During — Preposition Programming

Fig. 1 Overlapping process — particles emit throughout the journey

Try it — drag, click, or tap inside the figure.

Open in p5 Web Editor Fork and experiment with this sketch

Concept

DURING means throughout the span of another process. Run secondary logic on each frame while the primary action is still underway.

Translation strategy

Ways to express during in code:

Overlapping activity: Emit or update while a flag is true
Primary process: A journey or timer that must stay active
Frame timing: Use frameCount or modulo for emission rate

Key p5.js methods

Key methods

Timing
• frameCount — periodic emission
• random() — vary particle velocity

Motion
• atan2(), cos(), sin() — traveler direction

Pointer input
• mousePressed() — start motion or set a target
• mouseX, mouseY — click position

Code pattern

Code pattern

1. Define the journey
let traveler = { x: 50, y: 150, targetX: 350, targetY: 150, moving: false };

2. Move while active
if (traveler.moving) { /* update x, y toward target */ }

3. Emit during movement
if (traveler.moving && frameCount % 8 === 0) {
particles.push({ x: traveler.x, y: traveler.y, vx, vy });
}

4. Update particles each frame
particle.x += particle.vx; particle.life -= 0.01;