Merge pull request #768 from googlefonts/not-all-quadratic

add allQuadratic=False option to allow building glyf v1 with cubics
googlefonts · Jul 28, 2023 · 1ff885d · 1ff885d
2 parents 6003361 + fc1d8d3
commit 1ff885d
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Showing 7 changed files with 337 additions and 2 deletions.
diff --git a/Lib/ufo2ft/__init__.py b/Lib/ufo2ft/__init__.py
@@ -225,6 +225,7 @@ def compileOTF(ufo, **kwargs):
         flattenComponents=False,
         autoUseMyMetrics=True,
         dropImpliedOnCurves=False,
+        allQuadratic=True,
     ),
 }
 
@@ -252,13 +253,20 @@ def compileTTF(ufo, **kwargs):
 
     *dropImpliedOnCurves* (bool) specifies whether on-curve points that are exactly
     in between two off-curves can be dropped when building glyphs (default: False).
+
+    *allQuadratic* (bool) specifies whether to convert all curves to quadratic - True
+    by default, builds traditional glyf v0 table. If False, quadratic curves or cubic
+    curves are generated depending on which has fewer points; a glyf v1 is generated.
     """
     kwargs = init_kwargs(kwargs, compileTTF_args)
 
     glyphSet = call_preprocessor(ufo, **kwargs)
 
     logger.info("Building OpenType tables")
-    otf = call_outline_compiler(ufo, glyphSet, **kwargs)
+
+    otf = call_outline_compiler(
+        ufo, glyphSet, glyphDataFormat=(0 if kwargs["allQuadratic"] else 1), **kwargs
+    )
 
     # Only the default layer is likely to have all glyphs used in feature code.
     if kwargs["layerName"] is None:
@@ -280,6 +288,7 @@ def compileTTF(ufo, **kwargs):
         colrAutoClipBoxes=False,
         extraSubstitutions=None,
         autoUseMyMetrics=True,
+        allQuadratic=True,
     ),
 }
 
@@ -327,6 +336,7 @@ def compileInterpolatableTTFs(ufos, **kwargs):
             ufo,
             glyphSet,
             **kwargs,
+            glyphDataFormat=(0 if kwargs["allQuadratic"] else 1),
             tables=SPARSE_TTF_MASTER_TABLES if layerName else None,
             # we want to keep coordinates as floats in glyf masters so that fonttools
             # can compute impliable on-curve points from unrounded coordinates before
@@ -562,6 +572,7 @@ def compileFeatures(
         colrAutoClipBoxes=False,
         autoUseMyMetrics=True,
         dropImpliedOnCurves=False,
+        allQuadratic=True,
     ),
 }
 
@@ -612,6 +623,10 @@ def compileVariableTTFs(designSpaceDoc: DesignSpaceDocument, **kwargs):
       to build. If not provided, all variable fonts listed in the given
       designspace will by built.
 
+    *allQuadratic* (bool) specifies whether to convert all curves to quadratic - True
+      by default, builds traditional glyf v0 table. If False, quadratic curves or cubic
+      curves are generated depending on which has fewer points; a glyf v1 is generated.
+
     The rest of the arguments works the same as in the other compile functions.
 
     Returns a dictionary that maps each variable font filename to a new variable

diff --git a/Lib/ufo2ft/filters/cubicToQuadratic.py b/Lib/ufo2ft/filters/cubicToQuadratic.py
@@ -14,6 +14,7 @@ class CubicToQuadraticFilter(BaseFilter):
         "conversionError": None,
         "reverseDirection": True,
         "rememberCurveType": False,
+        "allQuadratic": True,
     }
 
     def set_context(self, font, glyphSet):
@@ -64,6 +65,7 @@ def filter(self, glyph):
             self.context.absoluteError,
             reverse_direction=self.options.reverseDirection,
             stats=self.context.stats,
+            all_quadratic=self.options.allQuadratic,
         )
         contours = list(glyph)
         glyph.clearContours()

diff --git a/Lib/ufo2ft/outlineCompiler.py b/Lib/ufo2ft/outlineCompiler.py
@@ -363,7 +363,7 @@ def setupTable_head(self):
         )
         head.fontDirectionHint = 2
         head.indexToLocFormat = 0
-        head.glyphDataFormat = 0
+        head.glyphDataFormat = getattr(self, "glyphDataFormat", 0)
 
     def setupTable_name(self):
         """
@@ -1440,6 +1440,7 @@ def __init__(
         dropImpliedOnCurves=False,
         autoUseMyMetrics=True,
         roundCoordinates=True,
+        glyphDataFormat=0,
     ):
         super().__init__(
             font,
@@ -1454,6 +1455,7 @@ def __init__(
         self.autoUseMyMetrics = autoUseMyMetrics
         self.dropImpliedOnCurves = dropImpliedOnCurves
         self.roundCoordinates = roundCoordinates
+        self.glyphDataFormat = glyphDataFormat
 
     def compileGlyphs(self):
         """Compile and return the TrueType glyphs for this font."""

diff --git a/Lib/ufo2ft/preProcessor.py b/Lib/ufo2ft/preProcessor.py
@@ -195,6 +195,7 @@ def initDefaultFilters(
         flattenComponents=False,
         convertCubics=True,
         conversionError=None,
+        allQuadratic=True,
         reverseDirection=True,
         rememberCurveType=True,
     ):
@@ -227,6 +228,7 @@ def initDefaultFilters(
                     conversionError=conversionError,
                     reverseDirection=reverseDirection,
                     rememberCurveType=rememberCurveType and self.inplace,
+                    allQuadratic=allQuadratic,
                 )
             )
         return filters
@@ -266,6 +268,7 @@ def __init__(
         layerNames=None,
         skipExportGlyphs=None,
         filters=None,
+        allQuadratic=True,
     ):
         from fontTools.cu2qu.ufo import DEFAULT_MAX_ERR
 
@@ -293,6 +296,7 @@ def __init__(
         ]
         self._reverseDirection = reverseDirection
         self._rememberCurveType = rememberCurveType
+        self.allQuadratic = allQuadratic
 
         self.defaultFilters = []
         for ufo in ufos:
@@ -336,6 +340,7 @@ def process(self):
             reverse_direction=self._reverseDirection,
             dump_stats=True,
             remember_curve_type=self._rememberCurveType and self.inplace,
+            all_quadratic=self.allQuadratic,
         )
 
         # TrueType fonts cannot mix contours and components, so pick out all glyphs

diff --git a/tests/data/TestFont-not-allQuadratic.ttx b/tests/data/TestFont-not-allQuadratic.ttx
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ttFont>
+
+  <glyf>
+
+    <!-- The xMin, yMin, xMax and yMax values
+         will be recalculated by the compiler. -->
+
+    <TTGlyph name=".notdef" xMin="50" yMin="0" xMax="450" yMax="750">
+      <contour>
+        <pt x="450" y="0" on="1"/>
+        <pt x="50" y="0" on="1"/>
+        <pt x="50" y="750" on="1"/>
+        <pt x="450" y="750" on="1"/>
+      </contour>
+      <contour>
+        <pt x="400" y="50" on="1"/>
+        <pt x="400" y="700" on="1"/>
+        <pt x="100" y="700" on="1"/>
+        <pt x="100" y="50" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0020"/><!-- contains no outline data -->
+
+    <TTGlyph name="uni0061" xMin="66" yMin="0" xMax="322" yMax="510">
+      <contour>
+        <pt x="66" y="0" on="1"/>
+        <pt x="194" y="510" on="1"/>
+        <pt x="322" y="0" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0062" xMin="100" yMin="-5" xMax="310" yMax="505">
+      <contour>
+        <pt x="100" y="505" on="1"/>
+        <pt x="310" y="505" on="1"/>
+        <pt x="310" y="-5" on="1"/>
+        <pt x="100" y="-5" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0063" xMin="100" yMin="-10" xMax="300" yMax="500">
+      <contour>
+        <pt x="300" y="-10" on="1"/>
+        <pt x="150" y="-10" on="0" cubic="1"/>
+        <pt x="100" y="40" on="0" cubic="1"/>
+        <pt x="100" y="245" on="1"/>
+        <pt x="100" y="450" on="0" cubic="1"/>
+        <pt x="150" y="500" on="0" cubic="1"/>
+        <pt x="300" y="500" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0064" xMin="90" yMin="77" xMax="211" yMax="197">
+      <contour>
+        <pt x="151" y="197" on="1"/>
+        <pt x="184" y="197" on="0" cubic="1"/>
+        <pt x="211" y="170" on="0" cubic="1"/>
+        <pt x="211" y="137" on="1"/>
+        <pt x="211" y="104" on="0" cubic="1"/>
+        <pt x="184" y="77" on="0" cubic="1"/>
+        <pt x="151" y="77" on="1"/>
+        <pt x="117" y="77" on="0" cubic="1"/>
+        <pt x="90" y="104" on="0" cubic="1"/>
+        <pt x="90" y="137" on="1"/>
+        <pt x="90" y="170" on="0" cubic="1"/>
+        <pt x="117" y="197" on="0" cubic="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0065" xMin="-55" yMin="23" xMax="454" yMax="510">
+      <contour>
+        <pt x="66" y="510" on="1"/>
+        <pt x="322" y="510" on="1"/>
+        <pt x="194" y="75" on="1"/>
+      </contour>
+      <contour>
+        <pt x="-55" y="23" on="1"/>
+        <pt x="-55" y="173" on="0" cubic="1"/>
+        <pt x="-5" y="223" on="0" cubic="1"/>
+        <pt x="199" y="223" on="1"/>
+        <pt x="404" y="223" on="0" cubic="1"/>
+        <pt x="454" y="173" on="0" cubic="1"/>
+        <pt x="454" y="23" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0066" xMin="-55" yMin="23" xMax="454" yMax="510">
+      <contour>
+        <pt x="66" y="510" on="1"/>
+        <pt x="194" y="75" on="1"/>
+        <pt x="322" y="510" on="1"/>
+      </contour>
+      <contour>
+        <pt x="-55" y="23" on="1"/>
+        <pt x="-55" y="173" on="0" cubic="1"/>
+        <pt x="-5" y="223" on="0" cubic="1"/>
+        <pt x="199" y="223" on="1"/>
+        <pt x="404" y="223" on="0" cubic="1"/>
+        <pt x="454" y="173" on="0" cubic="1"/>
+        <pt x="454" y="23" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0067" xMin="66" yMin="0" xMax="322" yMax="510">
+      <component glyphName="uni0061" x="0" y="0" flags="0x204"/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0068" xMin="100" yMin="-5" xMax="310" yMax="657">
+      <component glyphName="uni0064" x="60" y="460" flags="0x4"/>
+      <component glyphName="uni0062" x="0" y="0" flags="0x204"/>
+    </TTGlyph>
+
+    <TTGlyph name="uni0069" xMin="-55" yMin="-80" xMax="454" yMax="510">
+      <contour>
+        <pt x="-55" y="-80" on="1"/>
+        <pt x="-55" y="69" on="0" cubic="1"/>
+        <pt x="-5" y="119" on="0" cubic="1"/>
+        <pt x="199" y="119" on="1"/>
+        <pt x="404" y="119" on="0" cubic="1"/>
+        <pt x="454" y="69" on="0" cubic="1"/>
+        <pt x="454" y="-80" on="1"/>
+      </contour>
+      <contour>
+        <pt x="66" y="0" on="1"/>
+        <pt x="194" y="510" on="1"/>
+        <pt x="322" y="0" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni006A" xMin="-55" yMin="-280" xMax="454" yMax="230">
+      <contour>
+        <pt x="-55" y="-80" on="1"/>
+        <pt x="-55" y="69" on="0" cubic="1"/>
+        <pt x="-5" y="119" on="0" cubic="1"/>
+        <pt x="199" y="119" on="1"/>
+        <pt x="404" y="119" on="0" cubic="1"/>
+        <pt x="454" y="69" on="0" cubic="1"/>
+        <pt x="454" y="-80" on="1"/>
+      </contour>
+      <contour>
+        <pt x="66" y="230" on="1"/>
+        <pt x="322" y="230" on="1"/>
+        <pt x="194" y="-280" on="1"/>
+      </contour>
+      <instructions/>
+    </TTGlyph>
+
+    <TTGlyph name="uni006B" xMin="66" yMin="0" xMax="422" yMax="510">
+      <component glyphName="uni0061" x="0" y="0" flags="0x4"/>
+      <component glyphName="uni0061" x="100" y="0" flags="0x4"/>
+    </TTGlyph>
+
+    <TTGlyph name="uni006C" xMin="78" yMin="0" xMax="422" yMax="510">
+      <component glyphName="uni0061" x="400" y="0" scalex="-1.0" scaley="1.0" flags="0x4"/>
+      <component glyphName="uni0061" x="100" y="0" flags="0x4"/>
+    </TTGlyph>
+
+  </glyf>
+
+</ttFont>