func (p *Particle) ReverseY() {
	p.Direction[1] = -p.Direction[1]
}
ReverseY makes particles go the other way
package particles
type Config struct {
	Speed  float64
	Area   float64
	Size   float64
	Color  string
	Bounds bool
	Bounce bool
	Move   bool
}
var DefaultConfig = Config{2.0, 80.0, 1.8, "#ccccFF", true, true, true}
type Particles []*Particle
type Particle struct {
	Config
	ID        int
	Position  Vector
	Direction Vector
}
func NewParticle(id int, config Config) *Particle {
	return &Particle{
		ID:     id,
		Config: config,
		Direction: Vector{
			randf(-100, 100) / 100.0,
			randf(-100, 100) / 100.0,
		},
	}
}
func (p *Particle) RandomizePosition(width, height int) {
	p.Position = Vector{
		randf(0, width),
		randf(0, height),
	}
}
func (p *Particle) ReverseX() {
	p.Direction[0] = -p.Direction[0]
}