add more docs to README

README.md

@@ -1,28 +1,95 @@
 Aniray
 ======
-Aniray is a library for animating and orchestrating large arrays of emitters, actuators, displays, and more.
+[Aniray](https://github.com/HypersonicED/aniray) is a library for animating and
+orchestrating large arrays of emitters, actuators, displays, and more.
+
+**NOTE:** This library is under active development and is currently prone to
+large breaking changes. Following the first release Aniray will conform to
+semantic versioning.
+
+## Principles
+
+- **Large Installation Focused:** Aniray is a one-stop solution for large
+  systems individual parts. Object placement and hardware configuration are
+  configured separately from the code so that they may change freely as
+  projects change during development.
+- **Visualization Independent:** Many installations of lights and actuators
+  don't include a screen output. Aniray is not built specifically for any other
+  graphics toolkit (i.e. Cinder or openFrameworks). These frameworks may be
+  used alongside Aniray but are not required.
+- **Standards Driven, Hardware Independent:** Exact hardware components vary
+  from project to project, and sometimes original parts aren't available when
+  repairs are necessary. Rather than picking specific or proprietary products,
+  this library aims to support broadly-supported standards that allow for the
+  most flexibility.
+- **Abstracted and Extensible:** Most C++ classes in Aniray provide support for
+  a particular function or task are extended from broader base classes. This
+  promotes user extensibility of Aniray and open source contribution to the
+  library.
+- **Time-based Processing:** Tasks are performed in reference to time, not
+  frames. This allows for a consistent experience across hardware platforms of
+  varying processing power. If a machine is not up to the task, then it will be
+  immediately obvious instead of slowing down.
+
+## Key Terminology
+ - **Node:** A Node is a control point in an installation in physical space.
+   This may be a LED pixel, an actuator assembly, some other output device, or
+   a combination of these. For example, in a series of winches that move up and
+   down each winch is a Node with a vertical axis control. If there are lights
+   at the end of the winches, then the combination of the light and winch is
+   still one Node (where the node has a vertical position and color outputs).
+   If there are lights not specific to each winch, then these would be separate
+   Nodes. Nodes may be tied to a physical output or used virtually in
+   animations to inform physical Nodes.
+ - **Node Array:** A Node Array is group of Nodes. A Node Array can be
+   initialized from a list of positions and addresses. A Node Array can also be
+   generated by creating a dense 3D grid around another Node Array.
+ - **Node Array Output:** A Node Array Output ties a Node Array to a physical
+   output device.
+ - **Node Array Sampler:** A Node Array Sampler allows for sampling values from
+   a dense Node Array to inform a less-dense Node Array. The sampling mapping
+   can be found automatically by distance or can be defined statically.
+ - **Input Interface:** An Input Interface is an interface to inputs to the
+   application. These can be discrete, counters, integers, etc.
 
 ## Features
 
 - Automatic subsampling node grid generation and caching
 - Load node physical data from CSV
 - Visualization framework independent (can be used with Cinder, oFx, etc.)
-- Open Lighting Architecture (OLA) for lighting output allowing for robust many universe outputs of E1.31 (sACN), Artnet, KiNET, USB DMX adapters, and more.
+- Open Lighting Architecture (OLA) for lighting output allowing for robust many
+  universe outputs of E1.31 (sACN), Artnet, KiNET, USB DMX adapters, and more.
 - Extensible output classes for other output methods
+- Modbus support receiving inputs separate from nodes
+- Extensible IO classes for other input and output methods
+- Threaded runners for receiving inputs and sending frames at fixed rates
+- Boost Geometry types for graphics-independent transformations
+- Templated data structs and output transformations for nodes
+
+## Planned Features
+ - Node-specific animation queues
+ - Thorough Doxygen documentation
+ - Thread safety for all methods, not just methods always used in threads
 
 ## Requirements
 
+- Only tested on Linux, but may work on other platforms
 - C++17
 - clang or gcc, untested on other platforms
 - Boost >= 1.74.0 (Boost Software License)
 - OpenSSL >= 1.1.0 (OpenSSL License)
-- libola >= 0.10.8 (LGPL) or turn off with `-DANIRAY_WITHOUT_OLA=ON` and bring your own output
+- libola >= 0.10.8 (LGPL) or turn off with `-DANIRAY_WITHOUT_OLA=ON` and bring
+  or contribute your own output
+- libmodbus >= 3.1.6 (LGPL) or turn off with `-DANIRAY_WITHOUT_MODBUS=ON` and
+  or contribute bring your own IO
 - Bundled requirements (Git submodules):
-  - [ben-strasser/fast-cpp-csv-parser](https://github.com/ben-strasser/fast-cpp-csv-parser) (BSD-3-Clause License)
+  - [ben-strasser/fast-cpp-csv-parser](
+    https://github.com/ben-strasser/fast-cpp-csv-parser) (BSD-3-Clause License)
 
 ## Build and Lint Requirements
 
 - CMake
+- pkg-config
 - `iwyu` (include-what-you-use) with `-DANIRAY_WITH_LINT=ON`
 - `clang-tidy` with `-DANIRAY_WITH_LINT=ON`
 
@@ -33,13 +100,14 @@ Aniray is a library for animating and orchestrating large arrays of emitters, ac
    ```bash
    git clone --recursive https://github.com/HypersonicED/aniray.git
    ```
-3. Either
+3. Either:
    - Add to your `CMakeLists.txt`
    - Build the static library
      ```bash
      cmake -H. -B_builds/Release -DCMAKE_BUILD_TYPE=Release
      ```
-   - Build the shared library
+   - Build the shared library (NOTE: This is not usually useful due to
+     templated types)
      ```bash
      cmake -H. -B_builds/Release -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON
      ```