trig zap gun; fixes

use the trig gun for the zap gun

vacuum_gambit.p8

@@ -29,23 +29,33 @@ end
 -- if tt.init is defined, generated
 -- new calls tt.init(ret) after
 -- ret is definitely not nil,
--- before calling setmetatable.
+-- after 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.
+-- it is invoked before
+-- setting tt's metatable, so
+-- each new will see its
+-- inheritance chain.
 function mknew(tt)
- local mt,oldnew,more = {__index=tt},tt.new,rawget(tt, "init")
+ local mt,oldinit,more = {__index=tt},tt.superinit,rawget(tt, "init")
  tt.new=function(ret)
   if(not ret) ret = {}
-  if(more) more(ret)
-  if(oldnew) oldnew(ret)
+  ret.new = false
   setmetatable(ret, mt)
+  if(oldinit) oldinit(ret)
+  if (more) more(ret)
   return ret
  end
+
+ if oldinit and more then
+  tt.superinit = function(ret)
+   oldinit(ret)
+   more(ret)
+  end
+ elseif more then
+  tt.superinit = more
+ end
  return tt
 end
 
@@ -520,8 +530,6 @@ ship_m = mknew{
  shieldpenalty = 0x0.012c, --5s
  shield_refresh_ready = 0,
  
- slip = true,  -- most enemies slide
- 
  xmomentum = 0,
  ymomentum = 0,
 
@@ -605,21 +613,13 @@ function ship_m:move()
  self:maybe_shoot(self.main_gun)
  if (shoot_spec1 and self.special_guns) self:maybe_shoot(self.special_guns[1])
  if (shoot_spec2 and self.special_guns) self:maybe_shoot(self.special_guns[2])
- if (dx ~= 0 or dy ~= 0) spark(self.sparks, self.x + 4*self.size, self.y + 4*self.size, dx*2.5, dy*2.5, self.sparkodds)
+ spark(self.sparks, self.x + 4*self.size, self.y + 4*self.size, dx*2.5, dy*2.5, self.sparkodds)
  self.xmomentum = self:calc_velocity(self.xmomentum, dx)
  self.ymomentum = self:calc_velocity(self.ymomentum, dy)
 
  self.x += self.xmomentum
  self.y += self.ymomentum
 
- -- "scrolling" behavior
- if self.slip then
-  self.y += scrollrate
-  if self.y >= 128 then
-   self:die()
-   return true
-  end
- end
  return false
 end
 
@@ -719,6 +719,10 @@ bullet_base = mknew{ }
 
 gun_base = mknew{ 
  shoot_ready = -32768,
+ new_clip = -32768,
+ clip_size = false,
+ clip_remain = 0,
+ clip_interval = 0x0.80,
  icon = 20,
  ammobonus = 1,
 
@@ -849,15 +853,75 @@ end
 
 function gun_base:shoot(x, y)
  if (gframe < self.shoot_ready) return false
+ local csz,crm = self.clip_size, self.clip_remain
+ if csz then
+  if crm < csz and gframe >= self.new_clip then
+   self.clip_remain = csz
+   self.new_clip = gframe + self.clip_interval
+  elseif crm == 0 then
+   return false
+  end
+ end
  if self.ammo then
   if (self.ammo <= 0) return false
   self.ammo -= 1
  end
+ if csz then
+  self.clip_remain -= 1
+ end
  self.shoot_ready = gframe + self.cooldown
  self:actually_shoot(x, y)
  return true
 end
 
+trig_gun = mknew(gun_base.new{
+ veloc = 1,
+ aim = 0.75, -- down; 0.25 is up
+ shot_idx = 0,
+ -- shots: list<list<[3]num>>
+ --  describing a cycling
+ --  firing pattern. shot_idx
+ --  tracks offset into pattern.
+ -- each nested list: a burst
+ --  of shots to fire; takes
+ --  1 ammo; sequential
+ -- each shot: angle (turns,
+ --  relative to `aim`),
+ --  velocity, firing x-offset;
+ --  if velocity is nil, use
+ --  self.veloc instead;
+ --  if x-offset is nil, use 0
+ init = function(self)
+  if (not self.shots) self.shots = {{{0}}}
+ end
+})
+
+function trig_gun:actually_shoot(x, y)
+ local shots,veloc,aim,munition = self.shots,self.veloc,self.aim,self.munition
+ local idx = self.shot_idx % #shots + 1
+ self.shot_idx = idx
+ shots = shots[idx]
+ for s in all(shots) do
+  local a,v,xo = unpack(s)
+  v = v or veloc
+  a += aim
+  -- todo: switch munition
+  --  depending on angle
+  --  (allows for non-round
+  --   sprites and hitboxes on
+  --   shots from guns with
+  --   widely varying angles)
+  local m = munition.new{}
+  -- todo: automatically make
+  -- high velocity shots do
+  -- multiple collision checks
+  m.dy = sin(a) * veloc
+  m.dx = cos(a) * veloc
+  m:spawn_at(x+(xo or 0), y)
+ end
+end
+
+
 -->8
 -- bullets and guns
 
@@ -876,8 +940,6 @@ zap_e = mknew(bullet_base.new{
  y_off = 8,
  
  damage = 1,
- dx = 0,  -- px/frame
- dy = 4,
 
  hitship = const_fxn(true),
 
@@ -886,19 +948,21 @@ zap_e = mknew(bullet_base.new{
 
 zap_p = mknew(zap_e.new{
  sprite = 8,
- dy = -8,
  y_off = 0,
  category = player_blt_cat,
 })
 
-zap_gun_e = mknew(gun_base.new{
+zap_gun_e = mknew(trig_gun.new{
  cooldown = 0x0.0020, -- frames between shots
+ veloc = 4,
  munition = zap_e,
 })
 
 zap_gun_p = mknew(zap_gun_e.new{
  icon = 19,
  munition = zap_p,
+ veloc = 8,
+ aim = 0.25,
  hdr = "mAIN gUN",
 })
 
@@ -1074,7 +1138,6 @@ vulcan_p = mknew(vulcan_e.new{
 
 vulcan_gun_e = mknew(gun_base.new{
  icon = 37,
- enemy = false,
  cooldown = 0x0.0003, -- frames between shots
  ammo = nil,
  maxammo = nil,
@@ -1092,6 +1155,14 @@ vulcan_gun_e = mknew(gun_base.new{
  end
 })
 
+machine_gun_e = mknew(vulcan_gun_e.new{
+ icon = 38,
+ clip_size = 12,
+ clip_interval = 0x0.005a,
+ dxs = {0, 0},
+ xoffs = {1, -1},
+})
+
 vulcan_gun_p = mknew(vulcan_gun_e.new{
  munition=vulcan_p,
  maxammo = 100,
@@ -1156,7 +1227,6 @@ player = mknew(ship_m.new{
  thrust = 0.1875, -- momentum added from button
  ymin = 0, ymax = 120, -- stay on screen
  drag = 0.0625, -- momentum lost per frame
- slip = false, -- does not slide down screen
  act = function(self)  -- fetch buttons
   local b,th = btn(),self.thrust
   local blr = b&0x3
@@ -1312,7 +1382,6 @@ chasey = mknew(ship_m.new{
  maxspd = 2,
  thrust = 0.2,
  drag = 0.075,
- slip = true,
 
  init = function(ship)
   ship.main_gun=ship.main_gun or zap_gun_e.new{}
@@ -1340,7 +1409,6 @@ xl_chasey=mknew(chasey.new{
  hp = 19.5,
  shield = 5,
  boss = true,
- slip = false,
  act = function(self)
   local dx,dy,shoot_spec,shoot_main = chasey.act(self)
   if (self.y < 4) dy=self.thrust
@@ -1351,9 +1419,6 @@ xl_chasey=mknew(chasey.new{
   sspr(40, 0, 8, 8, self.x, self.y, 16, 16)
   pal()
  end,
- init = function(ship)
-  ship.main_gun=ship.main_gun or zap_gun_e.new{}
- end,
 })
 
 -- flotilla ships
@@ -1365,16 +1430,20 @@ ship_f = mknew(ship_m.new{
  -- no sparks
  hp = 0.5,
  xp = 0x0.0001,
+ fire_off_x = 4,
+ fire_off_y = 4,
 
  maxspd = 3,
  thrust = 0.1,
  drag = 0.05,
- slip = false,
  act = function(self)
   local wx,wy=self.want_x,self.want_y
   self.xmin,self.xmax,self.ymin,self.ymax = wx,wx,wy,wy
   return 0,0,false,false
  end,
+ init = function(self)
+  if (self.gun_proto) self.main_gun = self.gun_proto.new()
+ end
 })
 
 ship_mook = mknew(ship_f.new{
@@ -1388,12 +1457,14 @@ ship_defender = mknew(ship_f.new{
 ship_turret = mknew(ship_f.new{
  sprite=106,
  xp = 0x0.0002,
+ gun_proto = machine_gun_e,
 })
 ship_skirmisher = mknew(ship_f.new{
  sprite=107,
  xp = 0x0.0004,
- spark = smokespark,
- sparkodds = 4,
+ sparks = smokespark,
+ sparkodds = 3,
+ fire_off_y = 7,
 })
 
 function rnd_spawn_loc()
@@ -1695,15 +1766,15 @@ function spark_particle:draw()
 end
 
 function spark(sprs, x, y, dx, dy, odds, fg)
- if (sprs==nil or flr(rnd(odds)) ~= 0) return
+ if (sprs==nil or flr(rnd(odds) or (abs(dx) < 0.5 and abs(dy))) ~= 0) return
  local target = fg and intangibles_fg or intangibles_bg
  target:push_back(spark_particle.new{
   x = x + rnd(4) - 2,
   y = y + rnd(4) - 2,
   sprs = sprs,
   sidx = 1,
-  dx = dx + rnd(2) - 1,
-  dy = dy + rnd(2) - 1,
+  dx = dx * rnd(2),
+  dy = dy * rnd(2),
  })
 end
 -->8