here_be_dragons/src/metric.rs

90 lines
2.6 KiB
Rust

//! Different metrics for the map
//! Can be used to meausre the quality of the map or the quality of the generator.
//! To meause the quality of the generator; generate lots of maps, measure them
//! and the provide generator score as an average.
//!
use super::dijkstra::DijkstraMap;
use super::map::Map;
/// This metric calculates the percentage of walkable cells (Floor).
/// If this number is very low (like < 10%) then it means that the map
/// is probably to degenerated and shouldn't be used
pub fn density<D: Clone + Default>(map: &Map<D>) -> f32 {
let floor_count = map.tiles.iter().filter(|&t| t.is_walkable()).count();
floor_count as f32 / map.tiles.len() as f32
}
/// Calculate the length of the shortes path from the starting point
/// to the exit.
/// If this path is very short, then the map is probably degenerated.
pub fn path_length<D: Clone + Default>(map: &Map<D>) -> f32 {
if map.starting_point.is_none() {
return 0.0;
}
match map.exit_point {
None => 0.0,
Some(exit) => {
let dijkstra = DijkstraMap::new(map);
dijkstra.tiles[map.xy_idx(exit.x, exit.y)]
}
}
}
/// ------------------------------------------------------------------------------------------------
/// Module unit tests
/// ------------------------------------------------------------------------------------------------
#[cfg(test)]
mod tests {
use super::*;
use crate::{geometry::Point, map::NoData};
#[test]
fn test_density_no_floor() {
let map = Map::<NoData>::new(10, 10);
let score = density(&map);
assert_eq!(score, 0.0);
}
#[test]
fn test_density() {
let map_str = "
##########
# ## #
##########
";
let map = Map::<NoData>::from_string(map_str);
let score = density(&map);
assert_eq!(score, 0.2);
}
#[test]
fn test_no_path() {
let map_str = "
##########
# ## #
##########
";
let map = Map::<NoData>::from_string(map_str);
let score = path_length(&map);
assert_eq!(score, 0.0);
}
#[test]
fn test_path_length() {
let map_str = "
##########
# ## #
# #
##########
";
let mut map = Map::<NoData>::from_string(map_str);
map.starting_point = Some(Point::new(1, 1));
map.exit_point = Some(Point::new(8, 1));
let score = path_length(&map);
assert!(f32::abs(score - 7.9) <= 0.01);
}
}