From ac8b70af2ba78ef4aa2b61a6eab72fd29095c0e1 Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Fri, 17 Dec 2021 10:44:35 -0500
Subject: [PATCH] Add nearest neighbor corridor builder

---
 src/map_builders.rs                         |  2 +
 src/map_builders/rooms_corridors_nearest.rs | 66 +++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 src/map_builders/rooms_corridors_nearest.rs

diff --git a/src/map_builders.rs b/src/map_builders.rs
index 649fda9..29464cb 100644
--- a/src/map_builders.rs
+++ b/src/map_builders.rs
@@ -18,6 +18,7 @@ mod room_exploder;
 mod room_sorter;
 mod rooms_corridors_bsp;
 mod rooms_corridors_dogleg;
+mod rooms_corridors_nearest;
 mod simple_map;
 mod voronoi;
 mod voronoi_spawning;
@@ -43,6 +44,7 @@ use room_exploder::RoomExploder;
 use room_sorter::{RoomSort, RoomSorter};
 use rooms_corridors_bsp::BspCorridors;
 use rooms_corridors_dogleg::DoglegCorridors;
+use rooms_corridors_nearest::NearestCorridors;
 use simple_map::SimpleMapBuilder;
 use specs::prelude::*;
 use voronoi::VoronoiCellBuilder;
diff --git a/src/map_builders/rooms_corridors_nearest.rs b/src/map_builders/rooms_corridors_nearest.rs
new file mode 100644
index 0000000..33832d9
--- /dev/null
+++ b/src/map_builders/rooms_corridors_nearest.rs
@@ -0,0 +1,66 @@
+use std::collections::HashSet;
+
+use rltk::RandomNumberGenerator;
+
+use super::common::draw_corridor;
+use super::{BuilderMap, MetaMapBuilder};
+use crate::Rect;
+
+pub struct NearestCorridors {}
+
+impl MetaMapBuilder for NearestCorridors {
+    #[allow(dead_code)]
+    fn build_map(&mut self, rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
+        self.corridors(rng, build_data);
+    }
+}
+
+impl NearestCorridors {
+    #[allow(dead_code)]
+    pub fn new() -> Box<NearestCorridors> {
+        Box::new(NearestCorridors {})
+    }
+
+    fn corridors(&mut self, _rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
+        let rooms: Vec<Rect>;
+        if let Some(rooms_builder) = &build_data.rooms {
+            rooms = rooms_builder.clone();
+        } else {
+            panic!("Nearest Corridors requires a builder with room structures");
+        }
+
+        let mut connected: HashSet<usize> = HashSet::new();
+        for (i, room) in rooms.iter().enumerate() {
+            let mut room_distance: Vec<(usize, f32)> = Vec::new();
+            let room_center = room.center();
+            let room_center_pt = rltk::Point::new(room_center.0, room_center.1);
+
+            for (j, other_room) in rooms.iter().enumerate() {
+                if i != j && !connected.contains(&j) {
+                    let other_center = other_room.center();
+                    let other_center_pt = rltk::Point::new(other_center.0, other_center.1);
+                    let distance =
+                        rltk::DistanceAlg::Pythagoras.distance2d(room_center_pt, other_center_pt);
+
+                    room_distance.push((j, distance));
+                }
+            }
+
+            if !room_distance.is_empty() {
+                room_distance.sort_by(|a, b| a.1.partial_cmp(&b.1).unwrap());
+                let dest_center = rooms[room_distance[0].0].center();
+
+                draw_corridor(
+                    &mut build_data.map,
+                    room_center.0,
+                    room_center.1,
+                    dest_center.0,
+                    dest_center.1,
+                );
+
+                connected.insert(i);
+                build_data.take_snapshot();
+            }
+        }
+    }
+}