shape.digitForm]);
 	apply(para, data, ["shapeWeight"], { shapeWeight: argv.shape.weight });
 	apply(para, data, ["shapeWidth"], { shapeWidth: argv.shape.width });
 	apply(para, data, [`s-${argv.shape.slope}`]);

params/parameters.toml

@@ -64,9 +64,6 @@ excludedCharRanges = []
 #  - 2+ : Full     (3.x)
 slab = 0
 
-# Enable old-style digits by default?
-defaultToOldStyleFigures = false
-
 [verbose]
 verbose = true
 
@@ -120,9 +117,3 @@ diversityF = 0.75
 diversityI = 0.75
 diversityII = 0.5
 
-###### Old-style figures
-[digit-form-old-style]
-defaultToOldStyleFigures = true
-
-[digit-form-lining]
-defaultToOldStyleFigures = false

params/variants.toml

@@ -1644,6 +1644,13 @@ selector.r = "narrow"
 selector."turnrrtail" = "narrow"
 selector."rflap" = "narrow"
 
+# This is a special variant selector that controls digit form
+[prime.digit-form.variants.lining]
+selector.__defaultDigitForm = "lining"
+
+[prime.digit-form.variants.old-style]
+selector.__defaultDigitForm = "oldStyle"
+
 ###################################################################################################
 
 [default.design]
@@ -1703,6 +1710,8 @@ ascii-grave = 'straight'
 h = 'straight'
 m = 'normal'
 n = 'straight'
+# Digit form
+digit-form = 'lining'
 
 [default.upright-oblique]
 a = 'doublestorey'

private-build-plans.sample.toml

@@ -2,7 +2,6 @@
 family = "Iosevka Custom"        # Font menu family name
 spacing = "normal"               # Optional; Values: `normal`, `term`, `fontconfig-mono`, or `fixed`
 serifs = "sans"                  # Optional; Values: `sans` or `slab`
-digit-form = "lining"            # Optional; Values `lining` or `old-style`
 
 ###################################################################################################
 # Configure variants

utility/amend-readme/fragments/description-cheery-picking-styles.md

@@ -1 +1,5 @@
-* `design`, `upright`, `italic`, and `oblique`: Optional, Dictionary, defines styles for individual characters. The choices are organized in key-value pairs, assigning a variant to a character group. Alternatively, you could assign numbers to `cv##` tags, like what you did when using OpenType in CSS. Assignments under `design` will be applied to all the slopes, and `upright`, `italic`, and `oblique` will apply to corresponded slopes. The valid combinations include:
+* `design`, `upright`, `italic`, and `oblique`: Optional, Dictionary, defines styles for individual characters. The choices are organized in key-value pairs, assigning a variant to a character group. Alternatively, you could assign numbers to `cv##` tags, like what you did when using OpenType in CSS. Assignments under `design` will be applied to all the slopes, and `upright`, `italic`, and `oblique` will apply to corresponded slopes. 
+
+  In addition, style selector for default digit form also uses these dictionaries.
+  
+  The valid combinations include:

utility/amend-readme/fragments/special-variant-digit-form.md

@@ -0,0 +1,3 @@
+  - Default digit form:
+    - `digit-form = 'lining'`: Lining (default).
+    - `digit-form = 'old-style'`: Old-style.

utility/amend-readme/index.js

@@ -71,6 +71,9 @@ async function processCv() {
 	const headerPath = path.resolve(__dirname, "fragments/description-cheery-picking-styles.md");
 	md.log(await fs.readFile(headerPath, "utf-8"));
 
+	const cvDigitFormPath = path.resolve(__dirname, "fragments/special-variant-digit-form.md");
+	md.log(await fs.readFile(cvDigitFormPath, "utf-8"));
+
 	for (const gr of variantsData.primes) {
 		const sampleText = gr.descSampleText
 			.map(c => (c === "`" ? "`` ` ``" : `\`${c}\``))