// Head with Annoying Objects

// move the mouse around to attract the outlined
// volume

load dbngraphics.dbn

set total_points 11

set old_offset 500

set current_pressure 0
set total_volume   0
set current_volume 0

set noise 15

set gravity (10000)
set gravity_x 50
set gravity_y 0

set pertime 10

set bar_len (180/total_points)
set bar_len_sqr (bar_len*bar_len)

set tension_div 5

set bb 198621
set mm 98621
set seed <time 4>
number random range
{
   set bl (seed*bb+1)
   set seed (bl % mm)
   value (seed % range)
}

repeat a 0 (total_points/2-1)
{
   set <array (a*2+1)> ((<random noise>-noise/2+10+a*80/(total_points-1)))
   set <array (a*2+2)> ((<random noise>+a*180/(total_points-1)))
}
repeat a (total_points/2) (total_points-1)
{
   set <array (a*2+1)> ((<random noise>-noise/2+10+a*80/(total_points-1)))
   set <array (a*2+2)> ((<random noise>+180-a*180/(total_points-1)))
}
set a 0
set <array (a*2+1)> (10)
set <array (a*2+2)> (0)
set a (total_points-1)
set <array (a*2+1)> (90)
set <array (a*2+2)> (0)
command drawblob
{
   set draw_i 0
   set x1 <array ((draw_i*2)+1)>
   set y1 <array ((draw_i*2)+2)>
   set ox1 <array (old_offset+(draw_i*2)+1)>
   set oy1 <array (old_offset+(draw_i*2)+2)>
   pen 100
   repeat draw_i 1 (total_points-1)
   {
      set x2 <array ((draw_i*2)+1)>
      set y2 <array ((draw_i*2)+2)>
      set ox2 <array (old_offset+(draw_i*2)+1)>
      set oy2 <array (old_offset+(draw_i*2)+2)>
      pen 15
      line (ox1) (oy1) (ox2) (oy2)
      pen 100
      line (x1) (y1) (x2) (y2)
      set x1 x2
      set y1 y2
      set ox1 ox2
      set oy1 oy2
   }
}

number abs abs_value
{
   smaller? abs_value 0
   {
      value (-abs_value)
   }
   notsmaller? abs_value 0
   {
      value abs_value
   }
}

number sqr sqr_value
{
   value (sqr_value*sqr_value)
}

command moveblob
{
   set a 0
   set lx <array (a*2+1)>
   set ly <array (a*2+2)>
   set x <array ((a+1)*2+1)>
   set y <array ((a+1)*2+2)>
   repeat a 1 (total_points-2)
   {
      set nx <array ((a+1)*2+1)>
      set ny <array ((a+1)*2+2)>

      set tensionl (<abs (x-lx)>+<abs (y-ly)>-bar_len)
      set tensionn (<abs (nx-x)>+<abs (ny-y)>-bar_len)
      set vxl ((lx-x)*tensionl)
      set vyl ((ly-y)*tensionl)
      set vxn ((nx-x)*tensionn)
      set vyn ((ny-y)*tensionn)
      set vxg ((gravity_x-x)*gravity/(<sqr (gravity_x-x)>+<sqr (gravity_y-y)>))
      set vyg ((gravity_y-y)*gravity/(<sqr (gravity_x-x)>+<sqr (gravity_y-y)>))
      set cy (y+(current_pressure+vyg+(vyl+vyn)/tension_div)/total_points/pertime)
      set cx (x+(vxg+(vxl+vxn)/tension_div)/total_points/pertime)
      smaller? cy 0
      {
         set cy 0
      }

      set <array (a*2+1)> cx
      set <array (a*2+2)> cy

      set lx x
      set ly y
      set x nx
      set y ny
   }
}

number calc_volume
{
   set add_value 0
   repeat a 1 (total_points-1)
   {
      set x <array (a*2+1)>
      set y <array (a*2+2)>
      set add_value (add_value + (y*(<sqr (x-50)>+<sqr y>)))
   }
   value add_value
}

set total_volume (<calc_volume>)

command save_old_data
{
   repeat a 0 total_points
   {
      set <array (old_offset+(a*2+1))> <array (a*2+1)>
      set <array (old_offset+(a*2+2))> <array (a*2+2)>
   }
}

number sign sign_value
{
   smaller? 0 sign_value
   {
      value (-1)
   }
   notsmaller? 0 sign_value
   {
      value 1
   }
}

set total_volume (<calc_volume>)

set main_loop 0

forever
{
   set main_loop (main_loop + 1)
   set current_volume <calc_volume>
   set current_pressure ((total_volume-current_volume)/1000)

   pen 25
   line (gravity_x-5) (gravity_y) (gravity_x+5) (gravity_y)
   line (gravity_x) (gravity_y-5) (gravity_x) (gravity_y+5)
   line (gravity_x-5) (gravity_y) (gravity_x) (gravity_y-5)
   line (gravity_x) (gravity_y-5) (gravity_x+5) (gravity_y)
   line (gravity_x+5) (gravity_y) (gravity_x) (gravity_y+5)
   line (gravity_x) (gravity_y+5) (gravity_x-5) (gravity_y)
   set gravity_x <mouse 1>
   set gravity_y <mouse 2>
   save_old_data
   moveblob
   drawblob
   pen 100
   line (gravity_x-5) (gravity_y) (gravity_x+5) (gravity_y)
   line (gravity_x) (gravity_y-5) (gravity_x) (gravity_y+5)
   line (gravity_x-5) (gravity_y) (gravity_x) (gravity_y-5)
   line (gravity_x) (gravity_y-5) (gravity_x+5) (gravity_y)
   line (gravity_x+5) (gravity_y) (gravity_x) (gravity_y+5)
   line (gravity_x) (gravity_y+5) (gravity_x-5) (gravity_y)
}