get rid of pships

lots of things rely on exactly one primary ship now, so this was just
overhead and wasted tokens / cspace.

vacuum_gambit.p8

@@ -169,8 +169,6 @@ function wipe_game()
  xpwhoosh = nil
  primary_ship = player.new()
  init_hpcols()
- pships = linked_list.new()
- pships:push_back(primary_ship)
  eships = linked_list.new()
  pbullets = linked_list.new()
  ebullets = linked_list.new()
@@ -208,7 +206,8 @@ function ones(n)
 end
 
 function updategame()
- if (primary_ship.xp >= primary_ship.xptarget) and (gframe - primary_ship.last_xp_frame > 0x0.000f) and (not primary_ship.dead) then
+ local ps = primary_ship
+ if (ps.xp >= ps.xptarget) and (gframe - ps.last_xp_frame > 0x0.000f) and (not ps.dead) then
   mode = rearm_mode.new()
   return _update60()
  end
@@ -238,36 +237,24 @@ function updategame()
  end
  events:vore(new_events)
  events:strip(call_move)
- for _, lst in ipairs{intangibles_bg, pships, eships, pbullets, ebullets} do
+ for _, lst in ipairs{intangibles_bg, eships, pbullets, ebullets} do
   lst:strip(call_move)
  end
 
- pships:strip(
-  function(ps)
-   local pbox, pded = hurtbox(ps), false
-   eships:strip(
-    function(es)
-     if (not collides(pbox, hurtbox(es))) return
-     pded = pded or ps:hitship(es)
+ if not ps.dead then
+  ps:move()
+  local pbox = hurtbox(ps)
+  eships:strip(function(es)
+   if(not collides(pbox, hurtbox(es))) return
+   ps:hitship(es)
    return es:hitship(ps)
-    end
-   )
-   return pded
-  end
- )
- pships:strip(
-  function(ps)
-   local pbox, pded = hurtbox(ps), false
-   ebullets:strip(
-    function(eb)
+  end)
+  ebullets:strip(function(eb)
    if (not collides(pbox, hurtbox(eb))) return
-     pded = pded or ps:hitbullet(eb)
+   ps:hitbullet(eb)
    return eb:hitship(ps)
+  end)
  end
-   )
-   return pded
-  end
- )
 
 	-- many bullets and many enemy ships;
 	-- use bucket collider for efficiency
@@ -302,9 +289,9 @@ function updategame()
 	if waves_complete == 32767 and not eships.next and not ebullets.next and not events.next then
 	  game_state = win
 	end
-	if (not pships.next) game_state = lose
+	if (ps.dead) game_state = lose
 
- if primary_ship.xp >= primary_ship.xptarget then
+ if ps.xp >= ps.xptarget then
   if not xpwhoosh then
    xpwhoosh = 0
   else
@@ -393,8 +380,8 @@ end
 function drawgame()
  clip(0,0,112,128)
  rectfill(0,0,112,128,0)
- for slist in all{intangibles_bg, pbullets, pships, eships, ebullets, intangibles_fg} do
-  slist:draw()
+ for drawable in all{intangibles_bg, pbullets, primary_ship, eships, ebullets, intangibles_fg} do
+  drawable:draw()
  end
  clip(0,0,128,128)
  drawhud()
@@ -624,6 +611,7 @@ function ship_m:move()
 end
 
 function ship_m:draw()
+ if (self.dead) return
  if(self.fx_pal) pal(self.fx_pal)
  spr(self.sprite, self.x, self.y, self.size, self.size)
  pal()