Add config winMetricPad

meta/aesthetics.ptl

@@ -170,6 +170,7 @@ export : define [setFontMetrics para metrics font] : begin
 	define asc : para.leading * CAP / (CAP - DESCENDER)
 	define desc : para.leading * DESCENDER / (CAP - DESCENDER)
 	define descenderPad : fallback para.descenderPad 0
+	define winMetricPad : fallback para.winMetricPad 0
 
 	set font.OS_2.xAvgCharWidth     WIDTH
 	set font.head.unitsPerEm        1000
@@ -178,8 +179,8 @@ export : define [setFontMetrics para metrics font] : begin
 	set font.OS_2.sTypoAscender     asc
 
 	set font.hhea.descender         (DESCENDER - descenderPad)
-	set font.OS_2.usWinDescent      ([Math.abs desc] + descenderPad)
-	set font.OS_2.sTypoDescender    (desc - descenderPad)
+	set font.OS_2.usWinDescent      ([Math.abs desc] + descenderPad + winMetricPad)
+	set font.OS_2.sTypoDescender    (desc - descenderPad + winMetricPad)
 
 	set font.hhea.lineGap           0
 	set font.OS_2.sTypoLineGap      0

parameters.toml

@@ -11,6 +11,7 @@ width = 500        # Character width. Increase this if you think that Iosevka is
 cap = 735          # Cap height (as well as ascender).
 xheight = 530      # X-height.
 #descender = -205  # Depth of descender. Currently unused.
+winMetricPad = 0   # Padding of Win metrics to avoid clipping. See #343
 
 ideoMid  = 365
 symbolMid = 365    # Center of parens, maths, geometrics...
@@ -412,6 +413,22 @@ leading = 1750
 [leading-2000]
 leading = 2000
 
+###### Win metric pad
+[win-metric-pad-0]
+winMetricPad = 0
+[win-metric-pad-50]
+winMetricPad = 50
+[win-metric-pad-100]
+winMetricPad = 100
+[win-metric-pad-150]
+winMetricPad = 150
+[win-metric-pad-200]
+winMetricPad = 200
+[win-metric-pad-250]
+winMetricPad = 250
+[win-metric-pad-300]
+winMetricPad = 300
+
 ###### Powerline
 [powerline-scale-y-750]
 powerlineScaleY = 0.75