HACKING

"There's a difference between knowing the path... and walking the path."
    -Morpheus

neo is a program written in C++ that uses the ncursesw library to control
the terminal. It is built using autotools.

The code is split mostly into three files:

neo.cpp - Handles the main loop, command-line options, and initializing ncurses.
cloud.cpp - Implements the Cloud class, which manages all the Droplets.
droplet.cpp - Implements the Droplet class, which moves/draws the characters.

The application's main loop creates a single Cloud object that manages all
the Droplets. Each Droplet is responsible for moving and drawing a vertical
string of characters. Cloud and Droplet are tightly coupled. It is expected
that Cloud should call into each Droplet's methods, but several Droplet
methods call back into Cloud. This is one possible area for improvement.
Cloud also keeps track of the color and glitch status for each character on
screen.

neo makes heavy use of the "pool" idiom, which is more commonly seen in game
development. Rather than allocating objects on the fly, neo allocates many
objects, disabling and reusing them as needed. For example, neo allocates as
many Droplets as it needs whenever Cloud is reset. neo also uses a pool for the
characters that are drawn to the screen. Each Droplet has an index into this
pool of random characters.

neo does a few other tricks to improve performance. The main one is that it
tries to draw as few characters as possible per frame rather than drawing
every character onscreen. To do this, each Droplet keeps track of a "CurLine"
position and a "PutLine". CurLine indicates the last line that was drawn on
the last frame. PutLine indicates the last line that must be drawn this frame.

The code is not idiomatic modern C++. There are many uses of older C functions
such as fprintf(), strtok(), etc. In general, the style is a hodge-podge of
C++11 with older C idioms and a liberal use of cstdint types with an avoidance
of lambdas, streams, templates, and overusing the "auto" keyword. The code
makes some use of the newer C++11 chrono and random libraries. K&R C bracing
is the norm, as are soft tabs.

If you submit a pull request, please avoid adding additional dependencies
and make sure any relevant documentation has also been added or updated.

Ideas for contribution:

    - Fix any open issue on GitHub
    - Refactor Cloud to better follow SOLID OOP principles
    - Make Cloud a proper singleton
    - Use one mt19937 object per distribution for better independence
    - Add more parameters to --charset (e.g. Chinese)
    - Performance improvements