[type] Add HBFixed template
diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index 523dba5..e66f451 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -141,27 +141,24 @@
/* 16-bit unsigned integer (HBUINT16) that describes a quantity in FUnits. */
typedef HBUINT16 UFWORD;
-/* 16-bit signed fixed number with the low 14 bits of fraction (2.14). */
-struct F2DOT14 : HBINT16
+template <typename Type, unsigned fraction_bits>
+struct HBFixed : Type
{
- F2DOT14& operator = (uint16_t i ) { HBINT16::operator= (i); return *this; }
- // 16384 means 1<<14
- float to_float () const { return ((int32_t) v) / 16384.f; }
- void set_float (float f) { v = roundf (f * 16384.f); }
+ static constexpr float shift = (float) (1 << fraction_bits);
+ static_assert (Type::static_size * 8 > fraction_bits, "");
+
+ HBFixed& operator = (typename Type::type i ) { Type::operator= (i); return *this; }
+ float to_float () const { return ((int32_t) Type::v) / shift; }
+ void set_float (float f) { Type::v = roundf (f * shift); }
public:
- DEFINE_SIZE_STATIC (2);
+ DEFINE_SIZE_STATIC (Type::static_size);
};
+/* 16-bit signed fixed number with the low 14 bits of fraction (2.14). */
+using F2DOT14 = HBFixed<HBINT16, 14>;
+
/* 32-bit signed fixed-point number (16.16). */
-struct F16DOT16 : HBINT32
-{
- F16DOT16& operator = (uint32_t i) { HBINT32::operator= (i); return *this; }
- // 65536 means 1<<16
- float to_float () const { return ((int32_t) v) / 65536.f; }
- void set_float (float f) { v = roundf (f * 65536.f); }
- public:
- DEFINE_SIZE_STATIC (4);
-};
+using F16DOT16 = HBFixed<HBINT32, 16>;
/* Date represented in number of seconds since 12:00 midnight, January 1,
* 1904. The value is represented as a signed 64-bit integer. */
