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game.system.Particle = () => {
"use strict";
const particleSpawners = {};
const particleSpawner = ({colors, maxAmount, minAmount, minLife, maxLife, minRadius, maxRadius, maxSpeed, spawnFunction}) => {
return Array(randomInRange(minAmount, maxAmount)).fill(0).map(() => {
let particleSpec = {
x: Math.random(),
y: Math.random(),
dx: Math.random() * maxSpeed - maxSpeed / 2,
dy: Math.random() * maxSpeed - maxSpeed / 2,
radius: randomInRange(minRadius, maxRadius),
color: colors[randomInRange(0, colors.length-1)],
lifetime: randomInRange(minLife, maxLife),
elapsed: 0,
};
if (spawnFunction) {
particleSpec = {...particleSpec, ...spawnFunction(particleSpec)};
}
return particleSpec;
});
};
const update = (elapsedTime, entities, _changedIds) => {
for (let id in entities) {
const entity = entities[id];
if (entity.hasComponent("particles")) {
if (!particleSpawners[entity.id]) {
particleSpawners[entity.id] = particleSpawner(entity.components.particles.spec.spec);
entities[id].particleSprite = game.graphics.Sprite({
drawFunction: (elapsedTime, {x, y, width, height}, context) => {
let particleSpawner = particleSpawners[entity.id];
particleSpawner.map((particleSpec) => particleSpec.elapsed += elapsedTime);
particleSpawners[id] = particleSpawner.filter((particleSpec) => particleSpec.lifetime > particleSpec.elapsed);
particleSpawner = particleSpawners[id];
if (particleSpawner.length === 0) {
entities[id].removeComponent("alive");
}
particleSpawner.map((particleSpec) => {
const position = {x: (particleSpec.x * width) + x + particleSpec.dx * particleSpec.elapsed, y: (particleSpec.y * height) + y + particleSpec.dy * particleSpec.elapsed};
const fill = context.fillStyle;
context.fillStyle = particleSpec.color;
context.beginPath();
context.arc(position.x, position.y, particleSpec.radius, 0, 2 * Math.PI);
context.fill();
context.fillStyle = fill;
});
}
});
}
}
}
return new Set();
};
return { update };
};
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