bye, chasey!

chasey can be replaced by a path segment now
test player-relative paths
2025-07-06 22:28:41 -07:00 · 2025-07-06 21:07:36 -07:00 · 2025-07-06 20:49:05 -07:00 · 2025-07-06 20:32:43 -07:00 · 2025-07-06 20:02:21 -07:00 · 2025-07-06 19:25:43 -07:00
8 changed files with 3659 additions and 794 deletions
--- a/arrays_profiling.p8
+++ b/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.
+
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--- a/collision_profiling.p8
+++ b/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__
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+
+__sfx__
+030100003052500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505
--- a/collisiontest.p8
+++ b/collisiontest.p8
@@ -0,0 +1,229 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+bx0=0
+by0=0
+bx1=127
+by1=127
+lx0=0
+ly0=0
+lx1=127
+ly1=127
+
+-->8
+
+function collides()
+	local tmin,tmax=0,1
+	
+	local ldx,ldy=lx1-lx0,ly1-ly0
+	
+	
+	-- x
+	if ldx==0 then
+		if (lx0<bx0 or lx0>bx1) return
+	else
+ 	local tx0=(bx0-lx0)/ldx
+ 	local tx1=(bx1-lx0)/ldx
+ 	if (tx0 > tx1) tx0,tx1=tx1,tx0
+ 	if (tmin < tx0) tmin=tx0
+ 	if (tmax > tx1) tmax=tx1
+ end
+ 
+	if ldy==0 then
+		if (ly0<by0 or ly0>by1) return
+	else
+ 	local ty0=(by0-ly0)/ldy
+ 	local ty1=(by1-ly0)/ldy
+ 	if (ty0 > ty1) ty0,ty1=ty1,ty0
+ 	if (tmin < ty0) tmin=ty0
+ 	if (tmax > ty1) tmax=ty1
+ end 
+ 
+ if (tmax < tmin) return
+ return tmin,tmax
+end
+
+
+-->8
+function _init()
+	poke(0x5f2d,1) -- enable mouse
+end
+
+function _bounce_screen(x)
+ return _bounce(x*128,128)
+end
+function _bounce(x,mx)
+	x=x%(mx * 2)
+	if (x>=mx)return mx-(x-mx)
+	return x
+end
+
+function _to_halfopen(x0,x1)
+ -- turn two numbers into a
+ -- half-open integer range
+ x0=flr(x0)
+ x1=flr(x1)
+ local lo=min(x0,x1)
+ local hi=max(x0,x1)
+ if (hi==lo) return lo,hi
+ return lo,hi-1
+end
+
+function _update60()
+ local t=time()/16
+ 
+	local bx0_=_bounce_screen(t*1)
+	local by0_=_bounce_screen(t*2)
+	local bx1_=_bounce_screen(t*3)
+	local by1_=_bounce_screen(t*4)
+	
+	bx0,bx1=_to_halfopen(bx0_,bx1_)
+	by0,by1=_to_halfopen(by0_,by1_)
+	
+	update_line()
+	
+	--[[
+ local lx0_=_bounce_screen(t*1.5)
+ local ly0_=_bounce_screen(t*2.5)
+ local lx1_=_bounce_screen(t*3.5)
+ local ly1_=_bounce_screen(t*4.5)
+	
+	lx0,lx1=lx0_,lx1_
+	ly0,ly1=ly0_,ly1_
+	]]--
+end
+
+was_down=false
+last_mx,last_my=nil,nil
+
+function update_line()
+ local mx,my=stat(32),stat(33)
+ local is_down=stat(34)!=0
+
+ if is_down then
+  if was_down then
+   lx1,ly1=mx,my
+  else
+  	lx0,ly0=mx,my
+  end
+ end
+ was_down=is_down
+ last_mx,last_my=mx,my
+end
+-->8
+function _draw()
+ cls(0)
+	rect(bx0,by0,bx1,by1,6)
+	--quickzot(lx1,ly1,2,lx1-lx0,ly1-ly0,10,9,8)
+ linefill(lx0, ly0, lx1, ly1, 2, 9)
+	line(lx0,ly0,lx1,ly1,2)
+	local cmin, cmax = collides()
+	if cmin then
+	 local dx,dy=lx1-lx0,ly1-ly0
+	 line(lx0 + dx*cmin,
+	      ly0 + dy*cmin,
+	      lx0 + dx*cmax,
+	      ly0 + dy*cmax,
+	      11)
+	 pset(lx0 + dx*cmin,
+	      ly0 + dy*cmin,
+	      12)
+	end
+	
+	pset(last_mx,last_my,7)
+end
+-->8
+function zot_one(x, y, r, ir, dx, dy, hot, warm)
+ local x0, y0 = x-dx, y-dy
+ local rx,ry,irx,iry=r*sgn(dx),r*sgn(dy),ir*sgn(dx),ir*sgn(dy)
+ if warm then
+  line(x0+irx,y0-ry,x+rx,y-iry,warm)
+  line(x0-rx,y0+iry,x-irx,y+ry,warm)
+  --line(x0-rx,y0-ry,x+rx,y+ry,warm)
+ end
+ line(x0,y0,x+rx,y-iry,hot)
+ line(x0,y0,x-irx,y+ry,hot)
+ --line(x0,y0,x+rx,y+ry,hot)
+end
+
+function zot(x,y,r,dx,dy,hot,warm,cold)
+ local x0,y0,sdx,sdy=x-dx,y-dy,sgn(dx),sgn(dy)
+ local rx,ry=r*sdx,r*sdy
+ if cold then
+  rectfill(x0-rx,y0-ry,x0+rx,y0+ry,cold)
+  local sdxh,sdyh=sdx/2,sdy/2
+  line(x0-rx-sdxh,y0+ry+sdyh,x-rx,y+ry,cold)
+  line(x0+rx+sdxh,y0-ry-sdyh,x+rx,y-ry,cold)
+ end
+ for i=-r,r do
+  line(x0+i*sdx,y0-ry,x+rx,y-i*sdy,warm)
+  line(x0-rx,y0+i*sdy,x-i*sdx,y+ry,warm)
+ end
+ for i=-r,r do
+  line(x0,y0,x+rx,y-i*sdy,hot)
+  line(x0,y0,x-i*sdx,y+ry,hot)
+ end
+end
+
+function quickzot(x,y,r,dx,dy,hot,warm,cold)
+ local x0, y0, r2 = x-dx, y-dy, r/2
+ rectfill(x0-0.5-r2, y0-0.5-r2, x0+r2+0.5, y0+r2+0.5, cold)
+ local a = atan2(dx,dy)-0.25
+ local tdx,tdy=cos(a), sin(a)
+ for i=-r*0.65,r*0.65,0.65 do
+  line(x0+i*tdx, y0+i*tdy, x+i*tdx, y+i*tdy, warm)
+ end
+ rectfill(x-r2,y-r2,x+r2,y+r2,hot)
+end
+
+-- linefill x0 y0 x1 y1 r [col]
+-- draw a thicc line
+-- https://www.lexaloffle.com/bbs/?tid=39016
+function linefill(ax,ay,bx,by,r,c)
+ if(c) color(c)
+ local dx,dy=bx-ax,by-ay
+ -- avoid overflow
+ -- credits: https://www.lexaloffle.com/bbs/?tid=28999
+ local d,n = abs(dx),abs(dy)
+ if (d<n) d,n=n,d
+ n/=d
+ d*=sqrt(n*n+1)
+ if(d<0.001) return
+ local ca,sa=dx/d,-dy/d
+
+ -- polygon points
+ local s={
+  {0,-r},{d,-r},{d,r},{0,r}
+ }
+ local u,v,spans=s[4][1],s[4][2],{}
+ local x0,y0=ax+u*ca+v*sa,ay-u*sa+v*ca
+ for i=1,4 do
+  local u,v=unpack(s[i])
+  local x1,y1=ax+u*ca+v*sa,ay-u*sa+v*ca
+  local _x1,_y1=x1,y1
+  if(y0>y1) x0,y0,x1,y1=x1,y1,x0,y0
+  local dx=(x1-x0)/(y1-y0)
+  if(y0<0) x0-=y0*dx y0=-1
+  local cy0=y0\1+1
+  -- sub-pix shift
+  x0+=(cy0-y0)*dx
+  for y=y0\1+1,min(y1\1,127) do
+   -- open span?
+   local span=spans[y]
+   if span then
+       rectfill(x0,y,span,y)
+   else
+       spans[y]=x0
+   end
+   x0+=dx
+  end
+  x0,y0=_x1,_y1
+ end
+end
+__gfx__
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--- a/magnitest.p8
+++ b/magnitest.p8
@@ -0,0 +1,245 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+--magnitest.p8
+--accuracy and perf tests for
+--vector calculation logic
+
+-- profiler says 67 cycles
+-- 39 lua, 28 system
+function bbs28999alg(dx, dy)
+  local d = max(abs(dx),abs(dy))
+  local n = min(abs(dx),abs(dy)) / d
+  return sqrt(n*n + 1) * d
+end
+
+-- profiler says 56 cycles
+-- 24 lua, 32 system
+function bbs28999algopt(dx, dy)
+  local d,n=abs(dx),abs(dy)
+  if (d<n) d,n=n,d
+  n/=d
+  return (n*n + 1)^0.5 * d
+end
+
+-- profiler says 54 cycles
+-- 26 lua, 28 system
+function bbs28999algopt2(dx, dy)
+  local d,n=abs(dx),abs(dy)
+  if (d<n) d,n=n,d
+  n/=d
+  return sqrt(n*n + 1) * d
+end
+
+
+-- profiler says 18 cycles
+-- 18 lua, 0 system
+function trigalg(dx, dy)
+ local s = sin(atan2(dx,dy))
+ if (s==0) return abs(dx)
+ return abs(dy/s)
+end
+-->8
+function _init()
+ gdx,gdy=0,0
+ acc=1
+ magnitude = 1
+ tresult=0
+ bresult=0
+ delta=0
+ dp=0
+end
+
+function _update60()
+ if (btn(0)) gdx -= acc
+ if (btn(1)) gdx += acc
+ if (btn(2)) gdy -= acc
+ if (btn(3)) gdy += acc
+ if (btn(4) and btn(5)) gdx,gdy=0,0
+ gdx=mid(-16000,16000,gdx)
+ gdy=mid(-16000,16000,gdy)
+
+ if btn() == 0 or btn(4) then
+  acc = 1
+ elseif btn(5) then
+  acc *= 1.05
+ else
+  acc *= 1.02
+ end
+ if (acc > 1024) acc=1024
+
+ local a,b=abs(gdx),abs(gdy)
+ if (b>a) a,b=b,a
+ magnitude = 1
+ while magnitude < a/64 do
+  magnitude *= 2
+ end
+
+ bresult=bbs28999algopt2(gdx,gdy)
+ tresult=trigalg(gdx,gdy)
+ delta=tresult-bresult
+ dp=(2*abs(delta)/abs(abs(bresult)+abs(tresult)))*100
+ if (delta == 0) dp=0
+end
+
+cols = {
+ 6,7,
+ [4]=10,
+ [8]=9,
+ [16]=4,
+ [32]=14,
+ [64]=15,
+ [128]=11,
+ [256]=12,
+ [512]=13,
+ [1024]=8,
+}
+
+function _draw()
+ cls()
+ camera()
+ print("x: "..tostr(gdx).."  y: "..tostr(gdy).."\nbase: "..tostr(bresult).."\ntrig: "..tostr(tresult).."\n\ndiff: "..tostr(delta).."\n   %:"..tostr(dp),0,0,13)
+ print("⬆️⬇️⬅️➡️:move  ❎:fast 🅾️:slow\n❎+🅾️:reset position",0,117,12)
+ camera(-63,-63)
+ line(0,0,gdx/magnitude,gdy/magnitude,cols[magnitude] or 2)
+ rectfill(0,0,gdx/magnitude,0,5)
+ rectfill(0,0,0,gdy/magnitude,5)
+end
+
+__gfx__
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+
--- a/magnitest.p8.png
+++ b/magnitest.p8.png
--- a/profiling.p8
+++ b/profiling.p8
@@ -0,0 +1,501 @@
+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(dx,dy)
+  local d = max(abs(dx),abs(dy))
+  local n = min(abs(dx),abs(dy)) / d
+  return sqrt(n*n + 1) * d
+end,function(dx, dy)
+  local d,n=abs(dx),abs(dy)
+  if (d<n) d,n=n,d
+  n/=d
+  return (n*n + 1)^0.5 * d
+end,function(dx,dy)
+  local d,n=abs(dx),abs(dy)
+  if (d<n) d,n=n,d
+  n/=d
+  return sqrt(n*n + 1) * d
+end,function(dx,dy)
+ local s = sin(atan2(dx,dy))
+ if (s==0) return abs(dx)
+ return abs(dy/s)
+end,{ locals={3,4} })
+
+-- "locals" (optional) are
+-- passed in as args. see the
+-- usage guide for details.
+
+__label__
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+
+__sfx__
+030100003052500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505005050050500505
--- a/vacuum_gambit.p8
+++ b/vacuum_gambit.p8
--- a/zotprofiling.p8
+++ b/zotprofiling.p8
@@ -0,0 +1,598 @@
+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(...)
+  cls()
+  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
+  while btn() == 0 do
+   flip()
+  end
+  color(6)
+  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:
+
+function linefill(ax,ay,dx,dy,r,c)
+ if(c) color(c)
+ -- avoid overflow
+ -- credits: https://www.lexaloffle.com/bbs/?tid=28999
+ local d,n = abs(dx),abs(dy)
+ if (d<n) d,n=n,d
+ n/=d
+ d*=sqrt(n*n+1)
+ if(d<0.001) return
+ local ca,sa=dx/d,-dy/d
+
+ -- polygon points
+ local s={
+  {0,-r},{d,-r},{d,r},{0,r}
+ }
+ local u,v,spans=s[4][1],s[4][2],{}
+ local x0,y0=ax+u*ca+v*sa,ay-u*sa+v*ca
+ for i=1,4 do
+  local u,v=unpack(s[i])
+  local x1,y1=ax+u*ca+v*sa,ay-u*sa+v*ca
+  local _x1,_y1=x1,y1
+  if(y0>y1) x0,y0,x1,y1=x1,y1,x0,y0
+  local dx=(x1-x0)/(y1-y0)
+  if(y0<0) x0-=y0*dx y0=-1
+  local cy0=y0\1+1
+  -- sub-pix shift
+  x0+=(cy0-y0)*dx
+  for y=y0\1+1,min(y1\1,127) do
+   -- open span?
+   local span=spans[y]
+   if span then
+       rectfill(x0,y,span,y)
+   else
+       spans[y]=x0
+   end
+   x0+=dx
+  end
+  x0,y0=_x1,_y1
+ end
+end
+
+function quickzot(x,y,r,dx,dy,hot,warm,cold)
+ local x0, y0, r2 = x-dx, y-dy, r/2
+ rectfill(x0-0.5-r2, y0-0.5-r2, x0+r2+0.5, y0+r2+0.5, cold)
+ local a = atan2(dx,dy)-0.25
+ local tdx,tdy=cos(a), sin(a)
+ for i=-r*0.65,r*0.65,0.65 do
+  line(x0+i*tdx, y0+i*tdy, x+i*tdx, y+i*tdy, warm)
+ end
+ rectfill(x-r2,y-r2,x+r2,y+r2,hot)
+end
+
+function zot(x,y,r,dx,dy,hot,warm,cold)
+ local x0,y0,sdx,sdy=x-dx,y-dy,sgn(dx),sgn(dy)
+ local rx,ry=r*sdx,r*sdy
+ if cold then
+  rectfill(x0-rx,y0-ry,x0+rx,y0+ry,cold)
+  local sdxh,sdyh=sdx/2,sdy/2
+  line(x0-rx-sdxh,y0+ry+sdyh,x-rx,y+ry,cold)
+  line(x0+rx+sdxh,y0-ry-sdyh,x+rx,y-ry,cold)
+ end
+ for i=-r,r do
+  line(x0+i*sdx,y0-ry,x+rx,y-i*sdy,warm)
+  line(x0-rx,y0+i*sdy,x-i*sdx,y+ry,warm)
+ end
+ for i=-r,r do
+  line(x0,y0,x+rx,y-i*sdy,hot)
+  line(x0,y0,x-i*sdx,y+ry,hot)
+ end
+end
+
+function respr(x,y,dx,dy,r,s)
+ if (r==0) r=0.5
+ local n=ceil(max(abs(dx),abs(dy))/r/2)
+ local d1x,d1y=dx/n,dy/n
+ r/=4
+ for i=1,n do
+  spr(s,x,y,r,r)
+  x+=d1x
+  y+=d1y
+ end
+ pal()
+ spr(s,x,y,r,r)
+end
+
+darkpal = {
+ [7]=4,
+ [9]=2,
+ [10]=4,
+ [8]=2
+}
+
+prof(function(dx, dy, r)
+  linefill(32,32,dx,dy,r,10)
+end,function(dx, dy, r)
+  quickzot(96,32,r,dx,dy,10,9,8)
+end,function(dx,dy,r)
+  zot(32,96,r,dx,dy,10,9,8)
+end,function(dx,dy,r)
+  pal(darkpal)
+  respr(96,96,dx,dy,r,r)
+end,{ locals={4,-9,2} })
+
+-- "locals" (optional) are
+-- passed in as args. see the
+-- usage guide for details.
+
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Author	SHA1	Message	Date
Kistaro Windrider	6b5748dae7	bye, chasey! chasey can be replaced by a path segment now	2025-07-06 22:28:41 -07:00
Kistaro Windrider	1d816e0c6a	test player-relative paths	2025-07-06 21:07:36 -07:00
Kistaro Windrider	be321db355	mirror paths for skirmishers in the right half	2025-07-06 20:49:05 -07:00
Kistaro Windrider	7c3fc833df	fix paths segment/path update logic was somewhat backwards. the result is definitely good enough for the kind of movements I want!	2025-07-06 20:32:43 -07:00
Kistaro Windrider	10aef3b1ed	paths sort of work but not really figure out why they do not show the expected patterns	2025-07-06 20:02:21 -07:00
Kistaro Windrider	6efd05febe	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	2025-07-06 19:25:43 -07:00
Kistaro Windrider	383491fc5d	add load-bearing commas	2025-07-06 18:10:27 -07:00
Kistaro Windrider	8533720114	paths and segments are now factories instead the factory/instance deliniation is not clean but it _is_ efficient.	2025-07-06 18:09:56 -07:00
Kistaro Windrider	797818214a	fix lingering stuff from a previous iteration	2025-07-06 14:42:23 -07:00
Kistaro Windrider	ee24adf8b2	path prototype	2025-07-05 20:27:14 -07:00
Kistaro Windrider	0b98ee540d	segment prototype	2025-07-05 20:18:31 -07:00
Kistaro Windrider	9d02a1f570	destination prototype also ship bounds resets	2025-07-05 19:43:15 -07:00
Kistaro Windrider	c752e8e1e3	fix hpcols_init 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	2025-06-28 23:10:57 -07:00
Kistaro Windrider	507f06fb8c	more efficient bullet spawning	2025-06-28 22:59:51 -07:00
Kistaro Windrider	14849101dd	skip call to sparks if there are no sparks Then don't check for nil spark colors in sparks itself. Also uses a more verbose but more efficient exit check, and fixes a bug.	2025-06-28 22:49:10 -07:00
Kistaro Windrider	2cd7c64dd9	micro-optimize bullet details Shots that miss are most likely to not be there yet, so check Y-top first. If I assume shots will never be larger than 16 pixels per side, there is no reason to check the ship's genuine width and height.	2025-06-28 22:35:36 -07:00
Kistaro Windrider	2d5d392df0	reverse strip logic saves a single cycle per bullet, but...	2025-06-24 23:16:47 -07:00
Kistaro Windrider	904fbe6b2e	bullets don't expire	2025-06-24 23:06:09 -07:00
Kistaro Windrider	36b268e057	initialization is very slightly faster this way, I think	2025-06-24 22:54:03 -07:00
Kistaro Windrider	3d6ef03b37	attempt to optimize collision it's actually worse	2025-06-24 22:36:58 -07:00
Kistaro Windrider	d7e029edb6	profile-guided optimization	2025-06-23 01:37:57 -07:00
Kistaro Windrider	5e6b98523b	delete linked lists and use optimized array impls. Also removes "suppress" table from collider, use candidate.dead instead because the set of dead ships and the set of non-colliding ships is identical.	2025-06-23 00:47:02 -07:00
Kistaro Windrider	67970a5164	add draw/update stat readout surprisingly, update is most of my problem	2025-06-21 17:50:03 -07:00
Kistaro Windrider	eaea42f993	fix shot axis	2025-06-21 17:38:05 -07:00
Kistaro Windrider	929f47fc78	bullet microoptimization and velocity fix	2025-06-21 17:36:27 -07:00
Kistaro Windrider	430a0a4b14	ship_m:move micro-optimizations	2025-06-21 17:17:44 -07:00
Kistaro Windrider	e4062d3ccd	back out of fast bullet changes, keep optimizations in the "nothing but turrets" worst-case scenario, fast bullet logic costs 133% of slow bullet logic even when almost all shots on screen are slow. when I back out of this, that scenario is _still_ over 300% CPU but at least it's not 400%. note that this is with a screen mostly full of enemies, so processing all of them and their potential collisions also has cost, so the actual bullet-specific change is closer to 150%, maybe 200%. this is genuinely not as bad as I had thought but it doesn't feel like it will be workable; while my worst-case scenario is implausibly bad it's not actually 3x-likely-peak bad. so I'm going to need to find more optimizations, and probably give up on fast bullets. But I can keep the fast bullet branch around in case I find the headroom to reintroduce it later.	2025-06-21 17:05:36 -07:00
Kistaro Windrider	c9d7437ffe	trim up draw costs a bit	2025-06-21 16:40:23 -07:00
Kistaro Windrider	d0de757b0e	test the worst case scenario for shots way too slow	2025-06-21 16:36:36 -07:00
Kistaro Windrider	a8b5b9dbe6	fast shot rendering prototype it's slow and it sucks, and making it not suck will make it much slower. this is bad	2025-06-21 16:07:23 -07:00
Kistaro Windrider	2596f8aa6c	I can't spell	2025-06-21 15:13:07 -07:00
Kistaro Windrider	ef40c245f8	multi-step shot prototype nothing reaches this new logic yet, and multiple steps aren't drawn	2025-06-21 15:12:40 -07:00
Kistaro Windrider	6d6e13cf3b	special case strip(call_move) to stripmove() this gets called so much the extra function overhead actually seems bad	2025-06-21 14:55:20 -07:00
Kistaro Windrider	99323be298	despawn shots aggressively when offscreen avoids hitting enemies before they spawn in. may need to revisit this for the X coordinate if I want to implement a "Wild Ball" kind of weapon, but I think I won't have the tokens for that anyway	2025-06-20 19:13:28 -07:00
Kistaro Windrider	85c5091804	pbullets also move just before the collision check. This also sets up for the "fast shots" refactor.	2025-06-20 19:08:58 -07:00
Kistaro Windrider	a77180d89a	bullet_base:die doesn't actually make sense	2025-06-20 18:55:48 -07:00
Kistaro Windrider	c01c3400b7	fix eternal horizontal bullets	2025-06-20 18:51:58 -07:00
Kistaro Windrider	0f791b193c	more efficient collision iteration, fix eternal shots	2025-06-20 18:50:04 -07:00
Kistaro Windrider	d3351d9a05	Use eship_collider for ship collisions, too.	2025-06-20 17:56:57 -07:00
Kistaro Windrider	ecddb56d72	loops work better when you increment them	2025-06-20 17:50:03 -07:00
Kistaro Windrider	723c0f791c	Refactor collider to collaborate with linked_list. The only use of a collider is intertwined with the ship list, so I can combine the "prepare to yoink" and "populate collider" and "iterate list" steps, and I can combine the "hide" and "yoink" steps. This doesn't save tokens now but it's about to, when I use the eship collider to test pship collision.	2025-06-20 17:48:02 -07:00
Kistaro Windrider	e018578754	keep animating bullets while dead	2025-06-20 16:36:18 -07:00
Kistaro Windrider	bf8297eb72	prevify eships when setting up collider I will refactor this next: collider.new will take the linked list to ingest, perform the `insert` and "prevify" loops itself, then replace `hide` with `yoink`, which yoinks the item out of the original list. This pairs the `yoink` operation with the context that makes it possible to do (that is, the context when prevification was implemented); eships therefore cannot be edited in complex ways while the collider is still valid, but we can append to it as long as we don't expect those items to be procesesd correctly this frame. a new_eships+vore plan might be better if we turn out to need it, but presently we don't; flotilla spawning and raider spawning happen at a different point.	2025-06-20 16:31:18 -07:00
Kistaro Windrider	1c8bcae44c	put ebullet moves inside the collision check loop	2025-06-20 16:01:59 -07:00
Kistaro Windrider	325d7444e7	invert eship/pbullet collision Also mildly trims up linked_list impl.	2025-06-20 15:09:18 -07:00
Kistaro Windrider	789cdf6a7a	profile the drawing options	2025-06-08 17:36:50 -07:00
Kistaro Windrider	372133c15e	sqrt is actually faster	2025-06-08 16:55:15 -07:00
Kistaro Windrider	b38ebcc603	magnitest: cover image, png file	2025-06-08 16:16:16 -07:00
Kistaro Windrider	d9a10a7d07	fastest sqrt version, fix percentage	2025-06-08 16:14:18 -07:00
Kistaro Windrider	3ec786f416	fix deceleration	2025-06-08 15:11:36 -07:00
Kistaro Windrider	9955df6844	fix scaling alg	2025-06-08 15:11:07 -07:00
Kistaro Windrider	9e52e65ad1	fix font color	2025-06-08 15:10:12 -07:00
Kistaro Windrider	a9765bee1a	fix missed cls	2025-06-08 15:09:27 -07:00
Kistaro Windrider	b919eb824d	testing vector magnitude calculation	2025-06-08 15:08:58 -07:00
Kistaro Windrider	2c37784ad7	try this linefill func and start optimizing it	2025-06-08 14:35:49 -07:00
Kistaro Windrider	37d9e3d30e	more experiments with drawing these collision boxes. still sucks	2025-06-08 14:10:23 -07:00
Kistaro Windrider	1ef5b56c58	wait this version of zot actually looks good	2025-06-01 23:46:59 -07:00
Kistaro Windrider	44fb8482a5	a version of zot that does not look awful performance impact is probably not acceptable though	2025-06-01 23:29:03 -07:00
Kistaro Windrider	62f8f27829	a zot prototype that looks awful I need to draw all the hot parts last	2025-06-01 23:06:44 -07:00
Kistaro Windrider	542acc5308	nano-optimizations	2025-06-01 21:03:04 -07:00
Kistaro Windrider	4e66c875ad	improve legibility	2025-06-01 20:58:21 -07:00
Kistaro Windrider	812d32e70c	micro-optimizations	2025-06-01 20:58:12 -07:00
Kistaro Windrider	d2ec1b39df	Show approximation of contact zone	2025-06-01 20:38:56 -07:00
Kistaro Windrider	a3ac8074ae	line-box collision implemented by Pyrex&Nyeo	2025-06-01 20:29:02 -07:00
Kistaro Windrider	85d28ae28b	get rid of pships lots of things rely on exactly one primary ship now, so this was just overhead and wasted tokens / cspace.	2025-06-01 17:55:46 -07:00
Kistaro Windrider	c514c61b3a	look at me. look at me. I'm the gun_base now	2025-06-01 17:41:07 -07:00
Kistaro Windrider	9be828dd5c	blast gun is a trig gun now there are no more base guns	2025-06-01 17:38:45 -07:00
Kistaro Windrider	2b51a3472b	protron trig gun	2025-06-01 17:36:15 -07:00
Kistaro Windrider	95ea70baae	vulcan_gun as trig gun causes x offset to reverse for negative aim; may need to be careful with how I make aiming guns actually work, but this should work for deriving player guns from enemy guns (by using negative aim)!	2025-06-01 17:26:29 -07:00
Kistaro Windrider	b18b4f885d	trig zap gun; fixes use the trig gun for the zap gun	2025-06-01 17:00:28 -07:00
Kistaro Windrider	2fdb8d1a05	trigenometry gun prototype	2025-06-01 16:48:39 -07:00
Kistaro Windrider	fc1f84fa28	Delete slip behavior	2025-06-01 16:15:46 -07:00
Kistaro Windrider	93b63a5831	Prevent `new` calls that won't work as expected	2025-06-01 16:11:35 -07:00
Kistaro Windrider	297e6e4996	implement clip reload time two tiers of cooldowns, pretty much	2025-06-01 15:55:11 -07:00
Kistaro Windrider	9b3120c47b	rewrite mknew to inherit fields before init I am horrified to admit that C++'s constructor static initialization list syntax abruptly makes sense to me and I understand the problem it is trying to solve	2025-06-01 15:53:50 -07:00
Kistaro Windrider	abee6d1206	fix skirmisher sparks	2025-05-31 23:44:36 -07:00
Kistaro Windrider	3151db5430	fix precedence error	2025-05-31 22:27:03 -07:00
Kistaro Windrider	2964159858	fix offset, try but fail to fix variants	2025-05-31 22:19:35 -07:00
Kistaro Windrider	95d4b6eb37	what the hell was I thinking when I wrote this	2025-05-31 22:06:48 -07:00
Kistaro Windrider	96312e3adf	fix offset bugs	2025-05-31 22:05:47 -07:00
Kistaro Windrider	bf9a45d87e	fix gframe unit	2025-05-31 21:55:21 -07:00
Kistaro Windrider	36f7c6572f	fix ship spawning	2025-05-31 21:54:02 -07:00
Kistaro Windrider	45b70d3aca	did you know that 4 is not 1? mindboggling!	2025-05-31 21:43:51 -07:00
Kistaro Windrider	35980d801a	forgot my increments!	2025-05-31 21:40:17 -07:00
Kistaro Windrider	734811bd62	math works better when you return your values	2025-05-31 21:33:06 -07:00
Kistaro Windrider	4fddbea82c	use the right loader	2025-05-31 21:31:20 -07:00
Kistaro Windrider	f675e31967	oops, I accidentally	2025-05-31 21:30:30 -07:00
Kistaro Windrider	0bd1463416	replace demo level with infinite copies of flotilla 0	2025-05-31 21:29:54 -07:00
Kistaro Windrider	267f8a3667	actually add ships we keep	2025-05-31 21:02:26 -07:00
Kistaro Windrider	fa206c37c5	"redistribute"-type flotilla: update	2025-05-31 21:00:27 -07:00
Kistaro Windrider	928e7f7418	prototype flotilla loader	2025-05-31 20:39:07 -07:00
Kistaro Windrider	2439fda068	ship prototype tweaks	2025-05-31 20:38:59 -07:00
Kistaro Windrider	d13290f438	placeholder flotilla ships	2025-05-31 19:03:38 -07:00
Kistaro Windrider	e3a2810f0a	Prototype a flotilla template.	2025-05-25 21:03:51 -07:00
Kistaro Windrider	3764063b20	abandon "offset" sprites, use "row tier" sprites	2025-05-25 20:49:27 -07:00
Kistaro Windrider	90f6df2922	flotilla notes and sprites	2025-05-25 19:11:44 -07:00
Kistaro Windrider	b7c3e6ee92	adjust menu renderer	2025-05-03 17:26:48 -07:00
Kistaro Windrider	c91e5f4bd1	shorten RATE message not enough room to describe "fractions add up" -- maybe I can just fit in the "remainder" to hint that it will be considered in future upgrades?	2025-05-03 17:19:33 -07:00
Kistaro Windrider	ea2ddadb15	oops, method call syntax is special	2025-05-03 17:12:20 -07:00
Kistaro Windrider	9333c03bf3	add main gun rate upgrade to ship pool	2025-05-03 17:11:47 -07:00
Kistaro Windrider	1b45bd3dc3	fix rate formatting	2025-05-03 17:11:35 -07:00
Kistaro Windrider	71a7351d77	oops, miscalculated box width	2025-05-03 17:04:29 -07:00
Kistaro Windrider	80bb848468	options work better when I return them	2025-05-03 16:51:59 -07:00
Kistaro Windrider	b227844d12	Restyle ship stat upgrades.	2025-05-03 16:48:18 -07:00
Kistaro Windrider	ce14d03669	offer gun upgrades	2025-05-03 16:38:39 -07:00
Kistaro Windrider	ccd2c64103	update gun pick description style	2025-05-03 16:38:26 -07:00
Kistaro Windrider	e5b8a30cb6	cooldown reduction prototype I decided to keep cooldown in the same unit as the frame counter, because the extra math when calculating an upgrade is going to happen much less frequently than actual cooldown checks and calculations, so leaving the upgrade logic as the less efficient path seems like the more appropriate choice.	2025-05-03 16:28:54 -07:00
Kistaro Windrider	7ed305d2d9	Ammo quantity upgrade prototype Not yet tested. Will crash until I also get rate_upgrade_opt up.	2025-05-03 16:06:16 -07:00
Kistaro Windrider	288b7f64c8	tinker with blip colors, go back to level+1 with the current testing level, level + 1 is necessary to comfortably get a weapon before the Wall O' Block shows up	2025-01-26 22:32:17 -08:00
Kistaro Windrider	aea2a8c481	red blip when shield exhausted	2025-01-26 22:27:14 -08:00
Kistaro Windrider	9b24f10c23	inline ow, simplify blip, no shield piercing * any amount of shielding prevents all HP damage * when shields are sent to 0, orange blip * all blips are 3 frames considering a "shimmy" animation for start of shield recovery. maybe later	2025-01-26 22:25:06 -08:00
Kistaro Windrider	511c18f90e	remove offset when choosing category of upgrade	2025-01-26 22:15:03 -08:00
Kistaro Windrider	142810ee2d	scatter xp drops more	2025-01-26 22:11:02 -08:00
Kistaro Windrider	50beae1852	don't attract xp when dead	2025-01-26 22:08:16 -08:00
Kistaro Windrider	9c95fc1784	suck! suck! suck! suck! suck! suck! suck! suck!	2025-01-26 21:00:39 -08:00
Kistaro Windrider	cb2d24c9d0	thrust performance is now also an option	2025-01-26 20:38:31 -08:00
Kistaro Windrider	67603f8496	start of normal ship upgrades todo: thrust upgrade	2025-01-26 20:21:06 -08:00
Kistaro Windrider	2cebea663f	make stat modifications actually work	2025-01-26 13:14:59 -08:00
Kistaro Windrider	eed7b6af87	unique bullet base instances peel off new copies of ammo when using a new gun so we can upgrade it without screwing up the base stats	2025-01-26 13:07:43 -08:00