I am working on a game app using React native and Matter.js.
I am trying to implement a system that adds points every time a bullet hits a target.
In order to do this, I am trying to use collisionStart to detect the collision.
However, even though the bullet and target collide only once, the event seems to be triggered 41 times.
This is the code:
Matter.Events.on(engine, 'collisionStart', (event) => {
let pairs = event.pairs
for (const pair of pairs) {
if (pair.bodyA.label === 'bullet' && pair.bodyB.label === 'Worm') {
console.log("target hit");
}
}
})
In the end, I'm planning to replace console.log with something that adds points. At the current moment, one collision seems like it would trigger the add points 41 times, which is obviously not ideal.
Any ideas what is happening here and how I can get this to trigger only once for one collision?
Try next example. I take it from my own project [you need little adaptd from ts to js]:
Matter.Events.on(this.starter.getEngine(), "collisionStart", function (event) {
root.collisionCheck(event, true);
});
public collisionCheck(event, ground: boolean) {
const myInstance = this;
const pairs = event.pairs;
for (let i = 0, j = pairs.length; i !== j; ++i) {
const pair = pairs[i];
if (pair.activeContacts) {
if (pair.bodyA.label === "bullet" && pair.bodyB.label === "Worm") {
const collectitem = pair.bodyA;
this.playerDie(collectitem);
} else if (pair.bodyB.label === "bullet" && pair.bodyA.label === "Worm") {
const collectitem = pair.bodyB;
this.playerDie(collectitem);
}
// ....
}
}
}
public destroyBody = (destroyBody) => {
try {
Matter.Composite.remove(this.getWorld(), destroyBody);
} catch(err) {
console.log(err)
}
}
If you still have same problem , we can adapt also with flag PREVENT_DOUBLE_BY_1_SECOUND for example.