Programming math issue

Question

I want to program an explosion in java(not really relevant)

 

My particle class updates the integer time 60 * a second and needs to change color based on which stage the explosion is in(7 stages)

I can't figure out how to set/advance the stage based on :

What percentage of the maximum lifetime of the particle has passed comparing with the variable time

 

I guess what I'm looking for is an equation or something to accomplish this

Any advice would be greatly appreciated ,)

Answer 1

Yes, you need some sort of exponential growth/decay function

some physical sample data will be helpful, especially if they

clearly demonstrate the 7 levels you are referring to...

also perhaps a color scheme for each level