use a "smart rounding" algorithm to handle rounding when reducing upm.

glyphs/cyrillic-basic.patel

@@ -48,11 +48,11 @@ define [CyrYeriShape top _left _right _fine] : glyph-construction {
 	include : spiro {
 		widths.lhs fine
 		flat [left + STROKE * 0.2] 0 [heading RIGHTWARD]
-		curl [right - turnbottom * [right - left] / [RIGHTSB - SB]] 0
+		curl [right - turnbottom * [right - left] / [RIGHTSB - SB]] 0 [heading RIGHTWARD]
-		archv
+		archv 8
 		g4   [right - O] turnbottom
-		arcvh
+		arcvh 8
-		flat [right - turnbottom * [right - left] / [RIGHTSB - SB]] bowl
+		flat [right - turnbottom * [right - left] / [RIGHTSB - SB]] bowl [heading LEFTWARD]
 		curl [left + STROKE * 0.2] bowl [heading LEFTWARD]
 	}
 	include : VBarLeft left 0 top fine

glyphs/latin-extend-basis.patel

@@ -101,15 +101,12 @@ create-glyph 'aeapart' : glyph-construction {
 	local sma : SMALLSMOOTHA * 0.6
 	local smb : SMALLSMOOTHB * 0.6
 
-	include : spiro {
-		widths.lhs MVERTSTROKE
-		g4 abarRight [XH - smb]
-		hookend XO 0.5
-		g4 [SB + O] [XH - SHOOK]
-	}
 	include : spiro {
 		widths.rhs MVERTSTROKE
-		g4 abarRight smb
+		g4 [SB + O] [XH - SHOOK]
+		hookstart XO 0.5
+		flat abarRight [XH - smb]
+		curl abarRight smb
 		arcvh
 		g4 lowmiddle O
 		archv

makefile

@@ -13,6 +13,8 @@ PASS0   = $(subst $(OBJDIR)/,$(OBJDIR)/.pass0-,$(TARGETS))
 ABFEAT  = $(subst .ttf,.ab.fea,$(subst $(OBJDIR)/,$(OBJDIR)/.pass0-,$(TARGETS)))
 FEATURE = $(subst .ttf,.fea,$(subst $(OBJDIR)/,$(OBJDIR)/.pass0-,$(TARGETS)))
 PASS1   = $(subst $(OBJDIR)/,$(OBJDIR)/.pass1-,$(TARGETS))
+PASS2   = $(subst $(OBJDIR)/,$(OBJDIR)/.pass2-,$(TARGETS))
+PASS3   = $(subst $(OBJDIR)/,$(OBJDIR)/.pass3-,$(TARGETS))
 
 FILES = $(SUPPORT_FILES) buildglyphs.js
 
@@ -45,7 +47,11 @@ $(FEATURE) : $(OBJDIR)/.pass0-%.fea : $(OBJDIR)/.pass0-%.ab.fea features/common.
 # Pass 1 : Outline cleanup and merge
 $(PASS1) : $(OBJDIR)/.pass1-%.ttf : $(OBJDIR)/.pass0-%.ttf $(OBJDIR)/.pass0-%.fea
 	fontforge -quiet -script pass1-cleanup.py $^ $@ $(SUPPRESS_ERRORS)
-$(TARGETS) : $(OBJDIR)/%.ttf : $(OBJDIR)/.pass1-%.ttf
+$(PASS2) : $(OBJDIR)/.pass2-%.ttf : $(OBJDIR)/.pass1-%.ttf
+	node pass2-smartround.js $^ $@ --upm $(TARGETUPM)
+$(PASS3) : $(OBJDIR)/.pass3-%.ttf : $(OBJDIR)/.pass2-%.ttf
+	fontforge -quiet -script pass3-finalize.py $^ $@ $(TARGETUPM)
+$(TARGETS) : $(OBJDIR)/%.ttf : $(OBJDIR)/.pass3-%.ttf
 	ttfautohint $< $@
 
 update : $(FILES)

pass1-cleanup.py

@@ -5,8 +5,9 @@ import sys
 
 source = sys.argv[1]
 font = fontforge.open(source)
-font.mergeFeature(sys.argv[2])
+
 # Replace accented characters into references
+print "Reference finding: ", font.fontname
 font.selection.select(("ranges", "unicode", None), 0x1FCD, 0x1FCF, 0x1FDD, 0x1FDF)
 font.replaceWithReference(4)
 font.selection.none()
@@ -16,6 +17,9 @@ font.selection.none()
 font.selection.select(("ranges", "unicode", None), 0x0000, 0xFFFF)
 font.replaceWithReference(4)
 font.selection.none()
+
+# Remove overlapped area
+print "Overlap Removal: ", font.fontname
 font.selection.all()
 font.removeOverlap()
 font.round()
@@ -26,18 +30,28 @@ for i in font:
 		glyph.unlinkRef()
 		glyph.removeOverlap()
 
+# Outline simplify
+print "Simplify, pass 1: ", font.fontname
+font.simplify(1)
 font.layers["Fore"].is_quadratic = False
 font.selection.all()
-font.simplify(font.em / 1000.0, ("smoothcurves"), 0.05)
+font.simplify(font.em / 1000.0 * 0.5, ("smoothcurves", "choosehv"), 0.1);
-font.transform(psMat.skew(-font.italicangle / 180 * math.pi))
+
-# convert cubic outlines to quadratic under 1000upm
+print "Simplify, pass 2: ", font.fontname
 oldem = font.em
 font.em = 1000
+font.round()
+font.simplify(0.25)
+font.transform(psMat.skew(-font.italicangle / 180 * math.pi))
 for i in font:
 	font[i].addExtrema(("all"))
+font.simplify(1, ("smoothcurves"), 0.05)
 font.layers["Fore"].is_quadratic = True
-font.round()
+
-font.simplify(1)
+print "Finalize: ", font.fontname
+font.em = oldem
+font.mergeFeature(sys.argv[2])
+
 font.canonicalContours()
 font.canonicalStart()
 font.generate(sys.argv[3], flags = ("short-post", "opentype"))

pass2-smartround.js

@@ -0,0 +1,74 @@
+var fs = require('fs');
+var TTFReader = require('node-sfnt').TTFReader;
+var TTFWriter = require('node-sfnt').TTFWriter;
+
+var argv = require('yargs').argv;
+
+function toArrayBuffer(buffer) {
+	var length = buffer.length;
+	var view = new DataView(new ArrayBuffer(length), 0, length);
+	for (var i = 0, l = length; i < l; i++) {
+		view.setUint8(i, buffer[i], false);
+	}
+	return view.buffer;
+}
+function toBuffer(arrayBuffer) {
+	var length = arrayBuffer.byteLength;
+	var view = new DataView(arrayBuffer, 0, length);
+	var buffer = new Buffer(length);
+	for (var i = 0, l = length; i < l; i++) {
+		buffer[i] = view.getUint8(i, false);
+	}
+	return buffer;
+}
+
+var options = {preserveOS2Version: true, preserveXAvgCharWidth: true, writeUnknownTables: true, hinting: true}
+
+function readttf(file) {
+	var data = fs.readFileSync(file);
+	var buffer = toArrayBuffer(data);
+	var ttf = (new TTFReader(options)).read(buffer);
+	return ttf;
+}
+
+function writettf(ttf, file){
+	var buffer = new TTFWriter(options).write(ttf);
+	fs.writeFileSync(file, toBuffer(buffer));
+}
+function mix(a, b, p){ return a + (b - a) * p }
+function ratio(l, m, r){
+	if(l === r) return 0;
+	return (m - l) / (r - l);
+}
+function colinear(a, b, c){
+	return Math.abs(((c.y - a.y) * (b.x - a.x) - (c.x - a.x) * (b.y - a.y))) <= 1e-5
+}
+var ttf = readttf(argv._[0]);
+var targetupm = argv.upm - 0 || 1000;
+var upm = ttf.head.unitsPerEm - 0;
+var skew = Math.tan(ttf.post.italicAngle / 180 * Math.PI);
+for(var j = 0; j < ttf.glyf.length; j++){
+	var glyph = ttf.glyf[j];
+	if(glyph.contours && glyph.contours.length > 0) for(var k = 0; k < glyph.contours.length; k++) if(glyph.contours[k].length > 0) {
+		var c = glyph.contours[k];
+		for(var l = 0; l < c.length; l++){
+			c[l].x += skew * c[l].y
+		}
+		var xs = c.map(function(p){ return p.x });
+		var ys = c.map(function(p){ return p.y });
+		var xmin = Math.min.apply(null, xs);
+		var xmax = Math.max.apply(null, xs);
+		var ymin = Math.min.apply(null, ys);
+		var ymax = Math.max.apply(null, ys);
+		var rxmin = (upm / targetupm) * Math.round(xmin * targetupm / upm);
+		var rxmax = (upm / targetupm) * Math.round(xmax * targetupm / upm);
+		var rymin = (upm / targetupm) * Math.round(ymin * targetupm / upm);
+		var rymax = (upm / targetupm) * Math.round(ymax * targetupm / upm);
+		for(var l = 0; l < c.length; l++){
+			c[l].y = (upm / targetupm) * Math.round(mix(rymin, rymax, ratio(ymin, c[l].y, ymax)) * targetupm / upm)
+			c[l].x = (upm / targetupm) * Math.round((mix(rxmin, rxmax, ratio(xmin, c[l].x, xmax)) - c[l].y * skew) * targetupm / upm)
+		}
+		glyph.contours[k] = c.filter(function(p){ return !p.removable })
+	}
+}
+fs.writeFileSync(argv._[1], toBuffer(new TTFWriter(options).write(ttf)));

pass3-finalize.py

@@ -0,0 +1,12 @@
+import fontforge
+import psMat
+import sys
+import math
+
+source = sys.argv[1]
+font = fontforge.open(source)
+font.em = int(sys.argv[3])
+font.selection.all()
+font.round()
+font.simplify(0.1)
+font.generate(sys.argv[2], flags = ("short-post", "opentype"))

support/glyph.patel

@@ -80,9 +80,7 @@ define [Glyph.prototype.cubic-to x1 y1 x2 y2 x y] : begin {
 	local lastContour this.contours`[this.contours.length - 1]
 	local lastPoint lastContour`[lastContour.length - 1]
 	local segments : bezierCubic2Q2 lastPoint [tp this.gizmo (.x x1 .y y1)] [tp this.gizmo (.x x2 .y y2)] [tp this.gizmo (.x x .y y)]
-	foreach (p0 (.x xc .y yc) (.x xf .y yf)) [items-of segments] : lastContour.push (.x xc .y yc) #(.x xf .y yf .onCurve true)
+	foreach (p0 (.x xc .y yc) (.x xf .y yf)) [items-of segments] : lastContour.push (.x xc .y yc) (.x xf .y yf .onCurve true)
-	local final segments.[segments.length - 1].2
-	lastContour.push (.x final.x .y final.y .onCurve true)
 	return this
 }
 Glyph.prototype.cubicTo = Glyph.prototype.cubic-to
@@ -196,6 +194,7 @@ define [oncurveRemovable a b c] : begin {
 	return : [not a.onCurve] && b.onCurve && [not c.onCurve] && [a.x <= b.x && b.x <= c.x || a.x >= b.x && b.x >= c.x] && [a.y <= b.y && b.y <= c.y || a.y >= b.y && b.y >= c.y] && [Math.abs [b.x - xm]] <= 0.5 && [Math.abs [b.y - ym]] <= 0.5
 }
 define [Glyph.prototype.cleanup] : begin {
+	return this
 	foreach c [range 0 this.contours.length] : begin {
 		local contour this.contours.(c)
 		local cleanedContour ()

support/toquad.js

@@ -45,7 +45,7 @@ function bezierCubic2Q2(p1, c1, c2, p2, level) {
     var my = p2.y - 3 * c2.y + 3 * c1.y - p1.y;
 
     // control points near
-    if (mx * mx + my * my <= 1 || level > 5) {
+    if (mx * mx + my * my <= 4 || level > 5) {
         return [
             toQuad(p1, c1, c2, p2)
         ];