@dcl/ecs
Version:
Decentraland ECS
114 lines (113 loc) • 5.17 kB
JavaScript
import * as components from '../components';
import { EntityState } from '../engine/entity';
/**
* @internal
*/
export function createTriggerAreaEventsSystem(engine) {
const triggerAreaResultComponent = components.TriggerAreaResult(engine);
const entitiesMap = new Map();
function hasCallbacksMap(entity) {
return entitiesMap.has(entity) && entitiesMap.get(entity) !== undefined;
}
function addEntityCallback(entity, triggerType, callback) {
if (hasCallbacksMap(entity)) {
entitiesMap.get(entity).triggerCallbackMap.set(triggerType, callback);
}
else {
entitiesMap.set(entity, {
triggerCallbackMap: new Map([[triggerType, callback]]),
lastConsumedTimestamp: -1
});
}
}
function removeEntityCallback(entity, triggerType) {
if (!entitiesMap.has(entity) || !entitiesMap.get(entity).triggerCallbackMap.has(triggerType))
return;
const triggerCallbackMap = entitiesMap.get(entity).triggerCallbackMap;
triggerCallbackMap.delete(triggerType);
// Remove entity if no more trigger callbacks are registered
if (triggerCallbackMap.size === 0)
entitiesMap.delete(entity);
}
function onTriggerEnter(entity, cb) {
addEntityCallback(entity, 0 /* TriggerAreaEventType.TAET_ENTER */, cb);
}
function removeOnTriggerEnter(entity) {
removeEntityCallback(entity, 0 /* TriggerAreaEventType.TAET_ENTER */);
}
function onTriggerStay(entity, cb) {
addEntityCallback(entity, 1 /* TriggerAreaEventType.TAET_STAY */, cb);
}
function removeOnTriggerStay(entity) {
removeEntityCallback(entity, 1 /* TriggerAreaEventType.TAET_STAY */);
}
function onTriggerExit(entity, cb) {
addEntityCallback(entity, 2 /* TriggerAreaEventType.TAET_EXIT */, cb);
}
function removeOnTriggerExit(entity) {
removeEntityCallback(entity, 2 /* TriggerAreaEventType.TAET_EXIT */);
}
engine.addSystem(function TriggerAreaResultSystem() {
const garbageEntries = [];
for (const [entity, data] of entitiesMap) {
if (engine.getEntityState(entity) === EntityState.Removed) {
garbageEntries.push(entity);
continue;
}
const result = triggerAreaResultComponent.get(entity);
// The Explorer may be taking time before the result component is put
if (result.size === 0)
continue;
const values = Array.from(result.values());
// determine starting index for new values (more than one could be added between System updates)
// search backwards to find the anchor at lastConsumedTimestamp
let startIndex = 0;
if (data.lastConsumedTimestamp >= 0) {
const newestTimestamp = values[values.length - 1].timestamp;
// if nothing new, skip processing
if (newestTimestamp <= data.lastConsumedTimestamp) {
continue;
}
// Find index of value with the lastConsumedTimestamp
let i = values.length - 2;
while (i >= 0 && values[i].timestamp > data.lastConsumedTimestamp)
i--;
// Mark the following value index as the starting point to trigger all the new value callbacks
startIndex = i + 1;
}
if (startIndex >= values.length)
continue;
// Trigger callbacks for all the new values
for (let i = startIndex; i < values.length; i++) {
switch (values[i].eventType) {
case 0 /* TriggerAreaEventType.TAET_ENTER */:
if (!data.triggerCallbackMap.has(0 /* TriggerAreaEventType.TAET_ENTER */))
continue;
data.triggerCallbackMap.get(0 /* TriggerAreaEventType.TAET_ENTER */)(values[i]);
break;
case 1 /* TriggerAreaEventType.TAET_STAY */:
if (!data.triggerCallbackMap.has(1 /* TriggerAreaEventType.TAET_STAY */))
continue;
data.triggerCallbackMap.get(1 /* TriggerAreaEventType.TAET_STAY */)(values[i]);
break;
case 2 /* TriggerAreaEventType.TAET_EXIT */:
if (!data.triggerCallbackMap.has(2 /* TriggerAreaEventType.TAET_EXIT */))
continue;
data.triggerCallbackMap.get(2 /* TriggerAreaEventType.TAET_EXIT */)(values[i]);
break;
}
}
data.lastConsumedTimestamp = values[values.length - 1].timestamp;
}
// Clean up garbage entries
garbageEntries.forEach((garbageEntity) => entitiesMap.delete(garbageEntity));
});
return {
onTriggerEnter,
removeOnTriggerEnter,
onTriggerStay,
removeOnTriggerStay,
onTriggerExit,
removeOnTriggerExit
};
}