oscillate

Modular script for making objects bob up and down, or similar effects. Note: 8.1 users will have to fix the usage of 'var'

Script oscillate

/* Calculates an oscillating value with the given parameters.

   oscillate(magnitude, period)
  
   magnitude - distance the value deviates from 0
   period - number of steps it takes to do a full positive and negative cycle

   Note: depends on the global variable "count" being incremented by 1 every step
  
*/

var magnitude = argument0
var period = argument1

return magnitude * sin((global.count mod period)/period*pi*2)

Create of some controller object (e.g. "world")

global.count = 0

Step of some controller object (e.g. "world")

global.count += 1

Example use: in some object's step event

// make the object bob up and down
// it goes 3 pixels up and down from its center position
// and it takes 100 steps to go both up and down
y = ystart + oscillate(3,100)