Improve gameplay

backend/src/players/player-base.ts

@@ -1,9 +1,17 @@
 import { vec2 } from 'gl-matrix';
-import { CommandReceiver, Circle, PlayerInformation, CharacterTeam } from 'shared';
+import {
+  CommandReceiver,
+  Circle,
+  PlayerInformation,
+  CharacterTeam,
+  Random,
+  settings,
+} from 'shared';
 import { PhysicalContainer } from '../physics/containers/physical-container';
 import { getBoundingBoxOfCircle } from '../physics/functions/get-bounding-box-of-circle';
 import { isCircleIntersecting } from '../physics/functions/is-circle-intersecting';
 import { CharacterPhysical } from '../objects/character-physical';
+import { PlanetPhysical } from '../objects/planet-physical';
 import { PlayerContainer } from './player-container';
 
 export abstract class PlayerBase extends CommandReceiver {
@@ -22,14 +30,14 @@ export abstract class PlayerBase extends CommandReceiver {
     super();
   }
 
-  protected createCharacter(preferredCenter: vec2) {
+  protected createCharacter() {
     this.character = new CharacterPhysical(
       this.playerInfo.name.slice(0, 20),
       this.sumKills,
       this.sumDeaths,
       this.team,
       this.objectContainer,
-      this.findEmptyPositionForPlayer(preferredCenter),
+      this.findEmptyPositionForPlayer(this.findSpawnCenter()),
     );
 
     this.objectContainer.addObject(this.character);
@@ -37,14 +45,37 @@ export abstract class PlayerBase extends CommandReceiver {
 
   public abstract step(deltaTimeInSeconds: number): void;
 
-  protected findEmptyPositionForPlayer(preferredCenter: vec2): vec2 {
-    if (!preferredCenter) {
-      preferredCenter = vec2.create();
+  private findSpawnCenter(): vec2 {
+    const planets = this.objectContainer
+      .findIntersecting(
+        getBoundingBoxOfCircle(new Circle(vec2.create(), settings.worldRadius * 2)),
+      )
+      .filter((o): o is PlanetPhysical => o instanceof PlanetPhysical);
+
+    const friendly = planets.filter((p) => p.team === this.team);
+    const neutral = planets.filter((p) => p.team === CharacterTeam.neutral);
+    const candidates = friendly.length ? friendly : neutral.length ? neutral : planets;
+    if (candidates.length === 0) {
+      return vec2.create();
     }
 
+    const isContested = (planet: PlanetPhysical) =>
+      this.playerContainer.players.some(
+        (p) =>
+          p.team !== this.team &&
+          p.character?.isAlive &&
+          vec2.distance(p.center, planet.center) < settings.spawnSafetyDistance,
+      );
+    const safe = candidates.filter((p) => !isContested(p));
+
+    // candidates is non-empty here, so choose() always returns a planet.
+    return vec2.clone(Random.choose(safe.length ? safe : candidates)!.center);
+  }
+
+  protected findEmptyPositionForPlayer(preferredCenter: vec2): vec2 {
     let rotation = 0;
     let radius = 0;
-    for (;;) {
+    for (; ;) {
       const playerPosition = vec2.fromValues(
         radius * Math.cos(rotation) + preferredCenter.x,
         radius * Math.sin(rotation) + preferredCenter.y,