# n64
Experimental low-level N64 emulator

![Build](https://github.com/Dillonb/n64/workflows/Build/badge.svg)
[![Documentation Status](https://readthedocs.org/projects/n64/badge/?version=latest)](https://n64.readthedocs.io/?badge=latest)

![Mario Face](https://raw.githubusercontent.com/Dillonb/n64/master/screenshots/mario.png)

# What is this?
This is a project I am working on to learn about the N64 and more advanced emulation techniques.

# What is this not?
- This is NOT intended to be your "daily driver" N64 emulator for gaming, at least it is currently not planned to be.

# Links
- [Compatibility List](https://github.com/Dillonb/n64/projects/2)
- [My Test Suite](https://github.com/dillonb/n64-tests)
- [My Documentation](https://n64.readthedocs.io/)

# Goals
## Personal development
- Learn about JIT dynamic recompilers
- Learn about 3D graphics
- Challenge myself

## Technical
- Nothing _exclusively_ using high level emulation (HLE.) If anything is HLE'd, it must be an optional setting.
- GUI debugger to view hardware registers/memory
- GDB stub for debugging
- Reasonable amount of automated testing
- Configurable input, keyboard and gamepad support

# Limitations
- Only Linux is currently supported, as I use Linux-specific features. This is planned to be fixed.
- Only little-endian host platforms are planned to be supported.
- Only gcc is supported for now, but this is for sure planned to be fixed. The binary built with gcc will export symbols for the RDP plugin (loaded as a shared library) to call back into, but the binary built with clang will not.
- Only gcc and clang will be supported. I unapologetically use extensions like case ranges and binary literals.
- RDRAM is stored internally as big-endian and translated on every read/write.
- Only software that uses NTSC video modes is currently supported. This is planned to be fixed.

# Progress

## UI
Basically nonexistent. Runs a simple SDL window and configured with command-line parameters.

## Debugger
Not started. There is verbose logging with -v (repeatable) that provides some debug info, however.

## CPU
Reasonably complete. Not all instructions are there yet, but enough for now. I'm implementing instructions as I come across them in games, so this will slowly progress as time goes on.

An interpreter and a basic cached interpreter are available, able to be switched at compile time by editing a `#define` in n64system.c.

## RSP
Reasonably complete. Fast3d (Super Mario 64) seems to work. There are still bugs in the VRCP family of instructions.

Still greatly in need of optimization.


## RDP
Not started. [My fork of Angrylion](https://github.com/Dillonb/angrylion-rdp-plus) can (and must!) be loaded to provide this functionality in the meantime, however.