README Arthur Berman, Max Bernstein, Thomas Colgrove, Kate Wasynczuk

Code overview

We have a significant number of modules, utility classes, and some bundled requirements.

Modules

Collector: collector.h, collector.cpp Collector is a networked producer of coordinate ranges and consumer of pixels. It acts as a TCP server and serves coordinates to Workers that request it. It also fields requests from Workers submitting pixels.

Worker: worker.h, worker.cpp Worker is a networked consumer of coordinate ranges and producer of pixels. It acts as a TCP client and sends pixels to Collectors.

WorkQueue: work_queue.h, work_queue.cpp WorkQueue is a circular queue with constant-time insert, remove, and lookup. It ensures that Collector processes work with extreme fault tolerance and speed.

RayTracer: ray_tracer.h, ray_tracer.cpp RayTracer is the class that controls all of the actual rendering, PnmImage manipulation, and file writing. The core work done by the RayTracer starts in cast_ray, which takes a ray and calculates the illumination at the first point it hits. This calculation is handled by calculate_illumination, which calls calculate_diffuse, calculate_reflection, and calculate_refraction to determine the different impacts of light on the point.

Parser: parser.h, parser.cpp Parser is responsible for the management of scene description files. Our scene descriptions are stored in JavaScript Object Notation (JSON), and Parser loads, parses, and creates in-memory representations of the scenes. RayTracer uses Parser.

SceneObject: scene_object.h SceneObject is the overarching virtual class in the 3D object class heirarchy. It contains traits such as loc for location, material for material, and methods such as get_location() and get_normal(). Sphere, PointLight, and Box all inherit from this class.

Our File Format: In JSON, we represent our scene as two lists: scene_objects and scene_lights. Scene_objects contains objects representing figures in the scene, while scene_lights describes the illuminations.

TCPServer: util/tcp/tcp_server.{h,cpp} C++ does not have a built-in or easily bundled TCP server implementation, so we wrote our own. It supports only basic functions like start, serve_request, and stop. It is created with a callback function of signature string -> string that handles all requests.

TCPClient: util/tcp/tcp_client.{h,cpp} C++ also does not have a built-in or easily bundled TCP client implementation, so we wrote our own. It supports only basic functions like connect, send_data, and receive.

PnmImage: util/pnm/pnm_image.{h,cpp} PnmImage is responsible for the creation and writing of collections of pixels to disk. RayTracer manages a PnmImage, both alone and in Collector.