Files
Mindustry/core/src/mindustry/ai/Pathfinder.java
2020-07-19 12:21:21 -04:00

477 lines
16 KiB
Java

package mindustry.ai;
import arc.*;
import arc.func.*;
import arc.math.geom.*;
import arc.struct.*;
import arc.util.ArcAnnotate.*;
import arc.util.*;
import arc.util.async.*;
import mindustry.annotations.Annotations.*;
import mindustry.game.EventType.*;
import mindustry.game.*;
import mindustry.gen.*;
import mindustry.world.*;
import mindustry.world.meta.*;
import static mindustry.Vars.*;
public class Pathfinder implements Runnable{
private static final long maxUpdate = Time.millisToNanos(6);
private static final int updateFPS = 60;
private static final int updateInterval = 1000 / updateFPS;
private static final int impassable = -1;
private static final int fieldTimeout = 1000 * 60 * 2;
/** tile data, see PathTileStruct */
private int[][] tiles;
/** unordered array of path data for iteration only. DO NOT iterate or access this in the main thread. */
private Seq<Flowfield> threadList = new Seq<>(), mainList = new Seq<>();
/** Maps team ID and target to to a flowfield.*/
private ObjectMap<PathTarget, Flowfield>[] fieldMap = new ObjectMap[Team.all.length];
/** Used field maps. */
private ObjectSet<PathTarget>[] fieldMapUsed = new ObjectSet[Team.all.length];
/** handles task scheduling on the update thread. */
private TaskQueue queue = new TaskQueue();
/** Stores path target for a position. Main thread only.*/
private ObjectMap<Position, PathTarget> targetCache = new ObjectMap<>();
/** Current pathfinding thread */
private @Nullable Thread thread;
private IntSeq tmpArray = new IntSeq();
public Pathfinder(){
Events.on(WorldLoadEvent.class, event -> {
stop();
//reset and update internal tile array
tiles = new int[world.width()][world.height()];
fieldMap = new ObjectMap[Team.all.length];
fieldMapUsed = new ObjectSet[Team.all.length];
targetCache = new ObjectMap<>();
threadList = new Seq<>();
mainList = new Seq<>();
for(Tile tile : world.tiles){
tiles[tile.x][tile.y] = packTile(tile);
}
//special preset which may help speed things up; this is optional
preloadPath(state.rules.waveTeam, FlagTarget.enemyCores);
start();
});
Events.on(ResetEvent.class, event -> stop());
Events.on(BuildinghangeEvent.class, event -> updateTile(event.tile));
}
/** Packs a tile into its internal representation. */
private int packTile(Tile tile){
return PathTile.get(tile.cost, (byte)tile.getTeamID(), !tile.solid() && tile.floor().drownTime <= 0f, !tile.solid() && tile.floor().isLiquid);
}
/** Starts or restarts the pathfinding thread. */
private void start(){
stop();
thread = Threads.daemon(this);
}
/** Stops the pathfinding thread. */
private void stop(){
if(thread != null){
thread.interrupt();
thread = null;
}
queue.clear();
}
/** Update a tile in the internal pathfinding grid.
* Causes a complete pathfinding reclaculation. Main thread only. */
public void updateTile(Tile tile){
if(net.client()) return;
int x = tile.x, y = tile.y;
tile.getLinkedTiles(t -> {
if(Structs.inBounds(t.x, t.y, tiles)){
tiles[t.x][t.y] = packTile(t);
}
});
//can't iterate through array so use the map, which should not lead to problems
for(Flowfield path : mainList){
if(path != null){
synchronized(path.targets){
path.targets.clear();
path.target.getPositions(path.team, path.targets);
}
}
}
queue.post(() -> {
for(Flowfield data : threadList){
updateTargets(data, x, y);
}
});
}
/** Thread implementation. */
@Override
public void run(){
while(true){
if(net.client()) return;
try{
if(state.isPlaying()){
queue.run();
//total update time no longer than maxUpdate
for(Flowfield data : threadList){
updateFrontier(data, maxUpdate / threadList.size);
//remove flowfields that have 'timed out' so they can be garbage collected and no longer waste space
if(data.target.refreshRate() > 0 && Time.timeSinceMillis(data.lastUpdateTime) > fieldTimeout){
//make sure it doesn't get removed twice
data.lastUpdateTime = Time.millis();
Team team = data.team;
Core.app.post(() -> {
//remove its used state
if(fieldMap[team.id] != null){
fieldMap[team.id].remove(data.target);
fieldMapUsed[team.id].remove(data.target);
}
//remove from main thread list
mainList.remove(data);
});
queue.post(() -> {
//remove from this thread list with a delay
threadList.remove(data);
});
}
}
}
try{
Thread.sleep(updateInterval);
}catch(InterruptedException e){
//stop looping when interrupted externally
return;
}
}catch(Throwable e){
e.printStackTrace();
}
}
}
public @Nullable Tile getTargetTile(Tile tile, Team team, Position target){
return getTargetTile(tile, team, getTarget(target));
}
/** Gets next tile to travel to. Main thread only. */
public @Nullable Tile getTargetTile(Tile tile, Team team, PathTarget target){
if(tile == null) return null;
if(fieldMap[team.id] == null){
fieldMap[team.id] = new ObjectMap<>();
fieldMapUsed[team.id] = new ObjectSet<>();
}
Flowfield data = fieldMap[team.id].get(target);
if(data == null){
//if this combination is not found, create it on request
if(fieldMapUsed[team.id].add(target)){
//grab targets since this is run on main thread
IntSeq targets = target.getPositions(team, new IntSeq());
queue.post(() -> createPath(team, target, targets));
}
return tile;
}
//if refresh rate is positive, queue a refresh
if(target.refreshRate() > 0 && Time.timeSinceMillis(data.lastUpdateTime) > target.refreshRate()){
data.lastUpdateTime = Time.millis();
tmpArray.clear();
data.target.getPositions(data.team, tmpArray);
synchronized(data.targets){
//make sure the position actually changed
if(!(data.targets.size == 1 && tmpArray.size == 1 && data.targets.first() == tmpArray.first())){
data.targets.clear();
data.target.getPositions(data.team, data.targets);
//queue an update
queue.post(() -> updateTargets(data));
}
}
}
int[][] values = data.weights;
int value = values[tile.x][tile.y];
Tile current = null;
int tl = 0;
for(Point2 point : Geometry.d8){
int dx = tile.x + point.x, dy = tile.y + point.y;
Tile other = world.tile(dx, dy);
if(other == null) continue;
if(values[dx][dy] < value && (current == null || values[dx][dy] < tl) && !other.solid() && other.floor().drownTime <= 0 &&
!(point.x != 0 && point.y != 0 && (world.solid(tile.x + point.x, tile.y) || world.solid(tile.x, tile.y + point.y)))){ //diagonal corner trap
current = other;
tl = values[dx][dy];
}
}
if(current == null || tl == impassable) return tile;
return current;
}
private PathTarget getTarget(Position position){
return targetCache.get(position, () -> new PositionTarget(position));
}
/** @return whether a tile can be passed through by this team. Pathfinding thread only. */
private boolean passable(int x, int y, Team team){
int tile = tiles[x][y];
return PathTile.passable(tile) || (PathTile.team(tile) != team.id && PathTile.team(tile) != (int)Team.derelict.id);
}
/**
* Clears the frontier, increments the search and sets up all flow sources.
* This only occurs for active teams.
*/
private void updateTargets(Flowfield path, int x, int y){
if(!Structs.inBounds(x, y, path.weights)) return;
if(path.weights[x][y] == 0){
//this was a previous target
path.frontier.clear();
}else if(!path.frontier.isEmpty()){
//skip if this path is processing
return;
}
//assign impassability to the tile
if(!passable(x, y, path.team)){
path.weights[x][y] = impassable;
}
//clear frontier to prevent contamination
path.frontier.clear();
updateTargets(path);
}
/** Increments the search and sets up flow sources. Does not change the frontier. */
private void updateTargets(Flowfield path){
//increment search, but do not clear the frontier
path.search++;
synchronized(path.targets){
//add targets
for(int i = 0; i < path.targets.size; i++){
int pos = path.targets.get(i);
int tx = Point2.x(pos), ty = Point2.y(pos);
path.weights[tx][ty] = 0;
path.searches[tx][ty] = path.search;
path.frontier.addFirst(pos);
}
}
}
private void preloadPath(Team team, PathTarget target){
updateFrontier(createPath(team, target, target.getPositions(team, new IntSeq())), -1);
}
/**
* Created a new flowfield that aims to get to a certain target for a certain team.
* Pathfinding thread only.
*/
private Flowfield createPath(Team team, PathTarget target, IntSeq targets){
Flowfield path = new Flowfield(team, target, world.width(), world.height());
path.lastUpdateTime = Time.millis();
threadList.add(path);
//add to main thread's list of paths
Core.app.post(() -> {
mainList.add(path);
if(fieldMap[team.id] != null){
fieldMap[team.id].put(target, path);
}
});
//grab targets from passed array
synchronized(path.targets){
path.targets.clear();
path.targets.addAll(targets);
}
//fill with impassables by default
for(int x = 0; x < world.width(); x++){
for(int y = 0; y < world.height(); y++){
path.weights[x][y] = impassable;
}
}
//add targets
for(int i = 0; i < path.targets.size; i++){
int pos = path.targets.get(i);
path.weights[Point2.x(pos)][Point2.y(pos)] = 0;
path.frontier.addFirst(pos);
}
return path;
}
/** Update the frontier for a path. Pathfinding thread only. */
private void updateFrontier(Flowfield path, long nsToRun){
long start = Time.nanos();
while(path.frontier.size > 0 && (nsToRun < 0 || Time.timeSinceNanos(start) <= nsToRun)){
Tile tile = world.tile(path.frontier.removeLast());
if(tile == null || path.weights == null) return; //something went horribly wrong, bail
int cost = path.weights[tile.x][tile.y];
//pathfinding overflowed for some reason, time to bail. the next block update will handle this, hopefully
if(path.frontier.size >= world.width() * world.height()){
path.frontier.clear();
return;
}
if(cost != impassable){
for(Point2 point : Geometry.d4){
int dx = tile.x + point.x, dy = tile.y + point.y;
Tile other = world.tile(dx, dy);
if(other != null && (path.weights[dx][dy] > cost + other.cost || path.searches[dx][dy] < path.search) && passable(dx, dy, path.team)){
if(other.cost < 0) throw new IllegalArgumentException("Tile cost cannot be negative! " + other);
path.frontier.addFirst(Point2.pack(dx, dy));
path.weights[dx][dy] = cost + other.cost;
path.searches[dx][dy] = (short)path.search;
}
}
}
}
}
/** A path target defines a set of targets for a path. */
public enum FlagTarget implements PathTarget{
enemyCores((team, out) -> {
for(Tile other : indexer.getEnemy(team, BlockFlag.core)){
out.add(other.pos());
}
//spawn points are also enemies.
if(state.rules.waves && team == state.rules.defaultTeam){
for(Tile other : spawner.getSpawns()){
out.add(other.pos());
}
}
}),
rallyPoints((team, out) -> {
for(Tile other : indexer.getAllied(team, BlockFlag.rally)){
out.add(other.pos());
}
});
public static final FlagTarget[] all = values();
private final Cons2<Team, IntSeq> targeter;
FlagTarget(Cons2<Team, IntSeq> targeter){
this.targeter = targeter;
}
@Override
public IntSeq getPositions(Team team, IntSeq out){
targeter.get(team, out);
return out;
}
@Override
public int refreshRate(){
return 0;
}
}
public static class PositionTarget implements PathTarget{
public final Position position;
public PositionTarget(Position position){
this.position = position;
}
@Override
public IntSeq getPositions(Team team, IntSeq out){
out.add(Point2.pack(world.toTile(position.getX()), world.toTile(position.getY())));
return out;
}
@Override
public int refreshRate(){
return 900;
}
}
public interface PathTarget{
/** Gets targets to pathfind towards. This must run on the main thread. */
IntSeq getPositions(Team team, IntSeq out);
/** Refresh rate in milliseconds. Return any number <= 0 to disable. */
int refreshRate();
}
/** Data for a specific flow field to some set of destinations. */
static class Flowfield{
/** Team this path is for. */
final Team team;
/** Flag that is being targeted. */
final PathTarget target;
/** costs of getting to a specific tile */
final int[][] weights;
/** search IDs of each position - the highest, most recent search is prioritized and overwritten */
final int[][] searches;
/** search frontier, these are Pos objects */
final IntQueue frontier = new IntQueue();
/** all target positions; these positions have a cost of 0, and must be synchronized on! */
final IntSeq targets = new IntSeq();
/** current search ID */
int search = 1;
/** last updated time */
long lastUpdateTime;
Flowfield(Team team, PathTarget target, int width, int height){
this.team = team;
this.target = target;
this.weights = new int[width][height];
this.searches = new int[width][height];
this.frontier.ensureCapacity((width + height) * 3);
}
}
/** Holds a copy of tile data for a specific tile position. */
@Struct
class PathTileStruct{
//traversal cost
short cost;
//team of block, if applicable (0 by default)
byte team;
//whether it's viable to pass this block
boolean passable;
//whether it's viable to pass this block through water
boolean passableWater;
}
}