try using a path for a skirmisher

slightly stabilized but the length operator does not work in the presence of Lua Crimes like this so it needs more work

vacuum_gambit.p8

@@ -194,7 +194,9 @@ function updategame()
   interlude -= 1
  else
   current_wave = flotilla.new()
-  current_wave:load(rnd() > 0.5 and 7 or 0, 0, min(ones(waves_complete)\2, 4))
+  --current_wave:load(rnd() > 0.5 and 7 or 0, 0, min(ones(waves_complete)\2, 4))
+  current_wave:load(0, 0, min(ones(waves_complete)\2, 4))
+  current_wave:update()
  end
  events = filtermoved(events)
  appendmove(events, new_events)
@@ -662,7 +664,7 @@ function destination:target_from(fx, fy)
  if (xf > 0) rx = lerp(rx, 112, xf)
  if (yf < 0) ry = lerp(ry, 0, -yf)
  if (yf > 0) ry = lerp(ry, 128, yf)
- return rx, ry
+ return rx, ry, self.accel_frac
 end
 
 segment = mknew{
@@ -686,22 +688,35 @@ segment = mknew{
  --  figure out approach/depart
  -- [1..n]: destinations
  init = function(x)
-  x.remain = x.limit
+  x.init = segment.reset
+  mknew(x)
+  if not x.mirror then
+   local mirrored = {mirror=x, init=segment.reset}
+   for i, v in ipairs(x) do
+    mirrored[i] = destination.new{
+     anchor_frac=v.anchor_frac,
+     accel_frac=v.accel_frac,
+     x_off_frac=-v.x_off_frac,
+     y_off_frac=v.y_off_frac,
+    }
+   end
+   x.mirror = mknew(x.new(mirrored))
+  end
  end
 }
 
 function segment:reset()
  self.current_idx = 1
  self.remain = self.limit
- self.prev_x = nil
- self.prev_y = nil
+ self.prev_x = false
+ self.prev_y = false
  self.was_approaching = false
 end
 
 function segment:target_from(fx, fy)
- local rx, ry = self[self.current_idx]:target_from(fx, fy)
+ local rx, ry, af = self[self.current_idx]:target_from(fx, fy)
  self.dest_x, self.dest_y = rx, ry
- return rx, ry
+ return rx, ry, af
 end
 
 function segment:update(x, y)
@@ -745,12 +760,29 @@ end
 
 path = mknew {
  loop_idx = 1,
- current_idx = 1,
  -- [1..n]: destinations
+ init=function(x)
+  if not x.mirror then
+   local mirrored = {
+    mirror = x,
+    loop_idx = x.loop_idx,
+   }
+   for i, v in ipairs(x) do
+    mirrored[i]=v.mirror
+   end
+   x.mirror = path.new(mirrored)
+  end
+  x.init = function(y)
+   for i, v in ipairs(x) do
+    y[i]=v.new{}
+   end
+   y:reset()
+  end
+  mknew(x)
+ end,
 }
 
 function path:reset()
- self.loop_idx = 1
  self.current_idx = 1
 end
 
@@ -1457,13 +1489,26 @@ ship_f = mknew(ship_m.new{
  act = function(self)
   local wx,wy=self.want_x,self.want_y
   self.xmin,self.xmax,self.ymin,self.ymax = wx,wx,wy,wy
-  return 0,0,false,false
+  return 0,0
  end,
  init = function(self)
   if (self.gun_proto) self.main_gun = self.gun_proto.new()
+  if (self.path) self.path = self.path.new()
  end
 })
 
+diamond_loop = segment.new{
+ destination.new{
+  x_off_frac=0.25
+ }, destination.new{
+  y_off_frac=0.25
+ }, destination.new {
+  x_off_frac = -0.25
+ }, destination.new {
+  y_off_frac = -0.25
+ },
+}
+
 ship_mook = mknew(ship_f.new{
  sprite=103
 })
@@ -1485,12 +1530,33 @@ ship_skirmisher = mknew(ship_f.new{
  fire_off_y = 7,
  xmin = -8,
  xmax = 112,
+ path = diamond_loop,
 })
 
 function ship_skirmisher:reset_bounds()
  self.xmin, self.xmax, self.ymin, self.ymax = -8, 112, 0, 120
 end
 
+function ship_skirmisher:act()
+ local tx, ty, af = self.path:target_from(self.want_x+4, self.want_y+4)
+ tx -= 4
+ ty -= 4
+ if af <= 0 then
+  self.xmin, self.xmax, self.ymin, self.ymax = tx,tx,ty,ty
+  return 0,0
+ end
+ self:reset_bounds()
+ local ax, ay, th = tx - self.x, ty - self.y, self.thrust*af
+ local ma = max(abs(ax), abs(ay))
+ return ax*th/ma, ay*th/ma
+end
+
+function ship_skirmisher:move()
+ if (not ship_f.move(self)) return
+ if (not self.path:update(self.x+4, self.y+4)) self.path:reset()
+ return true
+end
+
 function rnd_spawn_loc()
  local x,y = flr(rnd(304)), flr(rnd(32))
  if (x<184) return x-40,-y-8