pages/kronos/docs/particles.md

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Particles

Particles are free-floating elements that can move and have many different behaviors. They can also interact with the mouse.

To make particles, use makeParticles(particle, amount). particle is a particle-defining object, with features as explained below. There is also makeShinies, which uses different defaults and creates stationary particles at a random location. There are also a few other useful things listed at the end.


const myParticle {
    image:"options_wheel.png",
    spread: 20,
    gravity: 2,
    time: 3,
    speed() { // Randomize speed a bit
        return (Math.random() + 1.2) * 8 
    },
    etc...
}

Features can be functions or constant. These features will be called when each particle is made, with an id argument, which is assigned based on which of the amount particles being spawned this is. All of these are optional, with a default value.

All distances are in pixels and angles are in degrees, with 0 being up and going clockwise.

  • time: The amount of time, in seconds, that the particle will last. Default is 3.

  • fadeOutTime: The amount of seconds that fading out at the end should take (part of the total lifetime). Default is 1.

  • fadeInTime: The amount of seconds that fading in should take (part of the total lifetime). Default is 0.

  • image: The image the particle should display. "" will display no image. Default is a generic particle.

  • text: Displays text on the particle. Can use basic HTML.

  • style: Lets you apply other CSS styling to the particle.

  • width, height: The dimensions of the particle. Default is 35 and 35.

  • color: Sets the color of the image to this color.

  • angle: The angle that the particle should face. Default is 0.

  • dir: The initial angle that the particles should move in, before spread is factored in. Default is whatever angle is.

  • spread: If there are several particles, they will be spread out by this many degrees, centered on dir. Default is 30.

  • rotation: The amount that the (visual) angle of the particle should change by. Default is 0.

  • speed: The starting speed of the particle. Default is 15.

  • gravity: The amount the particle should accelerate downwards. Default is 0.

  • x, y: The starting coordinates of the particle. Default is at the mouse position.

  • offset: How far from the start each particle should appear. Default is 10.

  • xVel, yVel: Set initially based on other properties, then used to update movement.

  • layer: When changing tabs, if leaving the layer tab, this particle will be erased.

  • You can add other features to particles, but you must impliment their effects yourself.

Function features: These stay as functions and are for more advanced things. They are optional.

  • update(): Called each tick. Lets you do more advanced visual and movement behaviors by changing other properties.
  • onClick(), onMouseOver(), onMouseLeave(): Called when the particle is interacted with.

Other useful things that are not features of the particle object:

  • setDir(particle, dir), setSpeed(particle, speed): Set the speed/direction on a particle.
  • clearParticles(check): Function to delete particles. With no check, it deletes all particles. Check is a function that takes a particle, and returns true if that particle should be deleted.
  • You can use Vue.delete(particles, this.id) to make a particle delete itself.
  • mouseX and mouseY are variables that track the mouse position.
  • sin(x), cos(x), tan(x): functions that do these operations, with x in degrees. (Instead of radians).
  • asin(x), acos(x), atan(x): functions that do these operations, with the returned value in degrees. (instead of radians).