Shard: Auto-targeting | Project Avalon

Auto-targeting

Files

src[+]
- Excalibur[+]
  Component[+]
  BaseComponent.ts
  ChasesTargetComponent.ts
  HasTargetComponent.ts
  SearchesTargetComponent.ts
  Scene[+]
  AutoTargetingScene.ts
index.html
index.tsentry
package.json
sandbox.config.json
styles.css
tsconfig.json

import {AutoTargetingScene} from "@avalon/Excalibur/Scene/AutoTargetingScene";
import {Engine} from "excalibur";

const canvasElement = document.createElement('canvas');
document.body.appendChild(canvasElement);

const engine = new Engine({
    canvasElement,
    scenes: {
        example: new AutoTargetingScene(),
    }
});

engine
    .start('example')
    .then(() => console.log('✅ Engine started!'));

src/registry/Excalibur/Component/SearchesTargetComponent.ts

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import {BaseComponent} from @avalon/Excalibur/Component/BaseComponent;
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import {HasTargetComponent} from @avalon/Excalibur/Component/HasTargetComponent;
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import {Actor, PreUpdateEvent, TagQuery} from "excalibur";
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export class SearchesTargetComponent extends BaseComponent {
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    private readonly queryTags: string[];
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    private readonly maxDistance?: number;
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    private query!: TagQuery<string>;
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    private nextCheck: number = 0;
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    constructor({queryTags, maxDistance}: { queryTags: string[], maxDistance?: number }) {
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        super();
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        this.queryTags = queryTags;
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        this.maxDistance = maxDistance;
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        this.on('preupdate', this.onPreUpdate.bind(this));
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    }
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    onPreUpdate({engine, delta}: PreUpdateEvent): void {
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        const owner = this.owner;
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        if (!owner) {
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            return;
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        }
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        this.nextCheck -= delta;
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        if (owner.has(HasTargetComponent) && this.nextCheck > 0) {
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            return;
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        }
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        if (!this.query) {
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            this.query = engine.currentScene.world.queryTags(this.queryTags);
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        }
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        let minDistance: number = Infinity;
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        let closestTarget: Actor | undefined;
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        for (const target of this.query?.entities ?? []) {
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            if (!(target instanceof Actor)) {
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                continue;
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            }
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            const distance = owner.pos.distance(target.pos);
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            if (this.maxDistance && distance > this.maxDistance) {
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                continue;
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            }
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            if (distance >= minDistance) {
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                continue;
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            }
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            minDistance = distance;
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            closestTarget = target;
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        }
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        this.nextCheck = 1000;
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        if (!closestTarget || owner.get(HasTargetComponent)?.target === closestTarget) {
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            return;
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        }
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        owner.addComponent(new HasTargetComponent(closestTarget), true);
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    }
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}

@avalon/Excalibur/Component/SearchesTargetComponent.tsCopy