1 files changed, 143 insertions, 0 deletions
diff --git a/Lib/fontTools/misc/vector.py b/Lib/fontTools/misc/vector.py
new file mode 100644
index 00000000..81c14841
--- /dev/null
+++ b/Lib/fontTools/misc/vector.py
@@ -0,0 +1,143 @@
+from numbers import Number
+import math
+import operator
+import warnings
+
+
+__all__ = ["Vector"]
+
+
+class Vector(tuple):
+
+    """A math-like vector.
+
+    Represents an n-dimensional numeric vector. ``Vector`` objects support
+    vector addition and subtraction, scalar multiplication and division,
+    negation, rounding, and comparison tests.
+    """
+
+    __slots__ = ()
+
+    def __new__(cls, values, keep=False):
+        if keep is not False:
+            warnings.warn(
+                "the 'keep' argument has been deprecated",
+                DeprecationWarning,
+            )
+        if type(values) == Vector:
+            # No need to create a new object
+            return values
+        return super().__new__(cls, values)
+
+    def __repr__(self):
+        return f"{self.__class__.__name__}({super().__repr__()})"
+
+    def _vectorOp(self, other, op):
+        if isinstance(other, Vector):
+            assert len(self) == len(other)
+            return self.__class__(op(a, b) for a, b in zip(self, other))
+        if isinstance(other, Number):
+            return self.__class__(op(v, other) for v in self)
+        raise NotImplementedError()
+
+    def _scalarOp(self, other, op):
+        if isinstance(other, Number):
+            return self.__class__(op(v, other) for v in self)
+        raise NotImplementedError()
+
+    def _unaryOp(self, op):
+        return self.__class__(op(v) for v in self)
+
+    def __add__(self, other):
+        return self._vectorOp(other, operator.add)
+
+    __radd__ = __add__
+
+    def __sub__(self, other):
+        return self._vectorOp(other, operator.sub)
+
+    def __rsub__(self, other):
+        return self._vectorOp(other, _operator_rsub)
+
+    def __mul__(self, other):
+        return self._scalarOp(other, operator.mul)
+
+    __rmul__ = __mul__
+
+    def __truediv__(self, other):
+        return self._scalarOp(other, operator.truediv)
+
+    def __rtruediv__(self, other):
+        return self._scalarOp(other, _operator_rtruediv)
+
+    def __pos__(self):
+        return self._unaryOp(operator.pos)
+
+    def __neg__(self):
+        return self._unaryOp(operator.neg)
+
+    def __round__(self, *, round=round):
+        return self._unaryOp(round)
+
+    def __eq__(self, other):
+        if isinstance(other, list):
+            # bw compat Vector([1, 2, 3]) == [1, 2, 3]
+            other = tuple(other)
+        return super().__eq__(other)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __bool__(self):
+        return any(self)
+
+    __nonzero__ = __bool__
+
+    def __abs__(self):
+        return math.sqrt(sum(x * x for x in self))
+
+    def length(self):
+        """Return the length of the vector. Equivalent to abs(vector)."""
+        return abs(self)
+
+    def normalized(self):
+        """Return the normalized vector of the vector."""
+        return self / abs(self)
+
+    def dot(self, other):
+        """Performs vector dot product, returning the sum of
+        ``a[0] * b[0], a[1] * b[1], ...``"""
+        assert len(self) == len(other)
+        return sum(a * b for a, b in zip(self, other))
+
+    # Deprecated methods/properties
+
+    def toInt(self):
+        warnings.warn(
+            "the 'toInt' method has been deprecated, use round(vector) instead",
+            DeprecationWarning,
+        )
+        return self.__round__()
+
+    @property
+    def values(self):
+        warnings.warn(
+            "the 'values' attribute has been deprecated, use "
+            "the vector object itself instead",
+            DeprecationWarning,
+        )
+        return list(self)
+
+    @values.setter
+    def values(self, values):
+        raise AttributeError(
+            "can't set attribute, the 'values' attribute has been deprecated",
+        )
+
+
+def _operator_rsub(a, b):
+    return operator.sub(b, a)
+
+
+def _operator_rtruediv(a, b):
+    return operator.truediv(b, a)