animation.lua

-- Animation function that supports
-- animation speed, looping (or not looping),
-- stopping on a specific frame, flipping
-- horizontal and/or vertical, and playing
-- in reverse

-- Contributors: Scathe (@clowerweb)

function anim(a,anim,offx,offy)
 if(anim.loop!=false) then
  anim.loop=true
 end

 anim.step=anim.step or 0

 local sta=anim.start
 local cur=anim.current or 0
 local stp=anim.step
 local spd=anim.speed
 local flx=anim.flipx
 local fly=anim.flipy
 local rst=anim.reset or 0
 local lop=anim.loop
 local rev=anim.reverse or false

 anim.step+=1
 stp=anim.step
 if(not rev) then
  if(stp%flr(30/spd)==0) cur+=1
  if(cur==anim.frames) then
   if(lop) then cur=0
   else cur-=1 end
  end
 else
  if(stp%flr(30/spd)==0) cur-=1
  if(cur<0) cur=0
 end

 anim.current=cur

 if(not offx) offx=0
 if(not offy) offy=0

 spr(sta+cur,a.x+offx,a.y+offy,
     1,1,flx,fly)
end -- anim