adjust menu renderer

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?

.gitignore

@@ -0,0 +1,2 @@
+.DS_Store
+.vscode/settings.json

autobrake_test.p8

@@ -0,0 +1,244 @@
+pico-8 cartridge // http://www.pico-8.com
+version 41
+__lua__
+
+-- vacuum gambit automatic brake test
+-- by kistaro windrider
+
+function usplit(str)
+ return unpack(split(str))
+end
+function csv(s)
+ local ret = split(s, "\n")
+ for i, v in ipairs(ret) do
+  ret[i] = type(v) == "string" and split(v) or { v }
+ end
+ return ret
+end
+
+-- generate standard "overlay"
+-- constructor for type tt.
+-- if more is defined, generated
+-- new calls more(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, more)
+ local mt, oldnew = { __index = tt }, tt.new
+ tt.new = function(ret)
+  if (not ret) ret = {}
+  if (more) more(ret)
+  if (oldnew) oldnew(ret)
+  setmetatable(ret, mt)
+  return ret
+ end
+end
+
+function _init()
+ pal(1,129,1)
+ the_ship = ship.new()
+ constraints:setup()
+ slomo = 1
+ sloc = 0
+ reroll()
+end
+
+function reroll()
+ frames=0
+ sloc=0
+ the_ship:reroll()
+end
+
+function _update60()
+ if (btnp(4)) reroll()
+ if (btnp(5)) constraints:cycle()
+ if (btnp(3)) slomo <<= 1
+ if (btnp(2)) slomo >>= 1
+ slomo = (slomo < 1) and 1 or (slomo > 8192) and 8192 or slomo
+ sloc += 1
+ if sloc >= slomo then
+  frames += 1
+  the_ship:update()
+  sloc=0
+ end
+end
+
+function _draw()
+ cls(1)
+ constraints:draw()
+ the_ship:draw()
+ print("frames: " .. frames, 4, 64, 7)
+ print("speed: 1/" .. slomo, 8, 70, 7)
+
+ print("thrust: ".. actual_t, 4, 80, 7)
+ meter(80, 80, 128, 84, actual_t/the_ship.thrust/2)
+ print("dx: ".. the_ship.dx, 20, 86, 7)
+ meter(80, 86, 128, 90, the_ship.dx/the_ship.maxspd/2)
+ print("x: "..the_ship.x, 24, 92, 7)
+ print("bx: "..gbx, 20, 98, 7)
+
+ print("xmin:"..tostr(constraints.xmin), 12, 108, 7)
+ print("xmax:"..tostr(constraints.xmax), 12, 114, 7)
+end
+
+function meter(x0, y0, x1, y1, frac)
+ local c = 11
+ if frac < 0 then
+  frac = -frac
+  c = 8
+ end
+ local range = x1-x0
+ local midpoint = x0 + (range/2)
+ rectfill(x0, y0-1, x0, y1+1, 13)
+ rectfill(midpoint, y0-1, midpoint, y1 + 1, 13)
+ local width = range * frac
+ if (width ~= 0) rectfill(x0, y0, x0 + width, y1, c)
+end
+
+-->8
+-- ship
+
+ship = {
+ maxspd=4,
+ thrust=0.25,
+ drag=0.0625,
+ y=32,
+}
+mknew(ship)
+
+function ship:reroll()
+ self.x=rnd(128)
+ self.dx=rnd(2*self.maxspd)-self.maxspd
+end
+
+function ship:draw()
+ if self.x < -7 then
+  spr(2, 0, self.y-7)
+  spr(2, 0, self.y+8)
+ elseif self.x > 127 then
+  spr(2, 120, self.y-7, 1, 1, true)
+  spr(2, 120, self.y+8, 1, 1, true)
+ else
+  spr(1,self.x,self.y)
+ end
+
+ --if (self.dx == 0) return
+ local bd, f = brake_dist(self.dx, self.thrust + self.drag)
+ gbx = self.x+bd
+ spr(3, gbx-2,self.y-2)
+ print(tostr(f), gbx-2, self.y - 8, 14)
+end
+
+function calc_velocity(v0, t, vmax, drag)
+ v0 = mid(v0 + t, vmax, -vmax)
+ return v0 - mid(drag, -drag, v0)
+end
+
+function ship:update()
+ local t = btn(0) and -1 or btn(1) and 1 or 0
+ t *= self.thrust
+ t = constraints:constrain(self, t)
+ -- t = constraints:constrain(self, t)
+ -- t = constraints:constrain(self, t)
+ local s = calc_velocity(self.dx, t, self.maxspd, self.drag)
+
+ self.x += s
+ self.dx = s
+ actual_t = t
+end
+
+-->8
+-- constraints
+
+constraints = {
+ ymin=20,
+ ymax=52,
+ color=10
+}
+
+function constraints:constrain(s, want)
+ self.color=10
+ if (not self.xmin) return want
+
+ -- bmx: brake max
+ local v1, bmx = calc_velocity(s.dx, want, s.maxspd, s.drag), s.thrust + s.drag
+ local bd, bf = brake_dist(v1, bmx)
+ local bx, txm = s.x + bd + v1, self.xmax
+ if bx < self.xmin then
+  -- predicted brake point left
+  -- of xmin; apply max reverse
+  -- thrust, treat xmin as our
+  -- max target, and handle
+  -- overbraking by coalescing
+  -- with past +xmax case
+  self.color = 9
+  want = s.thrust
+  txm = self.xmin
+  v1 = calc_velocity(s.dx, want, s.maxspd, s.drag)
+  bd, bf = brake_dist(v1, bmx)
+  bx  = bd + s.x + v1
+ end
+ if (bx <= txm) return want
+ self.color = 8
+ local overage = bx - txm
+ want -= overage/max(bf,1)
+ if (want < -s.thrust) want = -s.thrust
+ return want
+end
+
+function brake_dist(v0, brake_max)
+ local tri_frames = abs(v0\brake_max)
+ local chunks = tri_frames * (tri_frames - 1) >> 1
+ local chunk_zone = chunks * brake_max
+ local overage = abs(v0) - tri_frames * brake_max
+ return (chunk_zone + overage * (tri_frames + 1)) * sgn(v0), (overage > 0) and tri_frames + 1 or tri_frames
+end
+
+function constraints:cycle()
+ if self.ctype=="bounds" then
+  self.ctype="point"
+ elseif self.ctype=="point" then
+  self.ctype="off"
+ else
+  self.ctype="bounds"
+ end
+ self:setup()
+end
+
+function constraints:setup()
+ if self.ctype=="point" then
+  self.xmin = 64
+  self.xmax = 64
+ elseif self.ctype=="bounds" then
+  self.xmin = 32
+  self.xmax = 96
+ else
+  self.xmin = nil
+  self.xmax = nil
+ end
+end
+
+function constraints:draw()
+ if (not self.xmin) return
+ rect(self.xmin, self.ymin, self.xmax, self.ymax, self.color)
+end
+
+-->8
+-- fx
+
+-- todo: spark ring buffer
+
+__gfx__
+000000008000000000080000a000a000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000006666000080000009090000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000067777600800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000675555758008888009090000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+000000006750007508000000a000a000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000067777500080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000005555000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

code-of-conduct.md

@@ -0,0 +1 @@
+Trans rights.

genericshmup.p8

@@ -0,0 +1,945 @@
+pico-8 cartridge // http://www.pico-8.com
+version 34
+__lua__
+-- generic shmup
+-- by kistaro windrider
+
+game = 1
+win = 2
+lose = 3
+
+debug = {}
+
+function _init()
+-- create the pwr gradient
+-- 15 is the gradient color
+ poke(0x5f5f,0x3f)
+ poke(0x5f68,10)
+ poke(0x5f69,10)
+ poke(0x5f6a,9)
+ poke(0x5f6b,4)
+ memset(0x5f78,0xa8,3)
+ init_bullet_mt()
+ init_ship_mt()
+	wipe_level()
+	primary_ship.special_gun = new_gun_of(blast_gun_t)
+	load_level(example_level)
+	state = game
+end
+
+function wipe_level()
+ primary_ship = new_p1()
+ pships = {primary_ship}
+ eships = {}
+ pbullets = {}
+ ebullets = {}
+ intangibles = {}
+ events = {}
+end
+
+function _update60()
+ if (state == game) updategame()
+end
+
+function updategame()
+ local leveldone = level_frame()
+	local deaths = {}
+	for i, e in ipairs(events) do
+	 if (e()) add(deaths, i)
+	end
+	bury_the_dead(events, deaths)
+ for _, tbl in ipairs({pships, eships, pbullets, ebullets, intangibles}) do
+	 local deaths = {}
+	 for i, x in ipairs(tbl) do
+	  if (x:move()) add(deaths, i)
+	 end
+	 bury_the_dead(tbl, deaths)
+	end
+	--then, calculate collisions
+	local pdeaths = {}
+	local edeaths = {}
+	for ip, ps in ipairs(pships) do
+	 for ie, es in ipairs(eships) do
+	  if collides(hurtbox(ps), hurtbox(es)) then
+	   if (es:hitship(ps)) add(edeaths, ie)
+	   if ps:hitship(es) then
+	    add(pdeaths, ip)
+	    break
+	   end
+	  end
+	 end
+	end
+	bury_the_dead(pships, pdeaths)
+	bury_the_dead(eships, edeaths)
+	pdeaths = {}
+	edeaths = {}
+	for ip, ps in ipairs(pships) do
+	 for ie, eb in ipairs(ebullets) do
+	  if collides(hurtbox(ps), hurtbox(eb)) then
+	   if (eb:hitship(ps)) add(edeaths, ie)
+	   if ps:hitbullet(eb) then
+	    add(pdeaths, ip)
+	    break
+	   end
+	  end
+	 end
+	end
+	bury_the_dead(pships, pdeaths)
+	bury_the_dead(ebullets, edeaths)
+	pdeaths = {}
+	edeaths = {}
+	for ip, pb in ipairs(pbullets) do
+	 for ie, es in ipairs(eships) do
+	  if collides(hurtbox(pb), hurtbox(es)) then
+	   if (es:hitbullet(pb)) add(edeaths, ie)
+	   if pb:hitship(es) then
+	    add(pdeaths, ip)
+					break
+				end
+	  end
+	 end
+	end
+	bury_the_dead(eships, edeaths)
+	bury_the_dead(pbullets, pdeaths)
+	
+	if leveldone and ((#eships + #ebullets + #events) == 0) then
+	  state = win
+	end
+	if #pships == 0 then
+	  state = lose
+	end
+end
+
+function _draw()
+ drawgame()
+ draw_debug()
+ if (state == win) dropshadow("win",50,61,11)
+ if (state == lose) dropshadow("fail",48,61,8)
+end
+
+function draw_debug()
+ if (#debug==0) return
+ cursor(0,0,7)
+ foreach(debug,print)
+ debug={}
+end
+
+function drawgame()
+ cls()
+ clip(0,0,112,128)
+ for tbl in all{pbullets, pships, eships, intangibles, ebullets} do
+  for x in all(tbl) do
+   x:draw()
+  end
+ end
+ clip(0,0,128,128)
+ drawhud()
+end
+
+function drawhud()
+ -- 112-and-right is hud zone
+ rectfill(112, 0, 127, 127,0x56)
+ rect(112,0,127,127,7)
+ line(127,1,127,127,5)
+ line(113,127)
+ 
+ draw_gun_info("❎",116,3,primary_ship.main_gun)
+ draw_gun_info("🅾️",116,31,primary_ship.special_gun)
+ 
+ dropshadow("pwr",114,59,1)
+ inset(114,66,125,92)
+ vertmeter(115,67,124,91,primary_ship.power, primary_ship.max_power, 15)
+ 
+ dropshadow("h s",114,97,1)
+ inset(114,104,125,125)
+ line(119,105,119,124,7)
+ line(120,105,120,125,5)
+ vertmeter(115,105,118,124,primary_ship.hp, primary_ship.maxhp, 8)
+ vertmeter(121,105,124,124,primary_ship.shield, primary_ship.maxshield,12)
+end
+
+function draw_gun_info(lbl,x,y,gun)
+ dropshadow(lbl,x,y,1)
+ inset(114,y+7,125,y+18)
+ inset(114,y+20,125,y+24)
+ if(gun) then
+  spr(gun.icon,116,y+9,1,1)
+  --115 to 124 - ammo bar. round up
+  if gun.ammo == nil then
+   fillp(0xa5a5)
+   rectfill(115,y+21,124,y+23,0xea)
+   fillp(0)
+  elseif gun.ammo > 0 then
+   rectfill(
+     115,y+21,
+     115+flr(9*gun.ammo/gun.maxammo),
+     y+23,10)
+  else
+   line(118, y+22, 121, y+22, 2)
+  end
+ end
+end
+
+function vertmeter(x0,y0,x1,y1,val,maxval,col)
+ if (val <= 0) return
+ local h = y1-y0
+ local pxm1 = flr(h*val/maxval)
+ rectfill(x0,y1-pxm1,x1,y1,col)
+end
+
+function inset(x0,y0,x1,y1)
+ rectfill(x0,y0,x1,y1,0)
+ rect(x0,y0,x1,y1,7)
+ line(x1,y0,x0,y0,5)
+ line(x0,y1,5)
+end
+
+function dropshadow(str, x, y, col)
+ print(str, x+1, y+1, 5)
+ print(str, x, y, col)
+end
+
+function grab_p1_butts()
+ 
+ local b = btn()
+ return {
+  [0]=b&0x1,
+  [1]=(b&0x2)>>1,
+  [2]=(b&0x4)>>2,
+  [3]=(b&0x8)>>3,
+  [4]=(b&0x10)>>4,
+  [5]=(b&0x20)>>5
+ }
+end
+
+function bury_the_dead(tbl, dead)
+ if (#dead == 0) return
+ local tail = dead[1]
+ local head = tail + 1
+ local deaddex = 2
+ 
+ while head <= #tbl do
+  while deaddex <= #dead and head == dead[deaddex] do
+   deaddex += 1
+   head += 1
+  end
+  if (head > #tbl) break
+  tbl[tail] = tbl[head] 
+  head += 1
+  tail += 1
+ end
+ 
+ for i=1,(head-tail) do
+  deli(tbl)
+ end
+end
+-->8
+--ships, including player
+
+function init_ship_mt()
+ setmetatable(player, ship_t)
+ setmetatable(frownie, ship_t)
+ setmetatable(blocky, frownie_t)
+end
+
+player = {
+ --shape
+ sprite = 1, --index of ship sprite
+ size = 2, --all ships are square; how many 8x8 sprites?
+ hurt = { -- hurtbox - where this ship can be hit
+  x_off = 6, -- upper left corner
+  y_off = 6, -- relative to ship ulc
+  width = 4,
+  height = 4
+ },
+ 
+ -- health and power
+ hp = 3, -- current health, non-regenerating
+ maxhp = 3, -- player only; other ships never heal
+ shield = 2, -- regenerates, using power
+ maxshield = 2,
+ shieldcost = 300, -- power cost to refill shield
+ generator = 1.5,  -- 1 feels too slow
+
+ -- gun
+ main_gun = nil, -- assign at spawn time
+ special_gun = nil,
+ fire_off_x = 8,  -- offset where bullets come from
+ fire_off_y = 0,
+
+ -- position
+ x=52, -- x and y are for upper left corner
+ y=96,
+ xmomentum = 0,
+ ymomentum = 0,
+ maxspd = 2.5, -- momentum cap
+ thrust = 0.25, -- momentum added from button
+ drag = 0.125, -- momentum lost per frame
+ slip = false, -- does not slide down screen
+ grab_butts = grab_p1_butts, -- button fetch algorithm
+}
+
+player_t = {
+ __index = player
+}
+
+function new_p1()
+ p = {
+  main_gun = new_gun_of(zap_gun_t, false)
+ }
+ setmetatable(p, player_t)
+ return p
+end
+
+frownie = {
+ --shape
+ sprite = 3, --index of ship sprite
+ size = 1, --all ships are square; how many 8x8 sprites?
+ hurt = { -- hurtbox - where this ship can be hit
+  x_off = 1, -- upper left corner
+  y_off = 1, -- relative to ship ulc
+  width = 6,
+  height = 6
+ },
+ 
+ -- health and power
+ hp = 1, -- enemy ships need no max hp
+
+ -- position
+ x=60, -- x and y are for upper left corner
+ y=8,
+ xmomentum = 0,
+ ymomentum = 0,
+ maxspd = 2, -- momentum cap
+ thrust = 0.12, -- momentum added from button
+ drag = 0.07, -- momentum lost per frame
+ slip = true,
+ grab_butts = function(discard_self)
+  -- buttons are effectively analog
+  -- and negative buttons work just fine!
+  local butts = {}
+  local tstate = (1 + flr(4*t() + 0.5)) % 6
+  butts[0] = ((tstate==1 or tstate==2) and 1) or 0
+  butts[1] = ((tstate==4 or tstate==5) and 1) or 0
+  for b=2, 5 do
+   butts[b]=0
+  end
+  return butts
+ end, -- button fetch algorithm
+}
+frownie_t = {
+ __index = frownie
+}
+
+blocky = {
+ sprite = 10,
+ hp = 2,
+ ow = function(self)
+  if self.hp <= 1 then
+   self.sprite = 11
+  else
+   self.sprite = 10
+  end
+ end
+}
+
+blocky_t = {
+ __index = blocky
+}
+-->8
+--ship behavior
+
+scrollrate = 0.25 --in px/frame
+
+ship_m = {
+
+ -- ships have no shield by default
+ shield = 0,
+ maxshield = 0,
+ shieldcost = 32767.9,
+ shieldcooldown =  180,
+ 
+ -- default generator behavior:
+ -- 10 seconds for a full charge
+ max_power = 600,
+ power = 600,
+ generator = 1, -- power gen per frame
+
+ invincible_until = -32768,
+ 
+ slip = true  -- most enemies slide
+}
+
+ship_t = {
+  __index = ship_m,
+}
+
+function ship_m.die(_)
+end
+
+function ship_m.move(ship)
+ ship:refresh_shield()
+ ship.power = min(ship.max_power, ship.power + ship.generator)
+ butt = ship.grab_butts()
+ if (butt[5] > 0) ship:maybe_shoot(ship.main_gun)
+ if (butt[4] > 0) ship:maybe_shoot(ship.special_gun)
+ ship.xmomentum += (ship.thrust * butt[1]) - (ship.thrust * butt[0])
+ ship.ymomentum += (ship.thrust * butt[3]) - (ship.thrust * butt[2])
+ ship.xmomentum = mid(-ship.maxspd, ship.maxspd, ship.xmomentum)
+ ship.ymomentum = mid(-ship.maxspd, ship.maxspd, ship.ymomentum)
+
+ ship.x = mid(0, 112 - 8 * ship.size, ship.x + ship.xmomentum)
+ if not ship.slip then
+  ship.y = mid(0, 128 - 8 * ship.size, ship.y + ship.ymomentum)
+ end
+ 
+ --friction
+ local xfric = 0
+ local yfric = 0
+ if (ship.xmomentum > 0) xfric = min(ship.xmomentum, ship.drag)
+ if (ship.xmomentum < 0) xfric = max(ship.xmomentum, -ship.drag)
+ if (ship.ymomentum > 0) yfric = min(ship.ymomentum, ship.drag)
+ if (ship.ymomentum < 0) yfric = max(ship.ymomentum, -ship.drag)
+ ship.xmomentum -= xfric
+ ship.ymomentum -= yfric
+ 
+ -- "scrolling" behavior
+ if ship.slip then
+  ship.y += scrollrate
+  if ship.y >= 128 then
+   ship:die()
+   return true
+  end
+ end
+ return false
+end  -- moveship(ship)
+
+function ship_m.draw(ship)
+	spr(ship.sprite, ship.x, ship.y, ship.size, ship.size)
+end
+
+function hurtbox(ship)
+ return {
+  x=ship.x + ship.hurt.x_off,
+  y=ship.y + ship.hurt.y_off,
+  width=ship.hurt.width,
+  height=ship.hurt.height
+ }
+end
+
+function ship_m:maybe_shoot(gun)
+ if (not gun) return
+ if (self.power < gun.power) return
+ if (not gun:shoot(self.x + self.fire_off_x, self.y + self.fire_off_y)) return
+ self.power -= gun.power
+end
+
+function ship_m:hitship(other)
+ return self:hitsomething(1)
+end
+
+function ship_m:hitbullet(b)
+ return self:hitsomething(b.damage)
+end
+
+function ship_m:hitsomething(dmg)
+ if (dmg <= 0) return false
+ if (lframe < self.invincible_until) return false
+ self.shield_refresh_ready = lframe + self.shieldcooldown
+ if self.shield >= dmg then
+  self.shield -= dmg
+  self:ow()
+  return false
+ end	
+ dmg -= self.shield
+ self.shield = 0
+ self.hp -= dmg
+ if self.hp <= 0 then
+  self:die()
+  return true
+ end
+ self:ow()
+ return false
+end
+
+function ship_m:ow()
+ -- todo: implement damage blink
+end
+
+function ship_m:refresh_shield()
+ if (self.shield >= self.maxshield) return
+ if (lframe < self.shield_refresh_ready) return
+ if (self.power < self.shieldcost) return
+ self.shield += 1
+ self.power -= self.shieldcost
+ self.shield_refresh_ready = lframe + self.shieldcooldown
+end
+-->8
+-- collisions
+
+-- box: x, y, width, height
+
+function collides(box1, box2)
+	local dx = box2.x - box1.x
+	local cx = dx >= 0 and dx <= (box1.width or 0)
+	dx = box1.x - box2.x
+	cx = cx or (dx >= 0 and dx <= (box2.width or 0))
+	if (not cx) return false
+	
+	local dy = box2.y - box1.y
+	local cy = dy >= 0 and dy <= (box1.height or 0)
+	dy = box1.y - box2.y
+	cy = cy or (dy >= 0 and dy <= (box2.height or 0))
+	return cy
+end
+-->8
+-- level and event system
+
+-- a level is a map from
+-- effective frame number to
+-- callback for that frame.
+
+-- effective frame number stops
+-- when freeze count is nonzero
+
+-- a level is won when it hits
+-- the end-of-level sentinel 
+-- and there are no more
+-- tracked enemies.
+-- lost when there are no
+-- player ships left.
+
+-- effective frame
+distance = 0
+-- actual frame count since
+-- start of level
+lframe = 0
+
+-- do not advance distance when
+-- nonzero
+freeze = 0
+
+eol = {}
+
+function load_level(lvltbl)
+ distance = 0
+ lframe = 0
+ freeze = 0
+ current_level = {}
+ for frame, cb in pairs(lvltbl) do
+  current_level[frame] = cb
+ end
+end
+
+function level_frame()
+ lframe += 1
+ if (current_level == nil) return true
+ if freeze == 0 then 
+  distance += 1
+  local cb = current_level[distance]
+  if cb ~= nil then
+   if cb == eol then
+    current_level = nil
+    return true
+   else
+    cb()
+   end
+  end
+ end
+ return false
+end
+-->8
+-- example level
+
+function spawn_rnd_x(mt)
+ s = {
+  x = rnd(104),
+  y = -(mt.__index.size * 8 - 1)
+ }
+ setmetatable(s, mt)
+ add(eships, s)
+end
+
+function spawn_blocking_rnd_x(mt)
+ freeze += 1
+ s = {
+  x = rnd(104),
+  y = -7,
+  die = function(self)
+   freeze -= 1
+   mt.__index.die(self)
+  end
+ }
+ setmetatable(s, mt)
+ add(eships, s)
+end
+
+function spawn_frownie()
+ spawn_rnd_x(frownie_t)
+end
+
+function spawn_blocking_frownie()
+ spawn_blocking_rnd_x(frownie_t)
+end
+
+function spawn_blocky()
+ spawn_rnd_x(blocky_t)
+end
+
+function spawn_blocking_blocky()
+ spawn_blocking_rnd_x(blocky_t)
+end
+
+example_level = {
+ [1]=spawn_frownie,
+ [60]=spawn_blocky,
+ [61]=spawn_blocky,
+ [250]=spawn_blocking_blocky,
+ [310]=function()
+  spawn_blocking_blocky()
+  spawn_blocking_blocky()
+  spawn_blocking_blocky()
+ end,
+ [311]=spawn_frownie,
+ [401]=spawn_frownie,
+ [420]=spawn_blocking_frownie,
+ [450]=spawn_frownie,
+ [451]=eol
+}
+-->8
+-- bullets and guns
+
+function init_bullet_mt()
+ setmetatable(zap, bullet_t)
+ setmetatable(zap_gun, gun_t)
+ setmetatable(blast, bullet_t)
+ setmetatable(blast_gun, gun_t)
+end
+
+zap = {
+ --shape
+ psprite = 8, --index of player ammo sprite
+ esprite = 9, -- index of enemy ammo sprite
+ width = 1, --in 8x8 blocks
+ height = 1,
+ hurt = { -- hurtbox - where this ship can be hit
+  x_off = 0, -- upper left corner
+  y_off = 0, -- relative to sprite
+  width = 2,
+  height = 8
+ },
+ center_x_off = 1, -- how to position by ship
+ bottom_y_off = 0,
+ top_y_off = 0,
+ 
+ damage = 1,
+ dx = 0,  -- px/frame
+ dy = 8,
+
+ hitship = function(_, _)
+  return true
+ end
+}
+zap_t = {
+ __index = zap
+}
+
+zap_gun = {
+ enemy = false,
+ power = 30, -- power consumed per shot
+ cooldown = 10, -- frames between shots
+ ammo = nil, -- unlimited ammo - main gun
+ t = zap_t -- metatable of bullet to fire
+}
+
+zap_gun_t = {
+ __index = zap_gun
+}
+
+blast = {
+ --shape
+ psprite = 12, --index of player ammo sprite
+ esprite = 3, -- index of enemy ammo sprite
+ width = 1, --in 8x8 blocks
+ height = 1,
+ hurt = { -- hurtbox - where this ship can be hit
+  x_off = 1, -- upper left corner
+  y_off = 1, -- relative to sprite
+  width = 6,
+  height = 6
+ },
+ center_x_off = 4, -- how to position by ship
+ bottom_y_off = 0,
+ top_y_off = 0,
+ 
+ damage = 4,
+ dx = 0,  -- px/frame
+ dy = 2,
+
+ -- disable damage for 2 frames
+ -- when hitting something
+ hitship = function(self, _)
+  self.damage = 0
+  local wait = 2
+  e = function()
+   wait -= 1
+   if wait <= 0 then
+    self.damage = 4
+    return true
+   end
+   return false
+  end
+  add(events, e)
+ end
+}
+blast_t = {
+ __index = blast
+}
+
+blast_gun = {
+ icon = 13,
+ enemy = false,
+ power = 0, -- ammo, not power
+ cooldown = 30, -- frames between shots
+ ammo = 5,
+ maxammo = 5,
+ t = blast_t -- metatable of bullet to fire
+}
+
+blast_gun_t = {
+ __index = blast_gun
+}
+
+function new_gun_of(mt, is_enemy)
+ g = {
+  enemy = e
+ }
+ setmetatable(g, mt)
+ return g
+end
+-->8
+-- bullet and gun behaviors
+
+bullet_base = { }
+
+bullet_t = {
+ __index = bullet_base
+}
+
+gun_base = { 
+ shoot_ready = -32768,
+ 
+ icon = 20
+}
+
+gun_t = {
+ __index = gun_base
+}
+
+function bullet_base:hitship(_)
+ self:die()
+ return true
+end
+
+function bullet_base:die()
+end
+
+function bullet_base:move()
+ self.x += self.dx
+ if self.enemy then
+  self.y += self.dy
+  if self.y > 128 then
+   self:die()
+   return true
+  end
+ else
+  self.y -= self.dy
+  if self.y < -8*self.height then
+   self:die()
+   return true
+  end
+ end
+ return false
+end
+
+function bullet_base:draw()
+ spr(self.sprite, self.x, self.y, self.width, self.height)
+end
+
+function bullet_base:spawn_at(x, y)
+ self.x = x - self.center_x_off
+ if self.enemy then
+  self.y = y + self.top_y_off
+  add(ebullets, self)
+ else
+  self.y = y - (8 * self.height) + self.bottom_y_off
+  add(pbullets, self)
+ end
+end
+
+function gun_base:shoot(x, y)
+ if (lframe < self.shoot_ready) return false
+ if self.ammo then
+  if (self.ammo <= 0) return false
+  self.ammo -= 1
+ end
+ self.shoot_ready = lframe + self.cooldown
+ b = { }
+ setmetatable(b, self.t)
+ if self.enemy then
+  b.enemy = true
+  b.sprite = b.esprite
+ else
+  b.enemy = false
+  b.sprite = b.psprite
+ end
+ b:spawn_at(x, y)
+ return true
+end
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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.

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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+00000000bba80880000008000aa00aa00a0880a0447777700477777a000000000000000000000000000000000000000000000000000000000000000000000000
+007007000aaa28780a0000000990099008000080477aaa7a0477aaaa000000000000000000000000000000000000000000000000000000000000000000000000
+0007000008a8887808000000099009900080080047a0047a047a0000000000000000000000000000000000000000000000000000000000000000000000000000
+00007000088888820000a000088008800000000047a0447a047a0000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700008888200000800008800880a000000a47a4477a047a4440000000000000000000000000000000000000000000000000000000000000000000000000
+000000000008820000a0000008800880080aa080477777a00477777a000000000000000000000000000000000000000000000000000000000000000000000000
+0000000000002000008000000880088000088000477770000422aaaa222200020000020000000000000000000000000000000000000000000000000000000000
+0d5000000000000000000000000000000000000047a77700022ee0002eeee002e00022e000000000000000000000000000000000000000000000000000000000
+d00000000000000000000000000000000000000047a4777002ea2e002e002e02ee022ee000000000000000000000000000000000000000000000000000000000
+500000000000000000000000000000000000000047a0477a22ea2e002e002e02e2e2e2e000000000000000000000000000000000000000000000000000000000
+000000000000000000000000000000000000000047a0047a2e2222e02e222e02e02e02e000000000000000000000000000000000000000000000000000000000
+000000000000000000000000000000000000000047a0047a2eeeeeea2eeee002e02e02e000000000000000000000000000000000000000000000000000000000
+00000000000000000000000000000000000000000aa000aa2e7aa2ea2e00e002e02e02e000000000000000000000000000000000000000000000000000000000
+0000000000000000000000000000000000000000000000002e0002e02e002e02e02e02e000000000000000000000000000000000000000000000000000000000
+0000000000000000000000000000000000000000000000000e0000e00e000e00e00e00e000000000000000000000000000000000000000000000000000000000

the_parser.p8

@@ -0,0 +1,61 @@
+pico-8 cartridge // http://www.pico-8.com
+version 41
+__lua__
+-- the parser
+
+parser = {}
+mknew(parser)
+
+-- calls parse_into with a nop
+-- emit function.
+function parser:parse(str)
+ self:parse_into(str, function() end)
+end
+
+-- read a file of commands and
+-- execute them, emitting the
+-- results from each call into
+-- `emit` as a table per row.
+--
+-- a "command" is a method on
+-- self. a row alternates
+-- commands with args. when
+-- calling a command, it also
+-- gets a table of previous
+-- results as the first arg.
+-- args are split on ','.
+function parser:parse_into(str, emit)
+ for row in all(split(str, "\n")) do
+  local prev = {}
+  local sectors = split(row, ":")
+  for i=1,#sectors,2 do
+   local x = self[sectors[i]](self, prev, usplit(sectors[i+1]))
+   if (x) add(prev, x)
+  end
+  emit(prev)
+ end
+end
+
+-- saves prev[sel] as self.name.
+-- if sel is unspecified, saves
+-- all of prev (as a table).
+function parser:saveas(prev, name, sel)
+ self[name] = sel and prev[sel] or prev
+end
+
+-- returns its args, ignoring
+-- prev. Used to stuff things
+-- into prev. args are packed
+-- if there's multiple.
+function parser:val(_, ...)
+ local ret := pack(...)
+ if (#ret == 1) return ret[1]
+ return ret
+end
+
+function parser:bind(_, fn, ...)
+ local f = self[fn]
+ return function()
+  f(...)
+ end
+end

todo.md

@@ -0,0 +1,45 @@
+## 1. refine existing engine (knowing what I know now)
+
+- [x] rewrite event queue as a linked list
+- [x] rewrite animator stacks as linked lists
+- [x] rewrite ship/bullet collections as linked lists
+- [ ] update/draw mode switching system (high-efficiency version)
+- [ ] render ship shields (even for large ships)
+- [ ] duplicate file -- about to split away from Tyrian features
+
+## 2. convert from Tyrian clone to MMBN clone
+
+- [ ] remove PWR meter, replace with weapon queue
+- [ ] remove power mechanics from _player_ ship (only!)
+- [ ] all player weapons are now ammo limited except pea shooter
+- [ ] remove weapon drops
+- [ ] implement fallback pea shooter
+- [ ] implement turn timer (screen-height bar)
+- [ ] replace per-frame CLR with rectfill (saves time)
+- [ ] implement extremely crude prototype for weapon select intermezzo
+- [ ] implement "deck"
+- [ ] implement basic weapon cards
+- [ ] implement starter deck
+- [ ] stabilize this with just starter deck and sample level
+
+## 3. add deckbuilder mechanics
+
+- [ ] implement post-encounter "get a card"
+- [ ] implement deck lister
+- [ ] implement more cards, mini-encounters for deck buildup
+- [ ] implement card levels?
+- [ ] implement card removal (shop?)
+
+## 4. make it a real game
+
+- [ ] actually design a branching encounter sequence
+- [ ] map
+- [ ] "minimap"/scanner on weapon picker
+- [ ] high score board (difficulty x time)
+- [ ] difficulty increase system
+- [ ] as much more crap as I can fit in under the token limit, which
+      is probably not much at this point
+
+## 5. this is just futile isn't it
+
+- [ ] give up and move to TIC-80 because the token limits