paths sort of work but not really

figure out why they do not show the expected patterns

vacuum_gambit.p8

@@ -686,21 +686,21 @@ segment = mknew{
  -- dest_x, dest_y: stored
  --  current destination to
  --  figure out approach/depart
- -- [1..n]: destinations
+ -- dests[1..n]: destinations
  init = function(x)
   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{
+   local mdests = {}
+   for i, v in ipairs(x.dests) do
+    mdests[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))
+   x.mirror = mknew(x.new{mirror=x, init=segment.reset, dests=mdests})
   end
  end
 }
@@ -714,7 +714,7 @@ function segment:reset()
 end
 
 function segment:target_from(fx, fy)
- local rx, ry, af = self[self.current_idx]:target_from(fx, fy)
+ local rx, ry, af = self.dests[self.current_idx]:target_from(fx, fy)
  self.dest_x, self.dest_y = rx, ry
  return rx, ry, af
 end
@@ -725,7 +725,8 @@ function segment:update(x, y)
  if (rem > 0) rem -= 1
 
  if self:should_step(x, y) then
-  if self.current_idx == #self then
+  self.prev_x, self.prev_y = false, false
+  if self.current_idx == #self.dests then
    self.current_idx = self.loop_idx
    if (rem < 0) rem += 1
   else
@@ -760,22 +761,21 @@ end
 
 path = mknew {
  loop_idx = 1,
- -- [1..n]: destinations
+ -- segs[1..n]: segments or subpaths
  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
+   local msegs = {}
+   for i, v in ipairs(x.segs) do
+    msegs[i]=v.mirror
    end
-   x.mirror = path.new(mirrored)
+   x.mirror = path.new{mirror=x, loop_idx=x.loop_idx, segs=msegs}
   end
   x.init = function(y)
-   for i, v in ipairs(x) do
-    y[i]=v.new{}
+   local ysegs = {}
+   for i, v in ipairs(x.segs) do
+    ysegs[i]=v.new{}
    end
+   y.segs = ysegs
    y:reset()
   end
   mknew(x)
@@ -787,13 +787,13 @@ function path:reset()
 end
 
 function path:target_from(fx, fy)
- return self[self.current_idx]:target_from(fx, fy)
+ return self.segs[self.current_idx]:target_from(fx, fy)
 end
 
 function path:update(x, y)
  local idx = self.current_idx
- if self[idx]:update(x, y) then
-  if idx == #self then
+ if self.segs[idx]:update(x, y) then
+  if idx == #self.segs then
    self.current_idx = self.loop_idx
    return true
   else
@@ -1498,6 +1498,7 @@ ship_f = mknew(ship_m.new{
 })
 
 diamond_loop = segment.new{
+ dests = {
   destination.new{
    x_off_frac=0.25
   }, destination.new{
@@ -1507,6 +1508,14 @@ diamond_loop = segment.new{
   }, destination.new {
    y_off_frac = -0.25
   },
+ },
+}
+
+diamond_bounce = path.new{
+ segs = {
+  diamond_loop,
+  diamond_loop.mirror,
+ },
 }
 
 ship_mook = mknew(ship_f.new{
@@ -1530,7 +1539,7 @@ ship_skirmisher = mknew(ship_f.new{
  fire_off_y = 7,
  xmin = -8,
  xmax = 112,
- path = diamond_loop,
+ path = diamond_bounce,
 })
 
 function ship_skirmisher:reset_bounds()