initial commit

resources/js/engine/ParticleSystem.js

@@ -0,0 +1,109 @@
+import { Vector2D } from './Vector2D.js';
+
+const MAX_PARTICLES = 450;
+
+export class ParticleSystem {
+  constructor() {
+    this.particles = [];
+  }
+
+  burst(
+    x,
+    y,
+    {
+      count = 12,
+      speed = 150,
+      direction = 0,
+      spread = Math.PI * 2,
+      life = 0.4,
+      size = 4,
+      color = [1, 1, 1, 1],
+      gravity = 0,
+      drag = 0,
+      shape = 'square',
+      additive = false,
+      endSize = null,
+      spin = 0,
+    } = {},
+  ) {
+    for (let i = 0; i < count; i++) {
+      if (this.particles.length >= MAX_PARTICLES) return;
+
+      const angle = direction + (Math.random() - 0.5) * spread;
+      const magnitude = speed * (0.4 + Math.random() * 0.8);
+      const velocity = new Vector2D(Math.cos(angle), Math.sin(angle)).mulS(magnitude);
+      const lifetime = life * (0.6 + Math.random() * 0.6);
+      const startSize = size * (0.6 + Math.random() * 0.8);
+
+      this.particles.push({
+        pos: new Vector2D(x, y),
+        velocity,
+        gravity,
+        drag,
+        life: lifetime,
+        maxLife: lifetime,
+        size: startSize,
+        endSize: endSize === null ? startSize * 0.15 : endSize * (0.6 + Math.random() * 0.8),
+        color: [...color],
+        shape,
+        additive,
+        angle: Math.random() * Math.PI * 2,
+        spin: (Math.random() - 0.5) * (spin * 2),
+      });
+    }
+  }
+
+  update(dt) {
+    const { particles } = this;
+    for (let i = particles.length - 1; i >= 0; i--) {
+      const particle = particles[i];
+      particle.pos = particle.velocity.mulS(dt).addV(particle.pos);
+      particle.velocity.y += particle.gravity * dt;
+      if (particle.drag > 0) {
+        particle.velocity = particle.velocity.mulS(Math.max(0, 1 - particle.drag * dt));
+      }
+      particle.angle += particle.spin * dt;
+      particle.life -= dt;
+      if (particle.life <= 0) {
+        particles.splice(i, 1);
+      }
+    }
+  }
+
+  draw(renderer) {
+    const additive = this.particles.filter((particle) => particle.additive);
+    const normal = this.particles.filter((particle) => !particle.additive);
+
+    if (additive.length > 0) renderer.setBlendMode('additive');
+    for (const particle of additive) this._drawParticle(renderer, particle);
+    if (additive.length > 0) renderer.setBlendMode('normal');
+
+    for (const particle of normal) this._drawParticle(renderer, particle);
+  }
+
+  _drawParticle(renderer, particle) {
+    const alpha = Math.max(0, particle.life / particle.maxLife);
+    const progress = 1 - alpha;
+    const size = particle.size + (particle.endSize - particle.size) * progress;
+    const color = [
+      particle.color[0],
+      particle.color[1],
+      particle.color[2],
+      particle.color[3] * alpha,
+    ];
+    const texture = particle.shape === 'glow' ? renderer.glowTexture : renderer.whiteTexture;
+    renderer.drawTexture(
+      texture,
+      particle.pos.x - size / 2,
+      particle.pos.y - size / 2,
+      size,
+      size,
+      color,
+      particle.angle,
+    );
+  }
+
+  clear() {
+    this.particles.length = 0;
+  }
+}