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import RAPIER from "./rapier.es.js";
const CLICK_IMPULSE_MULTIPLIER = 300_000;
const GRAVITY = { x: 0.0, y: 2000 };
const LINEAR_DAMPING = 0.5;
const OBJ_BASE_RADIUS = 30;
const OBJ_BASE_SIZE = { x: OBJ_BASE_RADIUS * 2, y: OBJ_BASE_RADIUS * 2 };
const OBJ_MASS = 100;
const SCORE_DECAY_CURVE_L = 1000;
const SCORE_DECAY_CURVE_K = 0.01;
const SCORE_DECAY_CURVE_X0 = 1000;
const SCORE_DECAY_FACTOR = 30;
const SCORE_INCREMENT = 150;
const STEP_MS = 33;
const TARGET_WIDTH_FACTOR = 0.05;
const VIEWPORT_SIZE = {
x: document.documentElement.clientWidth,
y: document.documentElement.clientHeight,
};
const WIDTH_JUMP_FACTOR = 5;
const objElement = document.querySelector("#throwable");
const queryParams = new URLSearchParams(window.location.search);
const image = queryParams.get("image");
if (image !== null) {
objElement.style.backgroundColor = "inherit";
objElement.style.backgroundImage = `url(${decodeURI(image)})`;
}
const scoreElement = document.querySelector("#score");
const highScoreElement = document.querySelector("#high-score");
RAPIER.init().then(() => {
let world = new RAPIER.World(GRAVITY);
const wallColliderDescs = {
x: RAPIER.ColliderDesc.cuboid(VIEWPORT_SIZE.x, 1).setRestitution(1),
y: RAPIER.ColliderDesc.cuboid(1, VIEWPORT_SIZE.y).setRestitution(1),
};
world.createCollider(wallColliderDescs.x);
world.createCollider(wallColliderDescs.x.setTranslation(0, VIEWPORT_SIZE.y));
world.createCollider(wallColliderDescs.y);
world.createCollider(wallColliderDescs.y.setTranslation(VIEWPORT_SIZE.x, 0));
let objRigidBodyDesc = RAPIER.RigidBodyDesc.dynamic()
.setTranslation(VIEWPORT_SIZE.x / 2, VIEWPORT_SIZE.y / 3)
.setLinearDamping(LINEAR_DAMPING)
.setCcdEnabled(true);
let obj = world.createRigidBody(objRigidBodyDesc);
let objColliderDesc = RAPIER.ColliderDesc.ball(OBJ_BASE_RADIUS)
.setMass(OBJ_MASS)
.setActiveEvents(RAPIER.ActiveEvents.COLLISION_EVENTS);
world.createCollider(objColliderDesc, obj);
const objSize = {
x: OBJ_BASE_SIZE.x,
y: OBJ_BASE_SIZE.y,
};
let objVelocityLastFrame = null;
let lastCollision = { handle1: null, handle2: null };
let score = 0;
let highScore = score;
let lastScoredAt = performance.now();
const eventQueue = new RAPIER.EventQueue(true);
let mainLoop = () => {
world.step(eventQueue);
eventQueue.drainCollisionEvents((handle1, handle2, started) => {
if (
started &&
(handle1 !== lastCollision.handle1 || handle2 !== lastCollision.handle2)
) {
score += SCORE_INCREMENT;
if (score > highScore) {
highScore = score;
}
lastScoredAt = performance.now();
}
lastCollision = { handle1: handle1, handle2: handle2 };
});
const score_gap = performance.now() - lastScoredAt;
const score_decay_coefficient =
SCORE_DECAY_CURVE_L -
SCORE_DECAY_CURVE_L /
(1 + Math.exp(-SCORE_DECAY_CURVE_K * (score - SCORE_DECAY_CURVE_X0)));
if (score_gap > score_decay_coefficient) {
score -= score / SCORE_DECAY_FACTOR;
score = Math.max(score, 0);
}
scoreElement.textContent = `${Math.round(score)}`;
highScoreElement.textContent = `${Math.round(highScore)}`;
const objPosition = obj.translation();
objElement.style.left = `${objPosition.x}px`;
objElement.style.top = `${objPosition.y}px`;
const objVelocity = obj.linvel();
if (objVelocityLastFrame !== null) {
// Just delta velocity across a frame, technically
const objAcceleration = {
x: objVelocity.x - objVelocityLastFrame.x,
y: objVelocity.y - objVelocityLastFrame.y,
};
let targetWidth =
OBJ_BASE_SIZE.x + TARGET_WIDTH_FACTOR * Math.abs(objAcceleration.y);
let targetHeight =
OBJ_BASE_SIZE.y + TARGET_WIDTH_FACTOR * Math.abs(objAcceleration.x);
objSize.x = objSize.x + (targetWidth - objSize.x) / WIDTH_JUMP_FACTOR;
objSize.y = objSize.y + (targetHeight - objSize.y) / WIDTH_JUMP_FACTOR;
}
objVelocityLastFrame = objVelocity;
objElement.style.width = `${objSize.x}px`;
objElement.style.height = `${objSize.y}px`;
setTimeout(mainLoop, STEP_MS);
};
document.addEventListener("click", (e) => {
const clickPosition = { x: e.clientX, y: e.clientY };
const objPosition = obj.translation();
const direction = {
x: clickPosition.x - objPosition.x,
y: clickPosition.y - objPosition.y,
};
const distance = Math.sqrt(direction.x ** 2 + direction.y ** 2);
obj.setLinvel({ x: 0, y: 0 });
if (distance > 0) {
obj.applyImpulse(
{
x: (direction.x * CLICK_IMPULSE_MULTIPLIER) / distance,
y: (direction.y * CLICK_IMPULSE_MULTIPLIER) / distance,
},
true,
);
}
});
mainLoop();
});
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