# Software 3D Renderer

## Features

* OBJ model import
* Depth buffering
* Texture mapping with bilinear filtering
* Lighting (ambient, diffuse, specular)
* Smooth shading

## Goals

### Implement basic GPU pipeline in software

To best learn what a GPU is doing, I wanted to recreate the functionality
of the GPU in software. It's not anywhere near as fast as a GPU of course,
but it's not slow either (for a single model that is relatively low-poly).

### Simple code

Coming from a C background, I wanted to use features of C++ that I found made
the code cleaner and easier to understand while avoiding many of the fancier
ones that seemed unnecessary. Primarily I leveraged operator overloading for
vector and matrix operations, and used some simple classes with constructors.

### Good cache performance

The biggest bottleneck of modern CPU performance is latency between memory and
the CPU, so I tried to use spatial and temporal locality to keep data in the cache.
Although I chose to go for array-of-structs instead of struct-of-arrays, the
cache miss rate is fairly low.

### Minimal libraries

I created my own *very* basic OBJ loader (rather than use `tinyobj`) to better
understand how OBJ files are constructed, along with their respective MTL files.
I also wrote my own linear algebra functions and classes (rather than use `glm`)
to better understand the low-level math operations.