* Fix serifs of certain letters (#1458):

- LATIN CAPITAL LETTER GAMMA (`U+0194`);
  - LATIN CAPITAL LETTER OU (`U+0222`);
  - LATIN SMALL LETTER OU (`U+0223`);
  - LATIN SMALL LETTER ALPHA (`U+0251`);
  - LATIN SMALL LETTER GAMMA (`U+0263`);
  - LATIN SMALL LETTER RAMS HORN (`U+0264`);
  - LATIN SMALL LETTER TURNED OPEN E (`U+1D08`);
  - LATIN LETTER SMALL CAPITAL OU (`U+1D15`);
  - LATIN LETTER AIN (`U+1D25`);

changes/16.6.1.md

@@ -1,2 +1,12 @@
  * Fix metrics of ASCII single quotes under Aile (#1454).
  * Fix overshoot of oval-shaped `0`, and open `6`/`9` (#1455).
+ * Fix serifs of certain letters (#1458):
+  - LATIN CAPITAL LETTER GAMMA (`U+0194`);
+  - LATIN CAPITAL LETTER OU (`U+0222`);
+  - LATIN SMALL LETTER OU (`U+0223`);
+  - LATIN SMALL LETTER ALPHA (`U+0251`);
+  - LATIN SMALL LETTER GAMMA (`U+0263`);
+  - LATIN SMALL LETTER RAMS HORN (`U+0264`);
+  - LATIN SMALL LETTER TURNED OPEN E (`U+1D08`);
+  - LATIN LETTER SMALL CAPITAL OU (`U+1D15`);
+  - LATIN LETTER AIN (`U+1D25`);

font-src/glyphs/common/shapes.ptl

@@ -10,6 +10,9 @@ glyph-module
 glyph-block CommonShapes : begin
 	glyph-block-import Common-Derivatives
 
+	glyph-block-export no-shape
+	define [no-shape] { .__isNoShape true }
+
 	glyph-block-export Rect
 	define [Rect u d l r transformShiftOnly] : glyph-proc
 		local giz currentGlyph.gizmo

font-src/glyphs/letter/greek/lower-epsilon.ptl

@@ -191,7 +191,7 @@ glyph-block Letter-Greek-Lower-Epsilon : begin
 	alias 'grek/epsilon' 0x3B5 'latn/epsilon.serifless'
 	select-variant 'latn/Epsilon' 0x190
 	select-variant 'latn/epsilon' 0x25B
-	turned 'turnepsilon' 0x1D08 'grek/epsilon' Middle (XH / 2)
+	turned 'turnepsilon' 0x1D08 'latn/epsilon' Middle (XH / 2)
 	alias 'cyrl/ZeRev' 0x510 'latn/Epsilon'
 	alias 'cyrl/zeRev' 0x511 'latn/epsilon'
 

font-src/glyphs/letter/latin-ext/ou.ptl

@@ -9,36 +9,31 @@ glyph-block Letter-Latin-OU : begin
 	glyph-block-import CommonShapes
 	glyph-block-import Common-Derivatives
 
-	define [UpperOuShape top] : glyph-proc
+	define [OuShape top yBar gapL gapR] : glyph-proc
-		include : OShape (top * HBarPos + HalfStroke) 0 SB RightSB nothing ArchDepthA ArchDepthB
+		include : OShape (yBar + HalfStroke) 0 SB RightSB nothing ArchDepthA ArchDepthB
+
+		local xLeft : clamp (SB + 1.25 * HVContrast * Stroke) [mix SB RightSB 0.4] (Middle - Width * 0.05)
+		local d : 0.25 * TanSlope * (RightSB - SB)
 		include : dispiro
 			widths.lhs
-			flat SB top [heading Downward]
+			g4.left.start (xLeft - CorrectionOMidS) (top - gapL)
-			curl SB (top * HBarPos - O - HalfStroke + ArchDepthB)
-			arcvh
-			g4 (Middle + CorrectionOMidS) (top * HBarPos - O - HalfStroke + (Stroke * (1 - CThin))) [widths.lhs (Stroke * CThin)]
 			archv
-			flat RightSB (top * HBarPos - O - HalfStroke + ArchDepthA) [widths.lhs]
+			g4.down.mid SB ([mix (yBar - HalfStroke) (top - gapL) 0.5] + d)
-			curl RightSB top [heading Upward]
+			arcvh
+			g4 (Middle + CorrectionOMidS) (yBar - O - HalfStroke + (Stroke * (1 - CThin))) [widths.lhs (Stroke * CThin)]
+			archv
+			g4.up.mid RightSB ([mix (yBar - HalfStroke) (top - gapR) 0.5] - d) [widths.lhs]
+			arcvh
+			g4.left.end (Width - xLeft - CorrectionOMidS) (top - gapR)
 
 	create-glyph 'OU' 0x222 : glyph-proc
 		include : MarkSet.capital
-		include : UpperOuShape CAP
+		include : OuShape CAP (CAP * HBarPos) (CAP * 0.05) 0
 
 	create-glyph 'smcpOU' 0x1D15 : glyph-proc
 		include : MarkSet.e
-		include : UpperOuShape XH
+		include : OuShape XH (XH * HBarPos) 0 0
 
 	create-glyph 'ou' 0x223 : glyph-proc
 		include : MarkSet.b
-		local bar : StrokeWidthBlend (XH * 0.9) XH
+		include : OuShape Ascender (Ascender * [mix HBarPos (XH / CAP) 0.5]) 0 0
-		include : OShape bar 0 SB RightSB
-		include : dispiro
-			widths.lhs
-			flat SB Ascender [heading Downward]
-			curl SB (bar - O - Stroke + ArchDepthB)
-			arcvh
-			g4 (Middle + CorrectionOMidS) (bar - O - Stroke + (Stroke * (1 - CThin))) [widths.lhs (Stroke * CThin)]
-			archv
-			flat RightSB (bar - O - Stroke + ArchDepthA) [widths.lhs]
-			curl RightSB Ascender [heading Upward]

font-src/glyphs/letter/latin-ext/rams-horn.ptl

@@ -8,8 +8,9 @@ glyph-module
 glyph-block Letter-Latin-Rams-Horn : begin
 	glyph-block-import CommonShapes
 	glyph-block-import Common-Derivatives
+	glyph-block-import Letter-Shared-Shapes : SerifFrame
 
-	define [RamsHornShape bottom top] : glyph-proc
+	define [LatinGammaShape bottom top] : glyph-proc
 		local hf : [AdviceStroke 4] / 2
 		local d : hf * 2 + Width * 0.05
 
@@ -27,38 +28,60 @@ glyph-block Letter-Latin-Rams-Horn : begin
 
 	create-glyph 'latn/gamma' 0x263 : glyph-proc
 		include : MarkSet.p
-		include : RamsHornShape Descender XH
+		include : LatinGammaShape Descender XH
+		if SLAB : begin
+			local sf : SerifFrame XH Descender SB RightSB
+			include : composite-proc sf.lt.full sf.rt.full
 
 	create-glyph 'latn/Gamma' 0x194 : glyph-proc
 		include : MarkSet.capDesc
-		include : RamsHornShape Descender Ascender
+		include : LatinGammaShape Descender CAP
+		if SLAB : begin
+			local sf : SerifFrame CAP Descender SB RightSB
+			include : composite-proc sf.lt.full sf.rt.full
+
+	define [RamsHornShape fFill bottom top] : glyph-proc
+		local k1 0.625
+		local k2 0.7
+		local kIntersection 0.15
+		local d : 0.25 * (RightSB - SB) * k1 * TanSlope
+
+		local sw   : AdviceStroke : if SLAB 3    2.75
+		local fine : AdviceStroke : if SLAB 3.75 3.5
+		local coFine : mix sw fine (kIntersection / k2)
+		local fillOffset : sw * 0.25
+
+		include : union
+			dispiro
+				widths.rhs sw
+				straight.right.start SB top [heading Rightward]
+				g4 Middle [mix top bottom kIntersection] [widths.rhs coFine]
+				g4.down.mid [mix Middle RightSB k1] ([mix top bottom k2] - d) [widths.rhs fine]
+				arcvh
+				g4.left.mid (Middle + CorrectionOMidX * fine) (bottom + O)
+				archv
+				g4.up.mid [mix Middle SB k1] ([mix top bottom k2] + d)
+				g4 Middle [mix top bottom kIntersection] [widths.rhs coFine]
+				straight.right.end RightSB top [widths.rhs.heading sw Rightward]
+			if fFill
+				then : spiro-outline
+					corner Middle ([mix top bottom kIntersection] - fillOffset)
+					g4.down.mid ([mix Middle RightSB k1] - fillOffset) ([mix top bottom k2] - d)
+					g4.left.mid (Middle + CorrectionOMidX * fine) (bottom + fillOffset)
+					g4.up.mid ([mix Middle SB k1] + fillOffset) ([mix top bottom k2] + d)
+					close
+				else : no-shape
+
+		if SLAB : begin
+			include : DownwardLeftSerif  SB      (top - sw) (VJut * (sw / Stroke) - sw) fine
+			include : DownwardRightSerif RightSB (top - sw) (VJut * (sw / Stroke) - sw) fine
 
 	create-glyph 'ramshorn' 0x264 : glyph-proc
 		include : MarkSet.e
-		include : RamsHornShape 0 XH
+		include : RamsHornShape false 0 XH
 
 	### Ayin
 	create-glyph 'latinAyin' 0x1D25 : glyph-proc
 		include : MarkSet.e
-		local k1 0.65
+		include : RamsHornShape true 0 XH
-		local k2 0.7
+		include : FlipAround Middle (XH / 2)
-		local zmidy (XH * 0.15)
-		local offset : Stroke * 0.25
-		include : union
-			dispiro
-				widths.lhs
-				g4.right.start SB 0 [heading Rightward]
-				g4 Middle zmidy
-				g4.up.mid [mix Middle RightSB k1] (XH * k2) [heading Upward]
-				arcvh
-				g4.left.mid Middle (XH - O) [heading Leftward]
-				archv
-				g4.down.mid [mix Middle SB k1] (XH * k2) [heading Downward]
-				g4 Middle zmidy
-				g4.right.end RightSB 0 [heading Rightward]
-			spiro-outline
-				corner Middle (zmidy + offset)
-				g4.up.mid ([mix Middle RightSB k1] - offset) (XH * k2)
-				g4.left.mid Middle (XH - offset)
-				g4.down.mid ([mix Middle SB k1] + offset) (XH * k2)
-				close

font-src/glyphs/letter/latin/lower-a.ptl

@@ -202,17 +202,31 @@ glyph-block Letter-Latin-Lower-A : begin
 				corner (RightSB - Stroke * HVContrast) (CAP - Stroke / 2)
 				corner RightSB (CAP - O)
 
-	create-glyph 'scripta' 0x0251 : glyph-proc
+	define [CutRightStroke g] : difference g : spiro-outline
-		include : MarkSet.e
+		corner RightSB XH
-		include : union
+		corner (RightSB - Stroke * HVContrast) XH
-			OBarRightShape
+		corner (RightSB - Stroke * HVContrast) (XH - Stroke / 2)
-			spiro-outline
-				corner RightSB 0
-				corner (RightSB - Stroke * HVContrast) 0
-				corner (RightSB - Stroke * HVContrast) (XH - Stroke / 2)
-				corner RightSB (XH - O)
-		if SLAB : include : tagged 'serifRB' RightwardBottomSerif RightSB 0 SideJut
 
+	create-glyph 'scripta.serifless' : glyph-proc
+		include : MarkSet.e
+		set-base-anchor 'trailing' RightSB 0
+		include : OBarRightShape
+		include : CutRightStroke : VBarRight RightSB 0 XH
+
+	create-glyph 'scripta.serifed' : glyph-proc
+		include : MarkSet.e
+		set-base-anchor 'trailing' (RightSB + SideJut) 0
+		include : OBarRightShape
+		include : VBarRight RightSB 0 XH
+		include : tagged 'serifRB' : CutRightStroke : RightwardBottomSerif RightSB 0 SideJut
+
+	create-glyph 'scripta.tailed' : glyph-proc
+		include : MarkSet.e
+		set-base-anchor 'trailing' (RightSB + SideJut) 0
+		include : OBarRightShape
+		include : CutRightStroke : RightwardTailedBar RightSB 0 XH
+
+	select-variant 'scripta' 0x0251
 	turned 'turnlargescripta' 0x2C70 'largescripta' Middle (CAP / 2)
 	turned 'turnscripta' 0x252 'scripta' Middle (XH / 2)
 

font-src/meta/macros.ptl

@@ -133,19 +133,19 @@ define-macro glyph-block-import : syntax-rules
 			derive-composites link-reduced-variant alias-reduced-variant glyph-is-needed
 			HalfAdvance TurnMarks derive-multi-part-glyphs DeriveMeshT]
 
-			CommonShapes `[Rect SquareAt Ring RingAt DotAt RingStroke RingStrokeAt DotStrokeAt
+			CommonShapes `[no-shape Rect SquareAt Ring RingAt DotAt RingStroke RingStrokeAt
-			CircleRing CircleRingAt CircleDotAt RoundStrokeTerminalAt OShapeT OShape OShapeOutline
+			DotStrokeAt CircleRing CircleRingAt CircleDotAt RoundStrokeTerminalAt OShapeT OShape
-			OShapeFlatTB OBarLeftShape OBarRightShape LeftwardTopSerif LeftwardBottomSerif
+			OShapeOutline OShapeFlatTB OBarLeftShape OBarRightShape LeftwardTopSerif
-			RightwardTopSerif RightwardBottomSerif CenterTopSerif CenterTopSerifAsymmetric
+			LeftwardBottomSerif RightwardTopSerif RightwardBottomSerif CenterTopSerif
-			CenterBottomSerif CenterBottomSerifAsymmetric DownwardRightSerif UpwardRightSerif
+			CenterTopSerifAsymmetric CenterBottomSerif CenterBottomSerifAsymmetric
-			DownwardLeftSerif UpwardLeftSerif NeedSlab NeedNotItalic HBar HBarTop HBarBottom
+			DownwardRightSerif UpwardRightSerif DownwardLeftSerif UpwardLeftSerif NeedSlab
-			HOverlayBar VBar VBarLeft VBarRight VerticalHook LeftHook FlatSlashShape hookstart
+			NeedNotItalic HBar HBarTop HBarBottom HOverlayBar VBar VBarLeft VBarRight VerticalHook
-			hookend Ungizmo Regizmo FlipAround ScaleAround Realign ForceUpright DiagCor NameUni
+			LeftHook FlatSlashShape hookstart hookend Ungizmo Regizmo FlipAround ScaleAround Realign
-			PointingTo WithTransform clear-anchors OBarLeftToothlessShape OBarLeftRoundedShape
+			ForceUpright DiagCor NameUni PointingTo WithTransform clear-anchors
-			OBarRightToothlessShape OBarRightRoundedShape AsRadical ExtLineCenter ExtLineLhs
+			OBarLeftToothlessShape OBarLeftRoundedShape OBarRightToothlessShape
-			ExtLineRhs DiagCorDs HCrossBar VERY-FAR MaskAbove MaskBelow MaskLeft MaskRight
+			OBarRightRoundedShape AsRadical ExtLineCenter ExtLineLhs ExtLineRhs DiagCorDs HCrossBar
-			HalfRectTriangle MaskAboveLine MaskBelowLine MaskLeftLine MaskRightLine DotVariants
+			VERY-FAR MaskAbove MaskBelow MaskLeft MaskRight HalfRectTriangle MaskAboveLine
-			WithDotVariants]
+			MaskBelowLine MaskLeftLine MaskRightLine DotVariants WithDotVariants]
 
 		define vartiableFilter : if externEnv.$glyphBlockVariableUsage$
 			lambda [x] externEnv.$glyphBlockVariableUsage$.(x)

font-src/support/glyph/index.mjs

@@ -63,6 +63,8 @@ export class Glyph {
 			return this.applyTransform(component, copyAnchors);
 		} else if (component instanceof Glyph) {
 			return this.includeGlyph(component, copyAnchors, copyWidth);
+		} else if (component.__isNoShape) {
+			// Do nothing. By design.
 		} else {
 			throw new Error("Invalid component to be introduced.");
 		}

params/variants.toml

@@ -1785,6 +1785,7 @@ selector.a = "doubleStoreySerifless"
 selector."a/sansSerif" = "doubleStoreySerifless"
 selector."a/rtailBase" = "doubleStoreySerifless"
 selector."a/turnABase" = "doubleStoreySerifless"
+selector.scripta       = "serifless"
 
 [prime.a.variants.double-storey-tailed]
 rank = 2
@@ -1793,6 +1794,7 @@ selector.a = "doubleStoreyTailed"
 selector."a/sansSerif" = "doubleStoreyTailed"
 selector."a/rtailBase" = "doubleStoreySerifless"
 selector."a/turnABase" = "doubleStoreyTailed"
+selector.scripta       = "tailed"
 
 [prime.a.variants.double-storey-toothless-corner]
 rank = 3
@@ -1801,6 +1803,7 @@ selector.a = "doubleStoreyToothlessCorner"
 selector."a/sansSerif" = "doubleStoreyToothlessCorner"
 selector."a/rtailBase" = "doubleStoreySerifless"
 selector."a/turnABase" = "doubleStoreyToothlessCorner"
+selector.scripta       = "serifless"
 
 [prime.a.variants.double-storey-toothless-rounded]
 rank = 4
@@ -1809,6 +1812,7 @@ selector.a = "doubleStoreyToothlessRounded"
 selector."a/sansSerif" = "doubleStoreyToothlessRounded"
 selector."a/rtailBase" = "doubleStoreySerifless"
 selector."a/turnABase" = "doubleStoreyToothlessRounded"
+selector.scripta       = "serifless"
 
 [prime.a.variants.double-storey-serifed]
 rank = 5
@@ -1817,6 +1821,7 @@ selector.a = "doubleStoreySerifed"
 selector."a/sansSerif" = "doubleStoreySerifless"
 selector."a/rtailBase" = "doubleStoreySerifless"
 selector."a/turnABase" = "doubleStoreySerifed"
+selector.scripta       = "serifed"
 
 [prime.a.variants.single-storey-serifless]
 rank = 6
@@ -1825,6 +1830,7 @@ selector.a = "singleStoreySerifless"
 selector."a/sansSerif" = "singleStoreySerifless"
 selector."a/rtailBase" = "singleStoreySerifless"
 selector."a/turnABase" = "doubleStoreySerifless"
+selector.scripta       = "serifless"
 
 [prime.a.variants.single-storey-earless-corner-serifless]
 rank = 7
@@ -1833,6 +1839,7 @@ selector.a = "singleStoreyEarlessCornerSerifless"
 selector."a/sansSerif" = "singleStoreyEarlessCornerSerifless"
 selector."a/rtailBase" = "singleStoreyEarlessCornerSerifless"
 selector."a/turnABase" = "doubleStoreySerifless"
+selector.scripta       = "serifless"
 
 [prime.a.variants.single-storey-earless-rounded-serifless]
 rank = 8
@@ -1841,6 +1848,7 @@ selector.a = "singleStoreyEarlessRoundedSerifless"
 selector."a/sansSerif" = "singleStoreyEarlessRoundedSerifless"
 selector."a/rtailBase" = "singleStoreyEarlessRoundedSerifless"
 selector."a/turnABase" = "doubleStoreySerifless"
+selector.scripta       = "serifless"
 
 [prime.a.variants.single-storey-tailed]
 rank = 9
@@ -1849,6 +1857,7 @@ selector.a = "singleStoreyTailed"
 selector."a/sansSerif" = "singleStoreyTailed"
 selector."a/rtailBase" = "singleStoreySerifless"
 selector."a/turnABase" = "doubleStoreyTailed"
+selector.scripta       = "tailed"
 
 [prime.a.variants.single-storey-earless-corner-tailed]
 rank = 10
@@ -1857,6 +1866,7 @@ selector.a = "singleStoreyEarlessCornerTailed"
 selector."a/sansSerif" = "singleStoreyEarlessCornerTailed"
 selector."a/rtailBase" = "singleStoreyEarlessCornerSerifless"
 selector."a/turnABase" = "doubleStoreyTailed"
+selector.scripta       = "tailed"
 
 [prime.a.variants.single-storey-earless-rounded-tailed]
 rank = 11
@@ -1865,6 +1875,7 @@ selector.a = "singleStoreyEarlessRoundedTailed"
 selector."a/sansSerif" = "singleStoreyEarlessRoundedTailed"
 selector."a/rtailBase" = "singleStoreyEarlessRoundedSerifless"
 selector."a/turnABase" = "doubleStoreyTailed"
+selector.scripta       = "tailed"
 
 [prime.a.variants.single-storey-serifed]
 rank = 12
@@ -1873,6 +1884,7 @@ selector.a = "singleStoreySerifed"
 selector."a/sansSerif" = "singleStoreySerifless"
 selector."a/rtailBase" = "singleStoreySerifless"
 selector."a/turnABase" = "doubleStoreySerifed"
+selector.scripta       = "serifed"
 
 [prime.a.variants.single-storey-earless-corner-serifed]
 rank = 13
@@ -1881,6 +1893,7 @@ selector.a = "singleStoreyEarlessCornerSerifed"
 selector."a/sansSerif" = "singleStoreyEarlessCornerSerifless"
 selector."a/rtailBase" = "singleStoreyEarlessCornerSerifless"
 selector."a/turnABase" = "doubleStoreySerifed"
+selector.scripta       = "serifed"
 
 [prime.a.variants.single-storey-earless-rounded-serifed]
 rank = 14
@@ -1889,6 +1902,7 @@ selector.a = "singleStoreyEarlessRoundedSerifed"
 selector."a/sansSerif" = "singleStoreyEarlessRoundedSerifless"
 selector."a/rtailBase" = "singleStoreyEarlessRoundedSerifless"
 selector."a/turnABase" = "doubleStoreySerifed"
+selector.scripta       = "serifed"
 
 
 [prime.b]