very silly shot pattern

note that I need to re-call this whenever I have a new max hp

also note that vertmeter does not handle 1024 correctly. find out what max hp functions and hardcap it

arrays_profiling.p8

@@ -0,0 +1,504 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+-- prof: cpu cycle counter v1.4
+--  BY PANCELOR
+--[[------------------------
+
+
+use this cart to precisely
+measure code execution time
+
+--------------------------------
+         ★ overview ★
+--------------------------------
+| tab 0 | usage guide          |
+| tab 1 | (internals)          |
+| tab 2 | your code here       |
+--------------------------------
+
+
+-----------------------
+-- ★ usage guide ★ --
+-----------------------
+
+
+웃: i have two code snippets;
+    which one is faster?
+
+🐱: edit the last tab with your
+    snippets, then run the cart.
+    it will tell you precisely
+    how much cpu it takes to
+    run each snippet.
+
+    the results are also copied
+    to your clipboard.
+
+
+
+웃: what do the numbers mean?
+
+🐱: the cpu cost is reported
+    as lua and system cycle
+    counts. look up stat(1)
+    and stat(2) for more info.
+
+    if you're not sure, just
+    look at the first number.
+    lower is faster (better)
+
+
+
+웃: why "{locals={9}}"
+    in the example?
+
+🐱: accessing local variables
+    is faster than global vars.
+
+    so if your test involves
+    local variables, simulate
+    this by passing them in:
+
+      prof(function(a)
+        sqrt(a)
+      end,{ locals={9} })
+
+    /!\     /!\     /!\     /!\
+    local values from outside
+    the current scope are also
+    slower to access! example:
+
+      global = 4
+      local outer = 4
+      prof(function(x)
+        local _ = x --fast
+      end,function(x)
+        local _ = outer --slow
+      end,function(x)
+        local _ = global --slow
+      end,{ locals={4} })
+    /!\     /!\     /!\     /!\
+
+
+
+웃: can i do "prof(myfunc)"?
+
+🐱: no, this sometimes gives
+    wrong results! always use
+    inline functions:
+
+      prof(function()
+        --code for myfunc here
+      end)
+
+    as an example, "prof(sin)"
+    reports "-2" -- wrong! but
+    "prof(function()sin()end)"
+    correctly reports "4"
+
+    (see the technical notes at
+    the start of the next tab
+    for a brief explanation.
+    technically, "prof(myfunc)"
+    will work if myfunc was made
+    by the user, but you will
+    risk confusing yourself)
+
+
+
+---------------
+ ★ method 2 ★
+---------------
+
+
+
+this cart is based on
+code by samhocevar:
+https://www.lexaloffle.com/bbs/?pid=60198#p
+
+if you do this method, be very
+careful with local/global vars.
+it's very easy to accidentally
+measure the wrong thing.
+
+here's an example of how to
+measure cycles (ignoring this
+cart and using the old method)
+
+  function _init()
+    local a=11.2 -- locals
+
+    local n=1024
+    flip()
+    local tot1,sys1=stat(1),stat(2)
+    for i=1,n do   end --calibrate
+    local tot2,sys2=stat(1),stat(2)
+    for i=1,n do local _=sqrt(a) end --measure
+    local tot3,sys3=stat(1),stat(2)
+
+    function cyc(t0,t1,t2) return ((t2-t1)-(t1-t0))*128/n*256/stat(8)*256 end
+    local lua = cyc(tot1-sys1,tot2-sys2,tot3-sys3)
+    local sys = cyc(sys1,sys2,sys3)
+    print(lua.."+"..sys.."="..(lua+sys).." (lua+sys)")
+  end
+
+run this once, see the results,
+then change the "measure" line
+to some other code you want
+to measure.
+
+note: wrapping the code inside
+"_init()" is required, otherwise
+builtin functions like "sin"
+will be measured wrong.
+(the reason is explained at
+the start of the next tab)
+
+
+
+---------------
+ ★ method 3 ★
+---------------
+
+
+
+another way to measure cpu cost
+is to run something like this:
+
+  function _draw()
+    cls(1)
+    local x=9
+    for i=1,1000 do
+      local a=sqrt(x) --snippet1
+  --    local b=x^0.5 --snippet2
+    end
+  end
+
+while running, press ctrl-p to
+see the performance monitor.
+the middle number shows how much
+of cpu is being used, as a
+fraction. (0.60 = 60% used)
+
+now, change the comments on the
+two code snippets inside _draw()
+and re-run. compare the new
+result with the old to determine
+which snippet is faster.
+
+note: every loop iteration costs
+an additional 2 cycles, so the
+ratio of the two fractions will
+not match the ratio of the 
+execution time of the snippets.
+but this method can quickly tell
+you which snippet is faster.
+
+
+
+]]
+
+-->8
+--[[ profiler.lua
+more info: https://www.lexaloffle.com/bbs/?tid=46117
+
+usage:
+  prof(function()
+    memcpy(0,0x200,64)
+  end,function()
+    poke4(0,peek4(0x200,16))
+  end)
+
+passing locals:
+  prof(
+    function(a,b)
+      local c=(a+1)*(b+1)-1
+    end,
+    function(a,b)
+      local c=a*b+a+b
+    end,
+    {locals={3,5}}
+  )
+
+getting global/local variables exactly right
+is very tricky; you should always use inline
+functions like above; if you try e.g. prof(sin)
+the results will be wrong.
+
+
+# minutiae / notes to self:
+---------------------------
+doing this at top-level is awkward:
+  for _=1,n do       end -- calibrate
+  for _=1,n do sin() end -- measure
+b/c sin is secretly local at top-level,
+so it gives a misleading result (3 cycles).
+do it inside _init instead for a
+more representative result (4 cycles).
+
+## separate issue:
+------------------
+if you call prof(sin), it gives the wrong result (-2 cycles) because
+it's comparing sin() against noop() (not truly nothing).
+but we want the noop() there for normal inline prof() calls,
+to avoid measuring the cost of the indirection
+(calling func() from inside prof() is irrelevant to
+how cpu-expensive func()'s body is)
+]]
+
+-- prof(fn1,fn2,...,fnN,[opts])
+--
+-- opts.locals: values to pass
+-- opts.name: text label
+-- opts.n: number of iterations
+function prof(...)
+  local funcs={...}
+  local opts=type(funcs[#funcs])=="table" and deli(funcs) or {}
+
+  -- build output string
+  local msg=""
+  local function log(s)
+    msg..=s.."\n"
+  end
+
+  if opts.name then
+    log("prof: "..opts.name)
+  end
+  for fn in all(funcs) do
+    local dat=prof_one(fn,opts)
+    log(sub("  "..dat.total,-3)
+      .." ("
+      ..dat.lua
+      .." lua, "
+      ..dat.sys
+      .." sys)")
+  end
+
+  -- copy to clipboard
+  printh(msg,"@clip")
+  -- print + pause
+  cls()
+  stop(msg)
+end
+
+function prof_one(func, opts)
+  opts = opts or {}
+  local n = opts.n or 0x200 --how many times to call func
+  local locals = opts.locals or {} --locals to pass func
+
+  -- we want to type
+  --   local m = 0x80_0000/n
+  -- but 8MHz is too large to fit in a pico-8 number,
+  -- so we do (0x80_0000>>16)/(n>>16) instead
+  -- (n is always an integer, so n>>16 won't lose any bits)
+  local m = 0x80/(n>>16)
+  assert(0x80/m << 16 == n, "n is too small") -- make sure m didn't overflow
+  local fps = stat(8)
+
+  -- given three timestamps (pre-calibration, middle, post-measurement),
+  --   calculate how many more CPU cycles func() took compared to noop()
+  -- derivation:
+  --   T := ((t2-t1)-(t1-t0))/n (frames)
+  --     this is the extra time for each func call, compared to noop
+  --     this is measured in #-of-frames -- it will be a small fraction for most ops
+  --   F := 1/30 (seconds/frame) (or 1/60 if this test is running at 60fps)
+  --     this is just the framerate that the tests run at, not the framerate of your game
+  --   M := 256*256*128 = 0x80_0000 = 8MHz (cycles/second)
+  --     (PICO-8 runs at 8MHz; see https://www.lexaloffle.com/dl/docs/pico-8_manual.html#CPU)
+  --   cycles := T frames * F seconds/frame * M cycles/second
+  -- optimization / working around pico-8's fixed point numbers:
+  --   T2 := T*n = (t2-t1)-(t1-t0)
+  --   M2 := M/n = (M>>16)/(n>>16) := m (e.g. when n is 0x1000, m is 0x800)
+  --   cycles := T2*M2*F
+  local function cycles(t0,t1,t2)
+    local diff = (t2-t1)-(t1-t0)
+    local e1 = "must use inline functions -- see usage guide"
+    assert(0<=diff,e1)
+    local thresh = 0x7fff.ffff/(m/fps)
+    local e2 = "code is too large or slow -- try profiling manually with stat(1)"
+    assert(diff<=thresh,e2)
+    return diff*(m/fps)
+  end
+
+  local noop = function() end -- this must be local, because func is local
+  flip() --avoid flipping mid-measurement
+  local atot,asys=stat(1),stat(2)
+  for _=1,n do noop(unpack(locals)) end -- calibrate
+  local btot,bsys=stat(1),stat(2)
+  for _=1,n do func(unpack(locals)) end -- measure
+  local ctot,csys=stat(1),stat(2)
+
+  -- gather results
+  local tot=cycles(atot,btot,ctot)
+  local sys=cycles(asys,bsys,csys)
+  return {
+    lua=tot-sys,
+    sys=sys,
+    total=tot,
+  }
+end
+
+-->8
+-- your code here
+
+bigarr = (function()
+  local ret = {}
+  for i=1,100 do
+   ret[i]=i
+  end
+  return ret
+ end)()
+
+--edit me:
+prof(function()
+ local a, sum = bigarr, 0
+ for x=1,#a do
+  sum += a[x]
+ end
+end,function()
+ local a, sum = bigarr, 0
+ for v in all(a) do
+  sum += v
+ end
+end,function()
+ local a, sum = bigarr, 0
+ foreach(a, function(v) sum+= v end)
+end,{ locals={} })
+
+-- "locals" (optional) are
+-- passed in as args. see the
+-- usage guide for details.
+
+__label__
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collision_profiling.p8

@@ -0,0 +1,495 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+-- prof: cpu cycle counter v1.4
+--  BY PANCELOR
+--[[------------------------
+
+
+use this cart to precisely
+measure code execution time
+
+--------------------------------
+         ★ overview ★
+--------------------------------
+| tab 0 | usage guide          |
+| tab 1 | (internals)          |
+| tab 2 | your code here       |
+--------------------------------
+
+
+-----------------------
+-- ★ usage guide ★ --
+-----------------------
+
+
+웃: i have two code snippets;
+    which one is faster?
+
+🐱: edit the last tab with your
+    snippets, then run the cart.
+    it will tell you precisely
+    how much cpu it takes to
+    run each snippet.
+
+    the results are also copied
+    to your clipboard.
+
+
+
+웃: what do the numbers mean?
+
+🐱: the cpu cost is reported
+    as lua and system cycle
+    counts. look up stat(1)
+    and stat(2) for more info.
+
+    if you're not sure, just
+    look at the first number.
+    lower is faster (better)
+
+
+
+웃: why "{locals={9}}"
+    in the example?
+
+🐱: accessing local variables
+    is faster than global vars.
+
+    so if your test involves
+    local variables, simulate
+    this by passing them in:
+
+      prof(function(a)
+        sqrt(a)
+      end,{ locals={9} })
+
+    /!\     /!\     /!\     /!\
+    local values from outside
+    the current scope are also
+    slower to access! example:
+
+      global = 4
+      local outer = 4
+      prof(function(x)
+        local _ = x --fast
+      end,function(x)
+        local _ = outer --slow
+      end,function(x)
+        local _ = global --slow
+      end,{ locals={4} })
+    /!\     /!\     /!\     /!\
+
+
+
+웃: can i do "prof(myfunc)"?
+
+🐱: no, this sometimes gives
+    wrong results! always use
+    inline functions:
+
+      prof(function()
+        --code for myfunc here
+      end)
+
+    as an example, "prof(sin)"
+    reports "-2" -- wrong! but
+    "prof(function()sin()end)"
+    correctly reports "4"
+
+    (see the technical notes at
+    the start of the next tab
+    for a brief explanation.
+    technically, "prof(myfunc)"
+    will work if myfunc was made
+    by the user, but you will
+    risk confusing yourself)
+
+
+
+---------------
+ ★ method 2 ★
+---------------
+
+
+
+this cart is based on
+code by samhocevar:
+https://www.lexaloffle.com/bbs/?pid=60198#p
+
+if you do this method, be very
+careful with local/global vars.
+it's very easy to accidentally
+measure the wrong thing.
+
+here's an example of how to
+measure cycles (ignoring this
+cart and using the old method)
+
+  function _init()
+    local a=11.2 -- locals
+
+    local n=1024
+    flip()
+    local tot1,sys1=stat(1),stat(2)
+    for i=1,n do   end --calibrate
+    local tot2,sys2=stat(1),stat(2)
+    for i=1,n do local _=sqrt(a) end --measure
+    local tot3,sys3=stat(1),stat(2)
+
+    function cyc(t0,t1,t2) return ((t2-t1)-(t1-t0))*128/n*256/stat(8)*256 end
+    local lua = cyc(tot1-sys1,tot2-sys2,tot3-sys3)
+    local sys = cyc(sys1,sys2,sys3)
+    print(lua.."+"..sys.."="..(lua+sys).." (lua+sys)")
+  end
+
+run this once, see the results,
+then change the "measure" line
+to some other code you want
+to measure.
+
+note: wrapping the code inside
+"_init()" is required, otherwise
+builtin functions like "sin"
+will be measured wrong.
+(the reason is explained at
+the start of the next tab)
+
+
+
+---------------
+ ★ method 3 ★
+---------------
+
+
+
+another way to measure cpu cost
+is to run something like this:
+
+  function _draw()
+    cls(1)
+    local x=9
+    for i=1,1000 do
+      local a=sqrt(x) --snippet1
+  --    local b=x^0.5 --snippet2
+    end
+  end
+
+while running, press ctrl-p to
+see the performance monitor.
+the middle number shows how much
+of cpu is being used, as a
+fraction. (0.60 = 60% used)
+
+now, change the comments on the
+two code snippets inside _draw()
+and re-run. compare the new
+result with the old to determine
+which snippet is faster.
+
+note: every loop iteration costs
+an additional 2 cycles, so the
+ratio of the two fractions will
+not match the ratio of the 
+execution time of the snippets.
+but this method can quickly tell
+you which snippet is faster.
+
+
+
+]]
+
+-->8
+--[[ profiler.lua
+more info: https://www.lexaloffle.com/bbs/?tid=46117
+
+usage:
+  prof(function()
+    memcpy(0,0x200,64)
+  end,function()
+    poke4(0,peek4(0x200,16))
+  end)
+
+passing locals:
+  prof(
+    function(a,b)
+      local c=(a+1)*(b+1)-1
+    end,
+    function(a,b)
+      local c=a*b+a+b
+    end,
+    {locals={3,5}}
+  )
+
+getting global/local variables exactly right
+is very tricky; you should always use inline
+functions like above; if you try e.g. prof(sin)
+the results will be wrong.
+
+
+# minutiae / notes to self:
+---------------------------
+doing this at top-level is awkward:
+  for _=1,n do       end -- calibrate
+  for _=1,n do sin() end -- measure
+b/c sin is secretly local at top-level,
+so it gives a misleading result (3 cycles).
+do it inside _init instead for a
+more representative result (4 cycles).
+
+## separate issue:
+------------------
+if you call prof(sin), it gives the wrong result (-2 cycles) because
+it's comparing sin() against noop() (not truly nothing).
+but we want the noop() there for normal inline prof() calls,
+to avoid measuring the cost of the indirection
+(calling func() from inside prof() is irrelevant to
+how cpu-expensive func()'s body is)
+]]
+
+-- prof(fn1,fn2,...,fnN,[opts])
+--
+-- opts.locals: values to pass
+-- opts.name: text label
+-- opts.n: number of iterations
+function prof(...)
+  local funcs={...}
+  local opts=type(funcs[#funcs])=="table" and deli(funcs) or {}
+
+  -- build output string
+  local msg=""
+  local function log(s)
+    msg..=s.."\n"
+  end
+
+  if opts.name then
+    log("prof: "..opts.name)
+  end
+  for fn in all(funcs) do
+    local dat=prof_one(fn,opts)
+    log(sub("  "..dat.total,-3)
+      .." ("
+      ..dat.lua
+      .." lua, "
+      ..dat.sys
+      .." sys)")
+  end
+
+  -- copy to clipboard
+  printh(msg,"@clip")
+  -- print + pause
+  cls()
+  stop(msg)
+end
+
+function prof_one(func, opts)
+  opts = opts or {}
+  local n = opts.n or 0x200 --how many times to call func
+  local locals = opts.locals or {} --locals to pass func
+
+  -- we want to type
+  --   local m = 0x80_0000/n
+  -- but 8MHz is too large to fit in a pico-8 number,
+  -- so we do (0x80_0000>>16)/(n>>16) instead
+  -- (n is always an integer, so n>>16 won't lose any bits)
+  local m = 0x80/(n>>16)
+  assert(0x80/m << 16 == n, "n is too small") -- make sure m didn't overflow
+  local fps = stat(8)
+
+  -- given three timestamps (pre-calibration, middle, post-measurement),
+  --   calculate how many more CPU cycles func() took compared to noop()
+  -- derivation:
+  --   T := ((t2-t1)-(t1-t0))/n (frames)
+  --     this is the extra time for each func call, compared to noop
+  --     this is measured in #-of-frames -- it will be a small fraction for most ops
+  --   F := 1/30 (seconds/frame) (or 1/60 if this test is running at 60fps)
+  --     this is just the framerate that the tests run at, not the framerate of your game
+  --   M := 256*256*128 = 0x80_0000 = 8MHz (cycles/second)
+  --     (PICO-8 runs at 8MHz; see https://www.lexaloffle.com/dl/docs/pico-8_manual.html#CPU)
+  --   cycles := T frames * F seconds/frame * M cycles/second
+  -- optimization / working around pico-8's fixed point numbers:
+  --   T2 := T*n = (t2-t1)-(t1-t0)
+  --   M2 := M/n = (M>>16)/(n>>16) := m (e.g. when n is 0x1000, m is 0x800)
+  --   cycles := T2*M2*F
+  local function cycles(t0,t1,t2)
+    local diff = (t2-t1)-(t1-t0)
+    local e1 = "must use inline functions -- see usage guide"
+    assert(0<=diff,e1)
+    local thresh = 0x7fff.ffff/(m/fps)
+    local e2 = "code is too large or slow -- try profiling manually with stat(1)"
+    assert(diff<=thresh,e2)
+    return diff*(m/fps)
+  end
+
+  local noop = function() end -- this must be local, because func is local
+  flip() --avoid flipping mid-measurement
+  local atot,asys=stat(1),stat(2)
+  for _=1,n do noop(unpack(locals)) end -- calibrate
+  local btot,bsys=stat(1),stat(2)
+  for _=1,n do func(unpack(locals)) end -- measure
+  local ctot,csys=stat(1),stat(2)
+
+  -- gather results
+  local tot=cycles(atot,btot,ctot)
+  local sys=cycles(asys,bsys,csys)
+  return {
+    lua=tot-sys,
+    sys=sys,
+    total=tot,
+  }
+end
+
+-->8
+-- your code here
+
+--edit me:
+prof(function(b1,b2)
+	return 
+	  b1[1]<=b2[3]
+	  and b1[2]<=b2[4]
+	  and b1[3]>=b2[1]
+	  and b1[4]>=b2[2]
+end,function(b1, b2)
+	return 
+	  b1.x1<=b2.x2
+	  and b1.y1<=b2.y2
+	  and b1.x2>=b2.x1
+	  and b1.y2>=b2.y1
+end,{ locals={{1,1,1,1,x1=1,x2=1,y1=1,y2=1},{1,1,1,1,x1=1,x2=1,y1=1,y2=1}} })
+
+-- "locals" (optional) are
+-- passed in as args. see the
+-- usage guide for details.
+
+__label__
+00006660000000006660000000006660000006006000606066600000066060600660060000000000000000000000000000000000000000000000000000000000
+00006000060000006060666000006000000060006000606060600600600060606000006000000000000000000000000000000000000000000000000000000000
+00006660666000006060000000006660000060006000606066606660666066606660006000000000000000000000000000000000000000000000000000000000
+00000060060000006060666000000060000060006000606060600600006000600060006000000000000000000000000000000000000000000000000000000000
+00006660000000006660000000006660000006006660066060600000660066606600060000000000000000000000000000000000000000000000000000000000
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00006060000000006660000000006060000006006000606066600000066060600660060000000000000000000000000000000000000000000000000000000000
+00006060060000006060666000006060000060006000606060600600600060606000006000000000000000000000000000000000000000000000000000000000
+00006660666000006060000000006660000060006000606066606660666066606660006000000000000000000000000000000000000000000000000000000000
+00000060060000006060666000000060000060006000606060600600006000600060006000000000000000000000000000000000000000000000000000000000
+00000060000000006660000000000060000006006660066060600000660066606600060000000000000000000000000000000000000000000000000000000000
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
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+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+
+__sfx__
+030100003052500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505

vacuum_gambit.p8

@@ -59,90 +59,45 @@ function mknew(tt)
  return tt
 end
 
--- intrusive singly-linked list.
+-- call f on everything on list
--- cannot be nested or crossed!
+-- and return a new list of
-linked_list = mknew{
+-- items for which f was true.
- is_linked_list=true,
+function filtered(list, f)
- init = function(x)
+ local ret, n = {}, 0
-  x.next=nil
+ for v in all(list) do
-  x.tail=x
+  if f(v) then
- end,
+   n += 1
-}
+   ret[n] = v
-
-function linked_list:push_back(x)
- self.tail.next = x
- self.tail = x
-end
-
-function linked_list:push_front(x)
- if (not self.next) self.tail = x
- x.next = self.next
- self.next = x
-end
-
--- vore eats another linked list
--- by appending its contents.
--- the ingested linked is empty.
-function linked_list:vore(x)
- if (not x.next) return
- self.tail.next = x.next
- self.tail = x.tail
- x.next = nil
- x.tail = x
-end
-
--- strip calls f(x) for each
--- node, removing each node for
--- which f(x) returns true.
-function linked_list:strip(f)
- local p, n = self, self.next
- while n do
-  if f(n) then
-   p.next = n.next
-  else
-   p = n
   end
-  n = n.next
  end
- self.tail = p
+ return ret
 end
 
--- stripmove calls x:move() for
+-- call :move on everything on
--- each node, removing each node
+-- src and dump everything
--- for which x:move() is true.
+-- for which it returned true
-function linked_list:stripmove()
+-- onto dest.
- local p, n = self, self.next
+function appendmove(dest, src)
- while n do
+ local n = #dest
-  if n:move() then
+ for v in all(src) do
-   p.next = n.next
+  if v:move() then
-  else
+   n += 1
-   p = n
+   dest[n] = v
   end
-  n = n.next
- end
- self.tail = p
-end
-
--- optimized special case -
--- could be done with strip but
--- this avoids extra function
--- calls and comparisions since
--- draw isn't allowed to kill
--- the item
-function linked_list:draw()
- local n = self.next
- while n do
-  n:draw()
-  n = n.next
  end
 end
 
-
+-- like filtered, but calls
-function linked_list:pop_front()
+-- :move on stuff in the list
- local ret = self.next
+-- instead of taking a func arg.
- if (not ret) return
+function filtermoved(list)
- self.next = ret.next
+ local ret, n = {}, 0
- if (not ret.next) ret.tail = nil
+ for v in all(list) do
+  if v:move() then
+   n += 1
+   ret[n] = v
+  end
+ end
  return ret
 end
 
@@ -156,12 +111,12 @@ function _init()
 end
 
 function once_next_frame(f)
- new_events:push_back{
+ add(new_events, {
   move = function()
    f()
    return true
   end,
- }
+ })
 end
 
 -- health gradients for 1..5 hp
@@ -175,20 +130,20 @@ hpcols_lut = csv[[36
 -- call after any change to maxhp
 -- configures health gradient
 function init_hpcols()
- hpcols = hpcols_lut[min(primary_ship.maxhp,6)]
+ hpcols = hpcols_lut[min(primary_ship.maxhp,5)]
 end
 
 function wipe_game()
  xpwhoosh = nil
  primary_ship = player.new()
  init_hpcols()
- eships = linked_list.new()
+ eships = {}
- pbullets = linked_list.new()
+ pbullets ={}
- ebullets = linked_list.new()
+ ebullets ={}
- intangibles_fg = linked_list.new()
+ intangibles_fg = {}
- intangibles_bg = linked_list.new()
+ intangibles_bg = {}
- events = linked_list.new()
+ events = {}
- new_events = linked_list.new()
+ new_events = {}
 	primary_ship.main_gun = zap_gun_p.new()
  primary_ship.main_gun:peel()
  gframe = 0
@@ -241,10 +196,11 @@ function updategame()
   current_wave = flotilla.new()
   current_wave:load(rnd() > 0.5 and 7 or 0, 0, min(ones(waves_complete)\2, 4))
  end
- events:vore(new_events)
+ events = filtermoved(events)
- for _, lst in ipairs{events, intangibles_bg, eships} do
+ appendmove(events, new_events)
-  lst:stripmove()
+ new_events = {}
- end
+ intangibles_bg = filtermoved(intangibles_bg)
+ eships = filtermoved(eships)
 
 	-- eship collider will be used
  -- both for pship and pbullets.
@@ -255,29 +211,30 @@ function updategame()
   local pbox = hurtbox(ps)
   for es in eship_collider:iterate_collisions(pbox) do
    ps:hitship(es)
-   if(es:hitship(ps)) eship_collider:yoink(es)
+   es:hitship(ps)
   end
-  ebullets:strip(function(eb)
+  ebullets = filtered(ebullets, function(eb)
-   if (eb:move()) return true
+   if (not eb:move()) return
-   if (not collides(pbox, hurtbox(eb))) return
+   if (not collides(pbox, hurtbox(eb))) return true
    ps:hitbullet(eb)
-   return eb:hitship(ps)
+   return not eb:hitship(ps)
   end)
  else
-  ebullets:stripmove()
+  ebullets=filtermoved(ebullets)
  end
 
- pbullets:strip(function(pb)
+ pbullets = filtered(pbullets, function(pb)
-  if (pb:move()) return true
+  if (not pb:move()) return
   for es in eship_collider:iterate_collisions(hurtbox(pb)) do
-   if (es:hitbullet(pb)) eship_collider:yoink(es)
+   es:hitbullet(pb)
-   if (pb:hitship(es)) return true
+   if (pb:hitship(es)) return
   end
+  return true
  end)
  
- intangibles_fg:stripmove()
+ intangibles_fg = filtermoved(intangibles_fg)
 
-	if waves_complete == 32767 and not eships.next and not ebullets.next and not events.next then
+	if waves_complete == 32767 and #eships == 0 and #ebullets == 0 and #events == 0 then
 	  game_state = win
 	end
 	if (ps.dead) game_state = lose
@@ -345,15 +302,6 @@ function puke(item, indent, seen, hidekey)
  end
  local xpfx = pfx.." "
 
- if item.is_linked_list then
-  local ret,n = "linked_list <",0
-  item:strip(function(x)
-   n += 1
-   ret ..= xpfx..tostr(n)..": "..puke(x, indent+2, seen, "next")
-  end)
-  return ret..pfx..">"
- end
-
  local ret = "{"
  for k, v in pairs(item) do
   if (k ~= hidekey) ret ..= xpfx..tostr(k)..": "..puke(v, indent+2, seen)
@@ -373,8 +321,10 @@ end
 function drawgame()
  clip(0,0,112,128)
  rectfill(0,0,112,128,0)
- for drawable in all{intangibles_bg, pbullets, primary_ship, eships, ebullets, intangibles_fg} do
+ for drawables in all{intangibles_bg, pbullets, {primary_ship}, eships, ebullets, intangibles_fg} do
-  drawable:draw()
+  for d in all(drawables) do
+   d:draw()
+  end
  end
  clip(0,0,128,128)
  drawhud()
@@ -586,9 +536,10 @@ function ship_m:constrain(p, dp, pmin, pmax, want)
 end
 
 function ship_m:move()
+ if (self.dead) return;
  self:refresh_shield()
  local dx, dy, shoot_spec1, shoot_spec2 = self:act()
- local sg, xm, ym = self.special_guns, self.xmomentum, self.ymomentum
+ local sg, xm, ym, sp = self.special_guns, self.xmomentum, self.ymomentum, self.sparks
  dx = self:constrain(self.x, xm, self.xmin, self.xmax, dx)
  dy = self:constrain(self.y, ym, self.ymin, self.ymax, dy)
  self:maybe_shoot(self.main_gun)
@@ -596,7 +547,7 @@ function ship_m:move()
   if (shoot_spec1) self:maybe_shoot(sg[1])
   if (shoot_spec2) self:maybe_shoot(sg[2])
  end
- spark(self.sparks, self.x + 4*self.size, self.y + 4*self.size, dx*2.5, dy*2.5, self.sparkodds)
+ if(sp) spark(sp, self.x + 4*self.size, self.y + 4*self.size, dx*2.5, dy*2.5, self.sparkodds)
  xm = self:calc_velocity(xm, dx)
  ym = self:calc_velocity(ym, dy)
 
@@ -605,7 +556,7 @@ function ship_m:move()
  self.xmomentum = xm
  self.ymomentum = ym
 
- return false
+ return true
 end
 
 function ship_m:draw()
@@ -617,12 +568,8 @@ end
 
 function hurtbox(ship)
  local h = ship.hurt
- return {
+ local x1,y1 = ship.x + h.x_off, ship.y+h.y_off
-  x=ship.x + h.x_off,
+ return {x1=x1, y1=y1, x2=x1+h.width, y2=y1+h.height}
-  y=ship.y + h.y_off,
-  width=h.width,
-  height=h.height
- }
 end
 
 function ship_m:maybe_shoot(gun)
@@ -671,14 +618,6 @@ end
 -->8
 -- bullet and gun behaviors
 
-function player_blt_cat()
- return pbullets
-end
-
-function enemy_blt_cat()
- return ebullets
-end
-
 -- x, y: position
 -- dx, dy: movement (linear)
 -- f: frames remaining; nil for no limit
@@ -691,9 +630,9 @@ end
 --   details, check impl
 -- damage -- damage to do to
 --   a ship that gets hit
--- category -- function that
+-- category -- string naming
---   returns which bullet list
+--   which bullet list to spawn
---   to spawn onto
+--   onto, from _ENV
 -- hitship -- event handler,
 --   takes ship as argument.
 --   default: die, return true.
@@ -826,13 +765,9 @@ function bullet_base:hitship(_)
 end
 
 function bullet_base:move()
- local x,y,f = self.x + self.dx, self.y+self.dy,self.f
+ local x,y = self.x + self.dx, self.y+self.dy
  self.x,self.y=x,y
- if f then
+ return (y<=128) and (y >= -16) and (x <= 128) and (x >= -16)
-  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()
@@ -842,7 +777,7 @@ end
 function bullet_base:spawn_at(x, y)
  self.x = x - self.x_off
  self.y = y - self.y_off
- self.category():push_back(self)
+ add(_ENV[self.category], self)
 end
 
 function gun_base:shoot(x, y)
@@ -912,7 +847,7 @@ zap_p = mknew(bullet_base.new{
 
  hitship = const_fxn(true),
 
- category = player_blt_cat,
+ category = "pbullets",
 })
 
 zap_gun_p = mknew(gun_base.new{
@@ -954,7 +889,7 @@ blast = mknew(bullet_base.new{
   if self.damage > 0 and not self.awaitcancel then
    self.awaitcancel = true
    once_next_frame(function()
-    new_events:push_back{
+    add(new_events, {
      wait = 4,
      obj = self,
      saved_dmg = self.damage,
@@ -965,13 +900,13 @@ blast = mknew(bullet_base.new{
        return true
       end
      end,
-    }
+    })
     self.damage = 0
     self.awaitcancel = false
    end)
   end
  end,
- category=player_blt_cat
+ category="pbullets"
 })
 
 blast_gun = mknew(gun_base.new{
@@ -1010,14 +945,14 @@ protron_e = mknew(bullet_base.new{
  y_off = 4,
  
  damage = 1,
- category = enemy_blt_cat,
+ category = "ebullets",
 })
 
 protron_p = mknew(protron_e.new{
  sprite=23,
  dym = -1,
  y_off = 0,
- category=player_blt_cat,
+ category="pbullets",
 })
 
 protron_gun_e = mknew(gun_base.new{
@@ -1064,13 +999,13 @@ vulcan_e = mknew(bullet_base.new{
  y_off = 0,
  
  damage = 0.5,
- category=enemy_blt_cat
+ category="ebullets"
 })
 
 vulcan_p = mknew(vulcan_e.new{
  sprite=22,
  y_off = 4,
- category=player_blt_cat
+ category="pbullets"
 })
 
 vulcan_gun_e = mknew(gun_base.new{
@@ -1087,7 +1022,7 @@ machine_gun_e = mknew(vulcan_gun_e.new{
  icon = 38,
  clip_size = 12,
  clip_interval = 0x0.005a,
- shots = {{{0, 2}}, {{0, -2}}}
+ shots = {{{0.0625, 2}}, {{-0.0625, -2}}}
 })
 
 vulcan_gun_p = mknew(vulcan_gun_e.new{
@@ -1129,8 +1064,8 @@ player = mknew(ship_m.new{
  boss = true,  -- dramatic special effects
  
  -- health
- hp = 3, -- current health, non-regenerating
+ hp = 1024, -- current health, non-regenerating
- maxhp = 3, -- player only; other ships never heal
+ maxhp = 1024, -- player only; other ships never heal
  shield = 2, -- regenerates
  maxshield = 2,
 
@@ -1406,21 +1341,19 @@ end
 -->8
 -- collisions
 
--- box: x, y, width, height
+-- box: x1, y1, x2, y2
-
+function collides(b1, b2)
-function collides(box1, box2)
+	return
-	return not (
+   b1.y1<=b2.y2
-	  box1.x>box2.x+box2.width
+	  and b1.y2>=b2.y1
-	  or box1.y>box2.y+box2.height
+	  and b1.x1<=b2.x2
-	  or box1.x+box1.width<box2.x
+	  and b1.x2>=b2.x1
-	  or box1.y+box1.height<box2.y)
 end
 
 collider = mknew{
  init = function(x)
-  x.suppress = {}
+  local from = x.from
-  local p, n = x.from, x.from.next
+  for n in all(from) do
-  while n do
    -- insert
    for i in all(collider_indexes(hurtbox(n))) do
     local a = x[i]
@@ -1430,35 +1363,20 @@ collider = mknew{
     end
     add(a, n)
    end
-   -- prepare yoink
-   n.prev = p
-   p = n
-   n = n.next
   end
  end,
 }
 
 function collider_indexes(box)
- local ret = {}
+ local ret, ylo, yhi = {}, box.y1\8, box.y2\8
- for x = box.x\8, (box.x+box.width)\8 do
+ for x = box.x1\8, box.x2\8 do
-  for y = box.y\8, (box.y+box.height)\8 do
+  for y = ylo, yhi do
-   add(ret, x+256*y)
+   add(ret, x+(y<<8))
   end
  end
  return ret
 end
 
-function collider:yoink(item)
- self.suppress[item]=true
- local p,n = item.prev,item.next
- p.next = n
- if n then
-  n.prev = p
- else
-  self.from.tail = p
- end
-end
-
 function collider:iterate_collisions(box)
  local seen = { }
  local bucket_ids = collider_indexes(box)
@@ -1474,7 +1392,7 @@ function collider:iterate_collisions(box)
     bi += 1
     if not seen[candidate] then
      seen[candidate] = true
-     if (not self.suppress[candidate] and collides(box, hurtbox(candidate))) return candidate
+     if (not candidate.dead and collides(box, hurtbox(candidate))) return candidate
     end
    end -- done with this bucket
    bi=1
@@ -1561,7 +1479,7 @@ function flotilla:load(ulc_cx, ulc_cy, lvl)
    for s in all(row) do
     counts[s.ship_t] += 1
     s.x,s.y=rnd_spawn_loc()
-    eships:push_back(s)
+    add(eships, s)
    end
    add(rows, row)
   end
@@ -1648,13 +1566,13 @@ blip_fx = mknew{
 }
 
 function blip_fx:move()
- if (self.cancel) return true
+ if (self.cancel) return
  self.frames -= 1
  if self.frames < 0 then
   self.obj.fx_pal = nil
-  return true
+  return
  end
- return false
+ return true
 end
 
 function blip_fx:abort()
@@ -1675,7 +1593,7 @@ end
 function blip(obj, col)
  obj.fx_pal = blip_pals[col]
  if (obj.___fx_pal_event) obj.___fx_pal_event:abort() 
- events:push_back(blip_fx.new{frames=3, obj=obj})
+ add(events, blip_fx.new{frames=3, obj=obj})
 end
 
 bossspark = split"7,7,10,10,9,9,9,8,8,8,2,2,5,5"
@@ -1699,27 +1617,28 @@ spark_particle=mknew{}
 
 function spark_particle:move()
  if (rnd(4) < 1) self.sidx += 1
- if (self.sidx > #self.sprs) return true
+ if (self.sidx > #self.sprs) return
  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)
+ return true
 end
 function spark_particle:draw()
  pset(self.x,self.y,self.sprs[self.sidx])
 end
 
 function spark(sprs, x, y, dx, dy, odds, fg)
- if (sprs==nil or flr(rnd(odds) or (abs(dx) < 0.5 and abs(dy))) ~= 0) return
+ if ((dx > -0.5 and dx < 0.5 and dy > -0.5 and dy < 0.5) or rnd(odds) >= 1) return
  local target = fg and intangibles_fg or intangibles_bg
- target:push_back(spark_particle.new{
+ target[#target+1] = spark_particle.new{
   x = x + rnd(4) - 2,
   y = y + rnd(4) - 2,
   sprs = sprs,
   sidx = 1,
   dx = dx * rnd(2),
   dy = dy * rnd(2),
- })
+ }
 end
 -->8
 -- powerups
@@ -1729,7 +1648,7 @@ xp_gem = mknew(bullet_base.new{
  dy = 0.75,
  width=1, -- not used for spr but
  height=1,-- bullet_base uses it
- category = enemy_blt_cat,
+ category = "ebullets",
  damage = 0,
  hurt = {
   x_off = -2,