prosperon/scripts/particle.js
2024-10-29 12:41:17 -05:00

139 lines
2.9 KiB
JavaScript

var emitter = {};
emitter.life = 10;
emitter.scale = 1;
emitter.grow_for = 0;
emitter.spawn_timer = 0;
emitter.pps = 0;
emitter.color = Color.white;
var ssbo;
emitter.kill = function () {
emitters.remove(this);
};
var std_step = function (p) {
if (p.time < this.grow_for) {
var s = Math.lerp(0, this.scale, p.time / this.grow_for);
p.transform.scale = s;
} else if (p.time > p.life - this.shrink_for) {
var s = Math.lerp(0, this.scale, (p.life - p.time) / this.shrink_for);
p.transform.scale = s;
} else p.transform.scale = [this.scale, this.scale, this.scale];
};
emitter.step_hook = std_step;
emitter.spawn = function (t) {
t ??= this.transform;
var par = this.dead.shift();
if (par) {
par.transform.scale = this.scale;
this.particles.push(par);
par.time = 0;
this.spawn_hook?.(par);
par.life = this.life;
return;
}
par = {
transform: os.make_transform(),
life: this.life,
time: 0,
color: this.color,
};
par.transform.scale = this.scale;
this.particles.push(par);
this.spawn_hook(par);
};
emitter.step = function (dt) {
// update spawning particles
if (this.on && this.pps > 0) {
this.spawn_timer += dt;
var pp = 1 / this.pps;
while (this.spawn_timer > pp) {
this.spawn_timer -= pp;
this.spawn();
}
}
// update all particles
for (var p of this.particles) {
p.time += dt;
this.step_hook?.(p);
if (this.kill_hook?.(p) || p.time >= p.life) {
this.die_hook?.(p);
this.dead.push(p);
this.particles.remove(p);
}
}
};
emitter.burst = function (count, t) {
for (var i = 0; i < count; i++) this.spawn(t);
};
var emitters = [];
var make_emitter = function () {
var e = Object.create(emitter);
e.ssbo = render.make_textssbo();
e.shape = shape.centered_quad;
e.shader = "shaders/baseparticle.cg";
e.particles = [];
e.dead = [];
emitters.push(e);
return e;
};
function update_emitters(dt) {
for (var e of emitters) e.step(dt);
}
var arr = [];
function draw_emitters() {
return;
ssbo ??= render.make_textssbo();
render.use_shader("shaders/baseparticle.cg");
var buckets = {};
var base = 0;
for (var e of emitters) {
var bucket = buckets[e.diffuse.path];
if (!bucket)
buckets[e.diffuse.path] = [e];
else
bucket.push(e);
}
for (var path in buckets) {
arr.length = 0;
var bucket = buckets[path];
bucket[0].baseinstance = base;
render.use_mat(bucket[0]);
for (var e of bucket) {
if (e.particles.length === 0) continue;
for (var p of e.particles) arr.push(p);
}
render.make_particle_ssbo(arr, ssbo);
render.draw(bucket[0].shape, ssbo, arr.length);
base += arr.length;
}
}
function stat_emitters()
{
var stat = {};
stat.emitters = emitters.length;
var particles = 0;
for (var e of emitters) particles += e.particles.length;
stat.particles = particles;
return stat;
}
return { make_emitter, update_emitters, draw_emitters, stat_emitters };