README.md

dr-particles

Small library and example code to create particle emitters in DragonRuby

Demo

example.mp4

The emitters used to create the effects above can be found in example_emitters.rb

Installation

Preferred install is via DragonRuby builtin download_stb_rb

First, download the lib using the above method, in the DragonRuby Console:

$gtk.download_stb_rb "https://github.com/owenbutler/dr-particles/blob/main/app/particles.rb"

By default, this will download the lib to owenbutler/dr-particles/particles.rb

Include the following in your main.rb:

require 'owenbutler/dr-particles/particles.rb'

For more control over where the lib is downloaded, see the docs for download_stb_rb

Usage

Minimal example:

require 'owenbutler/dr-particles/particles.rb'

$particles = []
$emitters = [
  {
    num: 6, freq: 1,
    x: 650, y: 120, w: 16, h: 16,
    grow_factor: 1.002,
    path: 'sprites/circle/white.png',
    xv_min: -5.7, xv_max: 5.7,
    yv_min: 8, yv_max: 15.0,
    grav: true, grav_x: 0.0, grav_y: -0.201,
    time: 100,
    r: 255, g: 50, b: 70,
    a: 255, blendmode_enum: 2,
    fade: true, fade_start: 255, fade_end: 0, fade_ease: :quad,
  },
]

def tick args

  args.outputs.background_color = [0, 0, 0]

  particles_tick($emitters, $particles, args)
end