Fix frac feature for better recognizing fraction patterns (#2214).

changes/29.0.0.md

@@ -41,3 +41,4 @@
 * Unify diagonal box drawings' angles (#2197).
 * Fix Large Type Piece `U+1CE3B` (#2206).
 * Added a `MOSC` feature that turns certain geometric shapes into mosaics (#2212).
+* Fix `frac` feature for better recognizing fraction patterns (#2214).

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

@@ -111,21 +111,6 @@ glyph-block Autobuild-Transformed : begin
 		createSuperscripts 'sup' null : list
 			list 0x00AA 'aSbRsbUnderlineBelow'
 			list 0x00BA 'oSbRsbUnderlineBelow'
-			list 0x2070 'zero.lnum'
-			list 0x00B9 'one.lnum'
-			list 0x00B2 'two.lnum'
-			list 0x00B3 'three.lnum'
-			list 0x2074 'four.lnum'
-			list 0x2075 'five.lnum'
-			list 0x2076 'six.lnum'
-			list 0x2077 'seven.lnum'
-			list 0x2078 'eight.lnum'
-			list 0x2079 'nine.lnum'
-			list 0x207A 'plus'
-			list 0x207B 'minus'
-			list 0x207C 'equal'
-			list 0x207D 'parenLeft'
-			list 0x207E 'parenRight'
 			list 0x02B0 'h'
 			list 0x02B1 'hHookTop'
 			list 0x02B2 'j'
@@ -143,6 +128,11 @@ glyph-block Autobuild-Transformed : begin
 			list 0x02E3 'x'
 			list 0x02E4 'revGlottalStop'
 			list 0x2071 'i'
+			list 0x207A 'plus'
+			list 0x207B 'minus'
+			list 0x207C 'equal'
+			list 0x207D 'parenLeft'
+			list 0x207E 'parenRight'
 			list 0x207F 'n'
 			list 0x1D43 'a'
 			list 0x1D44 'turna'
@@ -214,6 +204,7 @@ glyph-block Autobuild-Transformed : begin
 			list 0x1DBE 'ezh'
 			list 0x1DBF 'grek/theta'
 			list 0x1D2C 'A'
+			list 0x1D2D 'AE'
 			list 0x1D2E 'B'
 			list 0x1D2F 'BBar'
 			list 0x1D30 'D'
@@ -352,24 +343,17 @@ glyph-block Autobuild-Transformed : begin
 			list null 'seven.onum'
 			list null 'eight.onum'
 			list null 'nine.onum'
-			list null 'zero.lnum'
+			list 0x2070 'zero.lnum'
-			list null 'one.lnum'
+			list 0x00B9 'one.lnum'
-			list null 'two.lnum'
+			list 0x00B2 'two.lnum'
-			list null 'three.lnum'
+			list 0x00B3 'three.lnum'
-			list null 'four.lnum'
+			list 0x2074 'four.lnum'
-			list null 'five.lnum'
+			list 0x2075 'five.lnum'
-			list null 'six.lnum'
+			list 0x2076 'six.lnum'
-			list null 'seven.lnum'
+			list 0x2077 'seven.lnum'
-			list null 'eight.lnum'
+			list 0x2078 'eight.lnum'
-			list null 'nine.lnum'
+			list 0x2079 'nine.lnum'
-
+			list null 'period'
-		do "superscript AE"
-			define { tnmAHalf jobsAHalf } : createSuperscripts 'sup' null { { null 'AE/AHalf' } }
-			define { tnmEHalf jobsEHalf } : createSuperscripts 'sup' null { { null 'AE/EHalf' } }
-			create-glyph 'sup{AE}' 0x1D2D : glyph-proc
-				include [refer-glyph tnmAHalf.('AE/AHalf')] AS_BASE ALSO_METRICS
-				include [refer-glyph tnmEHalf.('AE/EHalf')]
-				CvDecompose.set currentGlyph { tnmAHalf.('AE/AHalf') tnmEHalf.('AE/EHalf') }
 
 	: where : [createSuperscripts prefix gr _records] : begin
 		local {records relSets targetNameMap} : extendRelatedGlyphs prefix _records
@@ -394,16 +378,6 @@ glyph-block Autobuild-Transformed : begin
 
 	do
 		createSubscripts 'sub' null : list
-			list 0x2080 'zero.lnum'
-			list 0x2081 'one.lnum'
-			list 0x2082 'two.lnum'
-			list 0x2083 'three.lnum'
-			list 0x2084 'four.lnum'
-			list 0x2085 'five.lnum'
-			list 0x2086 'six.lnum'
-			list 0x2087 'seven.lnum'
-			list 0x2088 'eight.lnum'
-			list 0x2089 'nine.lnum'
 			list 0x208A 'plus'
 			list 0x208B 'minus'
 			list 0x208C 'equal'
@@ -475,16 +449,17 @@ glyph-block Autobuild-Transformed : begin
 			list null 'seven.onum'
 			list null 'eight.onum'
 			list null 'nine.onum'
-			list null 'zero.lnum'
+			list 0x2080 'zero.lnum'
-			list null 'one.lnum'
+			list 0x2081 'one.lnum'
-			list null 'two.lnum'
+			list 0x2082 'two.lnum'
-			list null 'three.lnum'
+			list 0x2083 'three.lnum'
-			list null 'four.lnum'
+			list 0x2084 'four.lnum'
-			list null 'five.lnum'
+			list 0x2085 'five.lnum'
-			list null 'six.lnum'
+			list 0x2086 'six.lnum'
-			list null 'seven.lnum'
+			list 0x2087 'seven.lnum'
-			list null 'eight.lnum'
+			list 0x2088 'eight.lnum'
-			list null 'nine.lnum'
+			list 0x2089 'nine.lnum'
+			list null 'period'
 
 	: where : [createSubscripts prefix gr _records] : begin
 		local {records relSets targetNameMap} : extendRelatedGlyphs prefix _records

packages/font-otl/src/gsub-frac.ptl

@@ -9,10 +9,6 @@ export : define [buildFrac gsub glyphStore] : begin
 	define frac : gsub.addCommonFeature : gsub.createFeature 'frac'
 	define { chain-rule reverse-rule } : gsub.ChainRuleBuilder
 
-	define subSolidus : gsub.createLookup : object
-		.type 'gsub_single'
-		.substitutions : object ['solidus' 'fractionBar'] ['slash' 'fractionBar']
-
 	define digitSet { }
 	define numSet   { }
 	define denSet   { }
@@ -25,6 +21,11 @@ export : define [buildFrac gsub glyphStore] : begin
 			numSet.push   numForm
 			denSet.push   denForm
 
+	define subSolidus : gsub.createLookup : object
+		.type 'gsub_chaining'
+		.rules : list
+			chain-rule digitSet ({'solidus' 'slash'} ~> {'fractionBar' 'fractionBar'}) digitSet
+
 	define subDen : gsub.createLookup : object
 		.type 'gsub_chaining'
 		.rules : list