instancer_test: test instancing HVAR table

Aldo added AdvWidthMap to PartialInstancer-VF.ttx test font

Tests/varLib/data/PartialInstancerTest-VF.ttx

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<ttFont sfntVersion="\x00\x01\x00\x00" ttLibVersion="3.39">
+<ttFont sfntVersion="\x00\x01\x00\x00" ttLibVersion="3.40">
 
   <GlyphOrder>
     <!-- The 'id' attribute is only for humans; it is ignored when parsed. -->
@@ -12,12 +12,12 @@
     <!-- Most of this table will be recalculated by the compiler -->
     <tableVersion value="1.0"/>
     <fontRevision value="2.001"/>
-    <checkSumAdjustment value="0x9184e88f"/>
+    <checkSumAdjustment value="0x9180a393"/>
     <magicNumber value="0x5f0f3cf5"/>
     <flags value="00000000 00000011"/>
     <unitsPerEm value="1000"/>
     <created value="Tue Mar  5 00:05:14 2019"/>
-    <modified value="Sat Apr 20 14:38:56 2019"/>
+    <modified value="Sat Apr 20 17:03:24 2019"/>
     <xMin value="40"/>
     <yMin value="-200"/>
     <xMax value="450"/>
@@ -570,7 +570,7 @@
       </VarRegionList>
       <!-- VarDataCount=1 -->
       <VarData index="0">
-        <!-- ItemCount=3 -->
+        <!-- ItemCount=2 -->
         <NumShorts value="0"/>
         <!-- VarRegionCount=5 -->
         <VarRegionIndex index="0" value="2"/>
@@ -578,11 +578,15 @@
         <VarRegionIndex index="2" value="4"/>
         <VarRegionIndex index="3" value="5"/>
         <VarRegionIndex index="4" value="6"/>
-        <Item index="0" value="[0, 0, 0, 0, 0]"/>
+        <Item index="0" value="[-4, -48, -11, 31, 55]"/>
-        <Item index="1" value="[-4, -48, -11, 31, 55]"/>
+        <Item index="1" value="[0, 0, 0, 0, 0]"/>
-        <Item index="2" value="[0, 0, 0, 0, 0]"/>
       </VarData>
     </VarStore>
+    <AdvWidthMap>
+      <Map glyph=".notdef" outer="0" inner="1"/>
+      <Map glyph="hyphen" outer="0" inner="0"/>
+      <Map glyph="space" outer="0" inner="1"/>
+    </AdvWidthMap>
   </HVAR>
 
   <MVAR>

Tests/varLib/instancer_test.py

@@ -277,6 +277,62 @@ class InstantiateMVARTest(object):
         assert "MVAR" not in varfont
 
 
+class InstantiateHVARTest(object):
+    # the 'expectedDeltas' below refer to the VarData item deltas for the "hyphen"
+    # glyph in the PartialInstancerTest-VF.ttx test font, that are left after
+    # partial instancing
+    @pytest.mark.parametrize(
+        "location, expectedRegions, expectedDeltas",
+        [
+            ({"wght": -1.0}, [{"wdth": (-1.0, -1.0, 0)}], [-59]),
+            ({"wght": 0}, [{"wdth": (-1.0, -1.0, 0)}], [-48]),
+            ({"wght": 1.0}, [{"wdth": (-1.0, -1.0, 0)}], [7]),
+            (
+                {"wdth": -1.0},
+                [
+                    {"wght": (-1.0, -1.0, 0.0)},
+                    {"wght": (0.0, 0.61, 1.0)},
+                    {"wght": (0.61, 1.0, 1.0)},
+                ],
+                [-11, 31, 51],
+            ),
+            ({"wdth": 0}, [{"wght": (0.61, 1.0, 1.0)}], [-4]),
+        ],
+    )
+    def test_partial_instance(
+        self, varfont, fvarAxes, location, expectedRegions, expectedDeltas
+    ):
+        instancer.instantiateHVAR(varfont, location)
+
+        assert "HVAR" in varfont
+        hvar = varfont["HVAR"].table
+        varStore = hvar.VarStore
+
+        regions = varStore.VarRegionList.Region
+        assert [reg.get_support(fvarAxes) for reg in regions] == expectedRegions
+
+        assert len(varStore.VarData) == 1
+        assert varStore.VarData[0].ItemCount == 2
+
+        assert hvar.AdvWidthMap is not None
+        advWithMap = hvar.AdvWidthMap.mapping
+
+        assert advWithMap[".notdef"] == advWithMap["space"]
+        varIdx = advWithMap[".notdef"]
+        # these glyphs have no metrics variations in the test font
+        assert varStore.VarData[varIdx >> 16].Item[varIdx & 0xFFFF] == (
+            [0] * varStore.VarData[0].VarRegionCount
+        )
+
+        varIdx = advWithMap["hyphen"]
+        assert varStore.VarData[varIdx >> 16].Item[varIdx & 0xFFFF] == expectedDeltas
+
+    def test_full_instance(self, varfont):
+        instancer.instantiateHVAR(varfont, {"wght": 0, "wdth": 0})
+
+        assert "HVAR" not in varfont
+
+
 class InstantiateItemVariationStoreTest(object):
     def test_VarRegion_get_support(self):
         axisOrder = ["wght", "wdth", "opsz"]