refactor spark logic. this loses tokens; may need to revisit

updatedshmup.p8

@@ -1789,29 +1789,33 @@ function boom(x,y,boominess,is_boss)
  return
 end
 
+spark_particle={}
+
+function spark_particle:move()
+ if (rnd(4) < 1) self.sidx += 1
+ if (self.sidx > #self.sprs) return true
+ self.x += self.dx
+ self.y += self.dy
+ self.dx -= mid(0.05,-0.05, self.dx)
+ self.dy -= mid(0.05,-0.05, self.dy)
+end
+function spark_particle:draw()
+ pset(self.x,self.y,self.sprs[self.sidx])
+end
+mknew(spark_particle)
+
 function spark(sprs, x, y, butts, thrust, odds, fg)
  if (sprs==nil or flr(rnd(odds)) ~= 0) return
  thrust *= 2.5
  local target = fg and intangibles_fg or intangibles_bg
- target:push_back{
+ target:push_back(spark_particle.new{
   x = x + rnd(4) - 2,
   y = y + rnd(4) - 2,
   sprs = sprs,
   sidx = 1,
   dx = (butts[0] - butts[1]) * thrust + rnd(2) - 1,
   dy = (butts[2] - butts[3]) * thrust + rnd(2) - 1,
-  draw = function(self)
-   pset(self.x, self.y, self.sprs[self.sidx])
-  end,
-  move = function(self)
-   if (rnd(4) < 1) self.sidx += 1
-   if (self.sidx > #self.sprs) return true
-   self.x += self.dx
-   self.y += self.dy
-   self.dx -= mid(0.05,-0.05, self.dx)
-   self.dy -= mid(0.05,-0.05, self.dy)
-  end
- }
+ })
 end
 -->8
 -- powerups