Commit 7ebd1b7

.. class:: Line2

Defines a two-dimensional directed line segment defined by two points.

This class is mostly used as a way to cache information that is

regularly required when working on geometrical problems.

.. note::

Lines should be used as if they were completely immutable to ensure

correctness. All attributes of Line2 can be reconstructed from the two

points, and thus cannot be changed on their own and must be recalculated

if there were any changes to `start` or `end`.

.. note::

To prevent unnecessary recalculations, many functions on lines accept an

'offset' argument, which is used to perform calculations on lines that

are simply shifts of other lines.

.. attribute:: Line2.start

`Vector2` the start of this line

.. attribute:: Line2.end

`Vector2` the end of this line

.. attribute:: Line2.delta

`Vector2` from start to end

.. attribute:: Line2.axis

`Vector2` normalized `delta`

.. attribute:: Line2.normal

`Vector2` normalized normal of `axis`

.. attribute:: Line2.magnitude_squared

`numerical` square of the magnitude of the line

.. attribute:: Line2.magnitude

`numerical` magnitude of the line

.. attribute:: Line2.min_x

`numerical` minimum x-value on the line

.. attribute:: Line2.min_y

`numerical` minimum y-value on the line

.. attribute:: Line2.max_x

`numerical` maximum x-value on the line

.. attribute:: Line2.max_y

`numerical` maximum y-value on the line

.. attribute:: Line2.slope

`numerical` (including +inf and -inf) slope of the line

.. attribute:: Line2.y_intercept

`numerical or None` y_intercept of the line (or None if `vertical`)

.. attribute:: Line2.horizontal

`bool` true if ``slope == 0``, false otherwise

.. attribute:: Line2.vertical

`bool` true if ``slope == float('+inf') or slope == float('-inf')``, false otherwise

.. staticmethod:: intersects_line(line1, line2, offset1, offset2)

- **line1** - `Line2` first line

- **line2** - `Line2` second line

- **offset1** - `Vector2` offset of first line

- **offset2** - `Vector2` offset of second line

- **Return Value** - `bool, bool` touches, overlaps

Determines if the two lines at the specified offsets are touching and/or

overlapping. Two lines touch if they share endpoints, two lines overlap

if they intersect on any point that is not an endpoint.