Add separate match compare function for size

Has two distinctions from FcCompareRange():
1. As best value, it returns query pattern size, even if it's out of font range,
2. Implements semi-closed interval, as that's what OS/2 v5 table defines

src/fcmatch.c

@@ -219,6 +219,55 @@ FcCompareRange (const FcValue *v1, const FcValue *v2, FcValue *bestValue)
 	return 0.0;
 }
 
+static double
+FcCompareSize (const FcValue *v1, const FcValue *v2, FcValue *bestValue)
+{
+    FcValue value1 = FcValueCanonicalize (v1);
+    FcValue value2 = FcValueCanonicalize (v2);
+    double b1, e1, b2, e2;
+
+    switch ((int) value1.type) {
+    case FcTypeInteger:
+        b1 = e1 = value1.u.i;
+	break;
+    case FcTypeDouble:
+        b1 = e1 = value1.u.d;
+	break;
+    case FcTypeRange:
+	abort();
+	b1 = value1.u.r->begin;
+	e1 = value1.u.r->end;
+	break;
+    default:
+	return -1;
+    }
+    switch ((int) value2.type) {
+    case FcTypeInteger:
+        b2 = e2 = value2.u.i;
+	break;
+    case FcTypeDouble:
+        b2 = e2 = value2.u.d;
+	break;
+    case FcTypeRange:
+	b2 = value2.u.r->begin;
+	e2 = value2.u.r->end;
+	break;
+    default:
+	return -1;
+    }
+
+    bestValue->type = FcTypeDouble;
+    bestValue->u.d = (b1 + e1) * .5;
+
+    /* If the ranges overlap, it's a match, otherwise return closest distance. */
+    if (e1 < b2 || e2 < b1)
+	return FC_MIN (fabs (b2 - e1), fabs (b1 - e2));
+    if (b2 != e2 && b1 == e2) /* Semi-closed interval. */
+        return 1e-15;
+    else
+	return 0.0;
+}
+
 static double
 FcCompareFilename (const FcValue *v1, const FcValue *v2, FcValue *bestValue)
 {
@@ -250,6 +299,7 @@ FcCompareFilename (const FcValue *v1, const FcValue *v2, FcValue *bestValue)
 #define PRI_FcCompareLang(n)		PRI1(n)
 #define PRI_FcComparePostScript(n)	PRI1(n)
 #define PRI_FcCompareRange(n)		PRI1(n)
+#define PRI_FcCompareSize(n)		PRI1(n)
 
 #define FC_OBJECT(NAME, Type, Cmp)	PRI_##Cmp(NAME)
 

src/fcobjs.h

@@ -31,7 +31,7 @@ FC_OBJECT (FULLNAMELANG,	FcTypeString,	NULL)
 FC_OBJECT (SLANT,		FcTypeInteger,	FcCompareNumber)
 FC_OBJECT (WEIGHT,		FcTypeRange,	FcCompareRange)
 FC_OBJECT (WIDTH,		FcTypeRange,	FcCompareRange)
-FC_OBJECT (SIZE,		FcTypeRange,	FcCompareRange)
+FC_OBJECT (SIZE,		FcTypeRange,	FcCompareSize)
 FC_OBJECT (ASPECT,		FcTypeDouble,	NULL)
 FC_OBJECT (PIXEL_SIZE,		FcTypeDouble,	FcCompareNumber)
 FC_OBJECT (SPACING,		FcTypeInteger,	FcCompareNumber)