ED_LRR/docs/src/ed-lrr.md

---
# Metadata
title: ED_LRR
author:
- Daniel Seiller <earthnuker@gmail.com>
subtitle: 'Elite Dangerous: Long-Range Router'

# Formating
toc: true
lang: en
colorlinks: true
papersize: a4
numbersections: true

#Panflute options
panflute-filters: [multifilter]
panflute-path: 'filters'

#Template options
titlepage: true
toc-own-page: false
---

\pagebreak

# Implementation

## `stars.csv` format

### Columns

| Name      | Content                                                      |
| --------- | ------------------------------------------------------------ |
| id        | unique ID-Number (not equal to id or id64, just a sequential number) |
| star_type | Type of Star                                                 |
| system    | Name of System                                               |
| body      | Name of Star                                                 |
| mult      | Jump Range Multiplier (1.5 for White Dwarfs, 4.0 for Neutron Stars) |
| distance  | Distance from arrival in Ls                                  |
| x,y,z     | Position in Galactic Coordinates with Sol at (0,0,0)         |

## `stars.idx` format

`bincode` serialized data:

- **[u64]**: List of byte offset for records (entry 0=first recod, entry 1= second record, etc)

## Routing Algorithms

### Breadth-First Search (BFS)

Standard Breadth-First Search, always finds the shortest route

### A*-Search

Modified A*-Search with adjustable "greediness". Priority Queue weighted by $\text{number of jumps from start system} + (\text{estimated number of jumps to target system} * \text{greediness})$

A greediness of 0 is equivalent to BFS and a greediness of $\infty$ is equivalent to Greedy-Search

### Greedy-Search

Priority Queue weighted by minimum distance to target, prefers systems with high multiplier (Neutron Stars and White Dwarfs)

## Optimizations

### Ellipse elimination

Only consider systems within an ellipsoid with source and destination as the foci, the width of the ellipsoid is adjustable

## Routing Graphs

### File format

`bincode` serialized data:

- *bool* **primary**: flag to indicate that graph only includes primary stars
- *f32* **range**: jump range for routing graph
- *[u8]* **file_hash**: sha3 hash of `stars.csv` from which graph was generated
- *String* **path**: path to `stars.csv` from which graph was generated
- *FnvHashMap* **graph**: Hashmap mapping systems to the systems from which they can be rached, traversed from destination system backwards to source to reconstruct route

# Usage

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TODO: Add screenshots
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## Preprocessing Data

## Plotting a Route

# [Changelog](https://gitlab.com/Earthnuker/ed_lrr/blob/pyqt_gui/CHANGELOG.md)