bullet microoptimization and velocity fix

vacuum_gambit.p8

@@ -823,10 +823,13 @@ function bullet_base:hitship(_)
 end
 
 function bullet_base:move()
- self.x += self.dx
- self.y += self.dy
- if (self.f) self.f -= 1
- return (self.y > 130) or (self.y < -self.height*8) or (self.f and self.f < 0) or (self.x > 128) or (self.x < -self.width*8)
+ local x,y,f = self.x + self.dx, self.y+self.dy,self.f
+ self.x,self.y=x,y
+ if f then
+  self.f = f-1
+  if (f <= 0) return true
+ end
+ return (y> 130) or (y < -(self.height<<3)) or (x > 128) or (x < -(self.width<<3))
 end
 
 function bullet_base:draw()
@@ -868,25 +871,20 @@ function gun_base:actually_shoot(x, y)
  self.shot_idx = idx
  shots = shots[idx]
  for s in all(shots) do
-  local a,xo,v = unpack(s)
-  v = v or veloc
-  xo = xo or 0
+  local a,xo,v = s[1]+aim, s[2] or 0, s[3] or veloc
   -- reverse x-offset for negative base angle
   if (aim < 0) xo = -xo
-  a += aim
   -- todo: switch munition
   --  depending on angle
   --  (allows for non-round
   --   sprites and hitboxes on
   --   shots from guns with
   --   widely varying angles)
-  local m = munition.new{}
-  -- todo: automatically make
-  -- high velocity shots do
-  -- multiple collision checks
-  m.dy = sin(a) * veloc
-  m.dx = cos(a) * veloc
-  m:spawn_at(x+(xo or 0), y)
+  local m = munition.new{
+   dx=sin(a)*v,
+   dy=cos(a)*v
+  }
+  m:spawn_at(x+xo, y)
  end
 end