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h1. Introduction
This manual focuses on the lib2geom computational geometry framework.
The main goal of this framework is the eventual replacement of
Inkscape's multiple and shoddy geometry frameworks. As with any decent
module or lib, 2geom is designed to achieve the desired functionality
while maintaining a generality encouraging usage within other
applications. The focus on robust, accurate algorithms, as well as
utilization of newer and better representations makes the lib
very attractive for many applications.
h2. Design Considerations
2Geom is written with a functional programming style in mind.
Generally data structures are considered immutable and rather than
assignment we use labeling. However, C++ can become unwieldy if
this is taken to extreme and so a certain amount of pragmatism is
used in practice. In particular, usability is not forgotten in the
mires of functional zeal.
The code relies strongly on the type system and uses some of the more
'tricky' elements of C++ to make the code more elegant and 'correct'.
Despite this, the intended use of 2Geom is a serious vector graphics
application. In such domains, performance is still used as a quality
metric, and as such we consider inefficiency to be a bug, and have
traded elegance for efficiency where it matters.
In general the data structures used in 2Geom are relatively 'flat'
and require little from the memory management. Currently most data
structures are built on standard STL headers, and new and delete are
used sparingly. It is intended for 2Geom to be fully compatible with
Boehm garbage collector though this has not yet been tested.
h2. Toy-Based Development
We have managed to come up with a method of library development
which is perfect for geometry - the development of toys exemplifying
a feature while the feature is perfected. This has somewhat subsumed
the role of tests, and provides immediate motivation/reward for work.
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