Docs: Add intro to Edges

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Florian Festi 2018-08-27 17:38:18 +02:00
parent 65152efdd1
commit f15fedd2e2
1 changed files with 24 additions and 4 deletions

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Edges
=====
Edges are what makes Boxes.py work. They draw a -- more or less -- straight
border to the current piece. They are part of the turtle graphics part
of Boxes.py. This means they start at the current position and current
direction and move the current position to the end of the edge.
Edge instances have a Settings object associated with them that keeps
the details about how the edge should look like. Edges that are
supposed to work together share the same Settings object to ensure
they fit together - assuming they have the same length. Most edges are
symetrical to unsure they fit together even when drawn from different
directions. Although there are a few exception - mainly edges that
provide special features like hinges.
As edges started out as methods of the main Boxes class they still are
callables. A set of instances are kept the ``.edges`` attribute of the
callables. It turned out that the edges need to provide a bit more
information to allow the surrounding code to handle them
properly. When drawing an Edge there is a virtual straight line that
is the border the shape of the part (e.g. an rectangle). But the
actual Edge has often to be drawn elsewhere. Best example if probably
the ``F`` Edge that matches the normal finger joints. It has to start
one material thickness outside of the virual border of the part so the
cutouts for the opposing fingers just touch the border. The Edge
classes have a number of methods to deal with these kind of offsets.
A set of instances are kept the ``.edges`` attribute of the
``Boxes`` class. It is a dict with strings of length one as keys:
* d : DoveTailJoint
@ -18,9 +41,6 @@ callables. A set of instances are kept the ``.edges`` attribute of the
* s : StackableEdge
* S : StackableEdgeTop
Edges of the same type share a settings instance to make sure both
sides match (when the same length is given).
Edge base class
---------------