advent_day_10_pico_8.lua

debug=false
pause=debug
skip_speed=50
start_time=0
t_offset=-5000
x_offset=-5
y_offset=-3
z_offset=-600
pan=0.075
zoom=0.025

function _init()
 t=(start_time or 0)
 mult=8.0
 star_plane=0
 cam={x=0,y=0,z=z_offset}
 
 if (not debug)music(0)
 
 t=step(t)
end

function _update60()
 if btn(5) then
  if btn(2) then
   cam.z-=cam.z*zoom
  elseif btn(3) then
   cam.z+=cam.z*zoom
  end

  if pause then
   if btnp(0) then
    t=step(-1)
   elseif btnp(1) then
    t=step()
   end
  else
   if btnp(0) then 
    t=step(-skip_speed)
   elseif btnp(1) then
    t=step(skip_speed)
   end
  end
 else
  if btn(0) then
   cam.x+=cam.z*pan
  elseif btn(1) then
   cam.x-=cam.z*pan
  elseif btn(2) then 
   cam.y+=cam.z*pan
  elseif btn(3) then
   cam.y-=cam.z*pan
  end
  if not pause then
   t=step()
  end
 end

 if (btnp(4)) then
  pause=not pause
 end

 if (btn(0))btnl="⬅️" else btnl=""
 if (btn(1))btnr="➡️" else btnr=""
 if (btn(2))btnu="⬆️" else btnu=""
 if (btn(3))btnd="⬇️" else btnd=""
 if (btn(4))btnz="🅾️" else btnz=""
 if (btn(5))btnx="❎" else btnx=""
end

function _draw()
 cls()

 for s in all(stars) do
  draw_point(s)
 end

 color(11)
 rect(0, 0, 127, 127)

 print('t: '..t+t_offset,4,4)
 print('x: '..flr(cam.x),4, 12)
 print('y: '..-flr(cam.y),4,20)
 print('z: '..(flr(cam.z)),4,28)
 print(btnz,48,116)
 print(btnx,48,116)
 print(btnl,56,116)
 print(btnr,70.5,116)
 print(btnu,63.5,112)
 print(btnd,63.5,120)
end

function step(m) 
 for s in all(stars) do 
  s.x+=s.vx*(m or 1)
  s.y+=s.vy*(m or 1)
 end
 
 return increment(t,m)
end

function increment(n, amount)
 n+=(amount or 1)
 
 return n
end
 
function draw_point(p)
 local x,y=project(p)
 if cam.z>=-1 then
  spr(star_sprite_color(),x,y)
 else
  pset(x,y,star_color())
 end
end

function project(p)
 local x=(p.x-cam.x+x_offset)*mult/(star_plane-cam.z)+127/2 
 local y=(p.y-cam.y+y_offset)*mult/(star_plane-cam.z)+127/2
    
 return x, y
end

function star_color()
 return shuffle_colors({7,7,7,7,7,0,1})
end

function star_sprite_color()
 return shuffle_colors({2,2,2,2,3,3,4})
end

function shuffle_colors(colors)
 local i=ceil(rnd(#colors))
 return colors[i]
end

stars={
 {x=9,y=-9999,vx= 0,vy= 2},{x=5007,y=0,vx=-1,vy= 0},{x=5003,y=-5002,vx=-1,vy= 1},{x=10006,y=5010,vx=-2,vy=-1},{x=-9998,y=-10004,vx= 2,vy= 2},{x=-10006,y=10010,vx= 2,vy=-2},{x=-4999,y=5008,vx= 1,vy=-1},{x=-4999,y=7,vx= 1,vy= 0},{x=-5003,y=10011,vx= 1,vy=-2},{x=5007,y=5006,vx=-1,vy=-1},{x=-5002,y=3,vx= 1,vy= 0},{x=-10004,y=3,vx= 2,vy= 0},{x=5010,y=-5003,vx=-1,vy= 1},{x=-4995,y=10011,vx= 1,vy=-2},{x=4,y=5007,vx= 0,vy=-1},{x=8,y=-5002,vx= 0,vy= 1},{x=10015,y=0,vx=-2,vy= 0},{x=-4999,y=6,vx= 1,vy= 0},{x=8,y=5009,vx= 0,vy=-1},{x=5003,y=-4997,vx=-1,vy= 1},{x=0,y=5005,vx= 0,vy=-1},{x=-10002,y=2,vx= 2,vy= 0},{x=-4995,y=-10002,vx= 1,vy= 2},{x=-9999,y=-4996,vx= 2,vy= 1},{x=-10002,y=10007,vx= 2,vy=-2},{x=5003,y=5006,vx=-1,vy=-1},{x=-4995,y=0,vx= 1,vy= 0},{x=-10006,y=0,vx= 2,vy= 0},{x=-4995,y=10009,vx= 1,vy=-2},{x=10014,y=7,vx=-2,vy= 0},{x=-10003,y=5006,vx= 2,vy=-1} 
}