Files
shattered-pixel-dungeon-web…/SPD-classes/src/main/java/com/watabou/utils/Graph.java
2025-05-13 12:53:08 -04:00

108 lines
2.3 KiB
Java

/*
* Pixel Dungeon
* Copyright (C) 2012-2015 Oleg Dolya
*
* Shattered Pixel Dungeon
* Copyright (C) 2014-2025 Evan Debenham
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
*/
package com.watabou.utils;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
public class Graph {
public static <T extends Node> void setPrice( List<T> nodes, int value ) {
for (T node : nodes) {
node.price( value );
}
}
public static <T extends Node> void buildDistanceMap( Collection<T> nodes, Node focus ) {
for (T node : nodes) {
node.distance( Integer.MAX_VALUE );
}
LinkedList<Node> queue = new LinkedList<>();
focus.distance( 0 );
queue.add( focus );
while (!queue.isEmpty()) {
Node node = queue.poll();
int distance = node.distance();
int price = node.price();
for (Node edge : node.edges()) {
if (edge.distance() > distance + price) {
queue.add( edge );
edge.distance( distance + price );
}
}
}
}
@SuppressWarnings("unchecked")
public static <T extends Node> List<T> buildPath( Collection<T> nodes, T from, T to ) {
List<T> path = new ArrayList<>();
T room = from;
while (room != to) {
int min = room.distance();
T next = null;
Collection<? extends Node> edges = room.edges();
for (Node edge : edges) {
int distance = edge.distance();
if (distance < min) {
min = distance;
next = (T)edge;
}
}
if (next == null) {
return null;
}
path.add( next );
room = next;
}
return path;
}
public interface Node {
int distance();
void distance( int value );
int price();
void price( int value );
Collection<? extends Node> edges();
}
}