profile the drawing options

performance impact is probably not acceptable though

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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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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old_readme.md

@@ -0,0 +1,356 @@
+This file contains text that used to be in the cartridge itself, but
+I'm getting increasingly anxious about cartridge space so I'm moving
+it out ot a separate file.
+
+---
+
+main loop sequence
+==================
+1. level_frame
+2. events
+3. merge new_events into events
+4. update bg intangibles
+5. move ships (player first)
+6. move bullets (player first)
+7. calculate collisions
+ 1. pship on eship
+ 2. ebullet on pship
+ 3. pbullet on eship
+8. update fg intangibles
+9. check for end of level
+
+draw order
+----------
+bottom to top:
+1. intangibles_bg
+2. player bullets
+3. player ships
+4. enemy ships
+5. enemy bullets
+6. intangibles_fg
+
+notes
+-----
+intangibles_fg move()s after
+all collisions and other moves
+are processed. if an intangible
+is added to the list as a result
+of a collision or move, it will
+itself be move()d before it is
+drawn.
+
+data-driven items
+=================
+guns and bullets both allow the
+most common behaviors to be
+expressed with data alone.
+ships only need a movement
+algorithm expressed.
+
+guns
+----
+* t - metatable for bullet type.
+  fired once in the bullet's
+  default direction per shot.
+* enemy - if true, fired bullets
+  are flagged as enemy bullets.
+* icon - sprite index of an
+  8x8 sprite to display in the
+  hud when the player has this
+  gun. default is 20, a generic
+  crosshair bullseye thing.
+* cooldown - min frames between
+  shots.
+* ammo, maxammo - permitted
+  number of shots. 0 is empty
+  and unfireable. maxammo = 0
+  will cause a divide by zero
+  so don't do that. if nil,
+  ammo is infinite.
+
+default guns manage ammo and
+cooldown in shoot, then call
+actually_shoot to create the
+projectile. override only
+actually_shoot to change
+projectile logic while keeping
+cooldown and ammo logic.
+
+bullets
+-------
+* dx, dy - movement per frame.
+  player bullets use -dy
+  instead.
+* enemyspd - multiplier for dx
+  and dy on enemy bullets.
+  default is 0.5, making enemy
+  shots much easier to dodge
+* damage - damage per hit;
+  used by ships
+* sprite - sprite index.
+* x_off, y_off - renamed for
+  the next two vars. may revert
+* center_off_x - the horizontal
+  centerpoint of the bullet,
+  for positioning when firing.
+  assume a pixel's coordinates
+  refer to the upper left corner
+  of the pixel; the center of
+  a 2-width bullet with an
+  upper left corner at 0 is 1,
+  not 0.5.
+* top_off_y, bottom_off_y -
+  also for positioning when
+  firing. positive distance from
+  top or bottom edge to image.
+  top_off_y will usually be 0,
+  bottom_off_y will not be when
+  bullets are smaller than
+  the sprite box.
+* width, height - measured in
+  full sprites (8x8 boxes), not
+  pixels. used for drawing.
+
+bullets despawn when above or
+below the screen (player or
+enemy bullets, respectively).
+
+by default, bullets despawn
+when they hit something.
+override hitship to change this.
+
+ships
+____
+
+ships move by calculating
+momentum, then offsetting their
+position by that momentum, then
+clamping their position to the
+screen (horizontally only for
+ships that autoscroll). ships
+that autoscroll (slip==true)
+then slide down by scrollspeed.
+fractional coordinates are ok.
+after movement, ships lose
+momentum (ship.drag along each
+axis). abs(momentum) can't
+exceed ship.maxspeed.
+
+ships gain momentum by acting
+like a player pushing buttons.
+the player ship actually reads
+buttons for this.
+
+act -- returns new acceleration:
+dx, dy, shoot_spec, shoot_main.
+dx and dy are change in momentum
+in px/frame. this is controls
+only -- friction is handled in
+ship:move (`drag` value).
+
+ships hitting another ship take
+1 damage per frame of overlap.
+ships hitting a bullet check
+bullet.damage to find out how
+much damage they take. damage
+is applied to shields, then hp.
+damaged ships flash briefly -
+blue (12) if all damage was
+shielded, white (7) if hp was
+damaged. a ship that then has 0
+or less hp calls self:die() and
+tells the main game loop to
+remove it.
+
+shieldcooldown is the interval
+between restoring shield points.
+shieldpenalty is the delay
+before restoring points after
+any damage, reset to this value
+on every damaging hit (whether
+it is absorbed by the shield or
+not) -- shield behaves like
+halo and other shooters in its
+heritage, where it recovers if
+you avoid damage for a while.
+not that there is any safe cover
+in this kind of game.
+
+ships do not repair hp on their
+own. negative-damage bullets
+are treated as 0, but a bullet
+can choose to repair the ship
+it hits in its own hitship
+method, or otherwise edit it
+(changing weapons, refilling
+weapon ammo). powerups are
+therefore a kind of bullet.
+
+levels
+======
+
+a level is a table mapping
+effective frame number to
+functions. when a level starts,
+it sets lframe ("level frame")
+and distance to 0.
+
+every frame, level_frame
+increments lframe by 0x0.0001.
+then if the level is not frozen,
+it increments distance by 1.0
+and runs the function in the
+level table for exactly that
+frame number (if any). distance
+is therefore "nonfrozen frames",
+and is used to trigger level
+progress. lframe always
+increments. ships are encouraged
+to use lframe to control
+animation and movement, and may
+use distance to react to level
+progress separately from overall
+time. remember to multiply
+lframe-related stuff by 0x0001.
+
+a special sentinel value, eol,
+marks the end of the level.
+(the level engine doesn't know
+when it's out of events, so
+without eol, the level will
+simply have no events forever.)
+when it finds eol, level_frame
+throws away the current level
+and tells the main loop that it
+might be done. the main loop
+agrees the level is over and the
+player has won when the level
+has reached eol and there are
+no more enemy ships, enemy
+bullets, or background events
+remaining. player ships, player
+bullets, and intangibles are
+not counted.
+
+level freezing
+--------------
+the level is frozen when the
+global value freeze > 0.
+generally, something intending
+to block level progress (a
+miniboss, a minigame, etc.)
+increments freeze and prepares
+some means of decrementing it
+when it no longer wants to block
+level progress.
+
+most commonly, we want to block
+until some specific ship or
+group of ships has died. for
+these ships, override ship:die
+to decrement freeze. make sure
+to set ship.dead in any new
+ship:die method so anything else
+looking at it can recognize
+the ship as dead.
+
+for anything else, you probably
+want an event to figure out when
+to unfreeze.
+
+levels start at 1
+-----------------
+
+distance is initialized to 0
+but gets incremented before the
+first time the engine looks for
+events. therefore, the first
+frame of the level executes
+level[1]. since levelframe
+executes before anything else,
+level[1] sets up the first frame
+drawn in the level. the player
+does not see a blank world
+before level[1] runs.
+level[1] can therefore be used
+to reconfigure the player ship,
+set up backgrounds, start music,
+kick off some kind of fade-in
+animation, etc.
+
+
+events
+======
+the global list "events" stores
+0-argument functions which are
+called every frame. if they
+return true, they are removed
+from the list and not run again;
+if they return false, they stay
+and will be called in later
+frames. the level does not end
+while the events table is
+nonempty.
+
+events are most commonly used
+to set up something for later
+(for example, blip uses an event
+to remove the fx_pallete from
+the flashing ship when the blip
+expires), but can also be used
+to implement a "level within a
+level" that does something
+complicated until it's done. if
+you froze the level when
+creating the event, remember
+to thaw it (freeze -= 1) on all
+paths that return true.
+
+to do complex stuff in events,
+use a closure or a metatable
+that specifies __call.
+
+to avoid editing the events
+list while it is being iterated,
+events that create new events
+must add those events to
+new_events rather than events.
+new_events is only valid during
+the "event execution" stage, so
+events created at any other time
+must go directly on events
+without using new_events.
+
+intangibles
+===========
+
+the intangibles_fg and
+intangibles_bg lists contain
+items with :move and :draw.
+like ships and bullets, they
+move during _update60 and
+draw during _draw. they are
+not checked for collisions.
+
+intangibles_bg moves/draws
+before anything else moves or
+draws. intangibles_fg
+moves/draws last. this controls
+whether your intangible object
+draws in front of or behind
+other stuff. you probably want
+intangibles_bg for decorative
+elements and intangibles_fg
+for explosions, score popups,
+etc.
+
+there's no scrolling background
+engine but intangibles_bg could
+be used to create one, including
+using the map (otherwise unused
+in this engine) for the purpose.
+
+intangibles do not prevent the
+level from ending. like bullets
+and ships, if :move returns
+true, they are dropped.

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

rearm_prototype.p8

@@ -0,0 +1,223 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+-- vacuum gambit
+-- by kistaro windrider
+
+-- stdlib
+
+-- generate standard "overlay"
+-- constructor for type tt.
+-- if tt.init is defined, generated
+-- new calls tt.init(ret) after
+-- ret is definitely not nil,
+-- before calling setmetatable.
+-- use to initialize mutables.
+--
+-- if there was a previous new,
+-- it is invoked on the new
+-- object *after* more, because
+-- this works better with the
+-- `more` impls i use.
+function mknew(tt)
+ local mt,oldnew,more = {__index=tt},tt.new,rawget(tt, "init")
+ tt.new=function(ret)
+  if(not ret) ret = {}
+  if(more) more(ret)
+  if(oldnew) oldnew(ret)
+  setmetatable(ret, mt)
+  return ret
+ end
+ return tt
+end
+
+function easeoutbounce(t)
+	local n1=7.5625
+	local d1=2.75
+
+	if (t<1/d1) then
+		return n1*t*t;
+	elseif(t<2/d1) then
+		t-=1.5/d1
+		return n1*t*t+.75;
+	elseif(t<2.5/d1) then
+		t-=2.25/d1
+		return n1*t*t+.9375;
+	else
+		t-=2.625/d1
+		return n1*t*t+.984375;
+	end
+end
+
+-->8
+-- entry points
+function _draw()
+ cls()
+ draw_hud_placeholder()
+ left_pane:draw()
+ right_pane:draw()
+ rearm_pane_instance:draw()
+end
+
+function _init()
+ item=1
+ bfm=1
+ crt_frm = 1
+ left_pane = weapon_pane.new{}
+ right_pane = weapon_pane.new{
+  is_left=false,
+  s = 2,
+  hdr = "vulc",
+  body = "   rate\n\n  faster\n  firing\n   rate",
+  hot = function() return item == 2 end}
+ rearm_pane_instance = rearm_pane.new{hot=function() return item < 0 end}
+end
+
+function _update60()
+ crt_frm += 0.25
+ if (crt_frm >= 9) crt_frm = 1
+ if (btn(3) and item > 0 or btn(2) and item < 0) item = -item
+ if (btn(0)) item = 1
+ if (btn(1)) item = 2
+ if (btn() & 0xF ~= 0) and bfm >= 10 or bfm >= 30 then
+  bfm = 1
+ else
+  bfm += 1
+ end
+
+ if btnp(4) then
+  left_pane.pos = -1
+  right_pane.pos = -1
+  rearm_pane_instance.pos = -1
+ end
+
+ if btnp(5) then 
+  left_pane.pos = 1
+  right_pane.pos = 1
+  rearm_pane_instance.pos = 1
+ end
+
+ left_pane:update()
+ right_pane:update()
+ rearm_pane_instance:update()
+end
+
+function draw_hud_placeholder()
+ rectfill(112, 0, 127, 127,0x56)
+ rect(112,0,127,127,7)
+ line(127,1,127,127,5)
+ line(113,127)
+end
+
+-->8
+-- rearm pane drawing
+
+crt={-91,-166,-2641,-1441,-23041,23295,-20491,24570}
+
+function glow_box(x0, y0, x1, y1, c, cf)
+ for i,v in ipairs{c[1],c[2],c[1],0} do
+  i -= 1
+  rect(x0+i,y0+i,x1-i,y1-i,v)
+ end
+ fillp(crt[crt_frm&0xff])
+ rectfill(x0+4, y0+4, x1-4, y1-4, cf)
+ fillp()
+end
+
+function frame_col(hot)
+ if (not hot) return {4,10}
+ if (bfm<=16) return {14,7}
+ return {2,8}
+end
+
+function draw_weap_opt(x, y, c, s, hdr, body)
+ camera(-x,-y)
+ glow_box(0,0,55,100,c,1)
+ spr(s,5, 5)
+ print(hdr, 13, 8, 7)
+ print(body, 5, 15, 6)
+ camera()
+end
+
+function draw_rearm(c)
+ glow_box(0,101,111,127,c,1)
+ spr(5,15,107,4,2)
+ print("full ammo\nfull shield\n+50% health",54, 106, 6)
+end
+
+-->8
+-- rearm pane objects
+easing_pane = mknew{
+ -- to enter: pos = -1; to exit: pos = 1
+ -- runs for 32 frames in, 16 frames out
+}
+
+function easing_pane:frac()
+ local pos = self.pos
+ if (not pos) return
+ if (pos < 0) return 1-easeoutbounce(1+pos)
+ if (pos > 0) return (1-pos)*(1-pos)
+ return 0
+end
+
+function easing_pane:update()
+ local pos = self.pos
+ if (not pos or pos == 0) return
+ if (pos < 0) pos = min(pos + 0x0.05, 0)
+ if pos > 0 then
+  pos -= 0x0.1
+  if (pos <= 0) pos = nil
+ end
+ self.pos = pos
+end
+
+weapon_pane = mknew(easing_pane.new{
+ is_left = true,
+ s = 1,
+ hdr = "hull",
+ body = "\n    +1\n   max\n  health",
+ hot = function() return item == 1 end,
+})
+
+function weapon_pane:draw()
+ local frac, is_left = self:frac(), self.is_left
+ if (not frac) return
+ camera(
+  frac * (is_left and 55 or -128) + (1-frac) * (is_left and 0 or -56),
+  0)
+ glow_box(0,0,55,100,frame_col(self:hot()),1)
+ spr(self.s,5, 5)
+ print(self.hdr, 13, 8, 7)
+ print(self.body, 5, 15, 6)
+ camera()
+end
+
+rearm_pane = mknew(easing_pane.new{})
+
+function rearm_pane:draw()
+ local frac = self:frac()
+ if (not frac) return
+ camera(0, -28 * frac)
+ glow_box(0,101,111,127,frame_col(self:hot()),1)
+ spr(5,15,107,4,2)
+ print("full ammo\nfull shield\n+50% health",54, 106, 6)
+ camera()
+end
+
+__gfx__
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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.
+
+__gfx__
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