5、粒子云的创建、控制与可视化

粒子云的创建、控制与可视化

1. 控制多个粒子

在处理多个粒子时，我们可以通过修改 Particle 类中的 move 函数来限制粒子在画布内移动。以下是修改后的 move 函数：

public void move() {
    // calculate the particle's distance from the center
    if (dist(this.x, this.y, 0, 0) > 250) {
        // create position and new random target position
        PVector position = new PVector(this.x, this.y);
        PVector target = new PVector(random(-250, 250), random(-250, 250));
        // calculate direction vector between
        // current and target position
        PVector direction = PVector.sub(target, position);
        // divide direction by 600 to make the steps small
        direction.div(600);
        // set the new direction for the particle