humus-old/common/combat/vulnerable.trait.js

import * as I from 'immutable';

import {Trait} from '@avocado/entity';
import {
  behaviorItemFromJSON,
  buildInvoke,
  buildTraversal,
  createContext,
} from '@avocado/behavior';
import {hasGraphics, TextNodeRenderer} from '@avocado/graphics';
import {Vector} from '@avocado/math';

import {DamagePacket} from './damage.packet';
import {DamageEmitter} from './emitter';

export class Vulnerable extends Trait {

  static defaultParams() {
    const emitDamage = buildInvoke(['entity', 'emitParticle'], [
      'damage',
      buildTraversal(['entity', 'position']),
      buildTraversal(['damage']),
    ]);
    const playDamagingSound = buildInvoke(['damage', 'from', 'playSound'], [
      buildTraversal(['damage', 'from', 'damagingSound']),
    ]);
    return {
      tookDamageActions: {
        type: 'actions',
        traversals: [
          emitDamage,
          playDamagingSound,
        ],
      },
      vulnerabilities: undefined,
    }
  }

  static type() {
    return 'vulnerable';
  }

  constructor(entity, params, state) {
    super(entity, params, state);
    this.damageId = 0;
    this.damages = [];
    this._hasAddedEmitter = false;
    this._hasAddedEmitterRenderer = false;
    this._isHydrating  = false;
    this._isInvulnerable = false;
    this.locks = new Map();
    const tookDamageActionsJSON = this.params.tookDamageActions;
    this._tookDamageActions = behaviorItemFromJSON(tookDamageActionsJSON);
    this.tookDamageActionsList = [];
  }

  destroy() {
    this.locks.clear();
    this.tookDamageActionsList = [];
  }

  hydrate() {
    this._isHydrating = true;
    this.addEmitter();
    this.addEmitterRenderer();
  }

  acceptDamage(damage) {
    const context = createContext();
    context.add('entity', this.entity);
    context.add('damage', damage);
    const Actions = this._tookDamageActions.constructor;
    const actions = new Actions();
    actions.clone(this._tookDamageActions);
    const tuple = {context, actions};
    this.tookDamageActionsList.push(tuple);
    actions.on('actionsFinished', () => {
      context.clear();
      const index = this.tookDamageActionsList.indexOf(tuple);
      this.tookDamageActionsList.splice(tuple);
    });
  }

  acceptPacket(packet) {
    if (packet instanceof DamagePacket) {
      const damages = packet.data.damages;
      for (let i = 0; i < damages.length; ++i) {
        const damage = damages[i];
        if (this.entity.is('listed') && this.entity.list) {
          damage.from = this.entity.list.findEntity(damage.from);
        }
        else {
          damage.from = undefined;
        }
        this.acceptDamage(damage);
      }
    }
  }

  addEmitter() {
    if (!this._isHydrating) {
      return;
    }
    if (this._hasAddedEmitter) {
      return;
    }
    if (!this.entity.is('emitter')) {
      return;
    }
    this.entity.addEmitter('damage', new DamageEmitter());
    this._hasAddedEmitter = true;
  }

  addEmitterRenderer() {
    if (!this._isHydrating) {
      return;
    }
    if (this._hasAddedEmitterRenderer) {
      return;
    }
    if (!this.entity.is('emitter')) {
      return;
    }
    if (!this.entity.is('staged') || !this.entity.stage) {
      return;
    }
    const renderer = new TextNodeRenderer('.damage', this.entity.stage);
    this.entity.addEmitterRenderer('damage', renderer);
    this._hasAddedEmitterRenderer = true;
  }

  get isInvulnerable() {
    return this._isInvulnerable;
  }

  set isInvulnerable(isInvulnerable) {
    this._isInvulnerable = isInvulnerable;
  }

  packetsForUpdate() {
    const packets = [];
    if (this.damages.length > 0) {
      packets.push(new DamagePacket({
        damages: this.damages,
      }, this.entity));
      this.damages = [];
    }
    return packets;
  }

  listeners() {
    return {

      dying: () => {
        this._isInvulnerable = true;
      },

      stageChanged: () => {
        this.addEmitterRenderer();
      },

      tookDamage: (damage) => {
        if (AVOCADO_SERVER) {
          this.damages.push(damage);
        }
      },

      traitsChanged: () => {
        this.addEmitter();
        this.addEmitterRenderer();
      },

    };
  }

  methods() {
    return {

      takeDamageFrom: (entity) => {
        const damageSpecs = entity.damageSpecs;
        for (let i = 0; i < damageSpecs.length; ++i) {
          const damageSpec = damageSpecs[i];
          let power = damageSpec.power;
          // Check if vulnerable to this affinity.
          if (this.params.vulnerabilities) {
            if (damageSpec.affinity in this.params.vulnerabilities) {
              power *= this.params.vulnerabilities[damageSpec.affinity];
            }
          }
          if (this.locks.has(damageSpec)) {
            continue;
          }
          this.locks.set(damageSpec, damageSpec.lock);
          // Give any knockback.
          if (damageSpec.knockback) {
            if (
              this.entity.is('mobile')
              && this.entity.is('positioned')
              && entity.is('positioned')
            ) {
              const difference = Vector.sub(
                this.entity.position,
                entity.position,
              );
              const unit = Vector.normalize(difference)
              const knockback = Vector.scale(unit, damageSpec.knockback);
              this.entity.applyMovement(knockback);
            }
          }
          const variance = Math.random() * damageSpec.variance * 2 - damageSpec.variance;
          const difference = power * variance;
          // Account for variance past 0, so track if it's damage or not.
          let amount = Math.round(power + difference);
          let isDamage;
          if (power < 0) {
            isDamage = false;
            if (amount > 0) {
              amount = 0;
            }
          }
          else {
            isDamage = true;
            if (amount < 0) {
              amount = 0;
            }
          }
          amount = Math.abs(amount);
          const damage = {
            id: this.damageId++,
            isDamage,
            amount,
            damageSpec,
            from: entity.numericUid,
          };
          this.entity.emit('tookDamage', damage);
        }
      },

    };
  }

  tick(elapsed) {
    if (AVOCADO_CLIENT) {
      for (let i = 0; i < this.tookDamageActionsList.length; ++i) {
        const {context, actions} = this.tookDamageActionsList[i];
        actions.tick(context, elapsed);
      }
    }
    if (AVOCADO_SERVER) {
      const keyIterator = this.locks.keys();
      for (
        let thisKey = keyIterator.next();
        thisKey.done !== true;
        thisKey = keyIterator.next()
      ) {
        const {value: key} = thisKey;
        const remaining = this.locks.get(key) - elapsed;
        if (remaining <= 0) {
          this.locks.delete(key);
        }
        else {
          this.locks.set(key, remaining);
        }
      }
    }
  }

}