--sprite draw on angle
function spra(angle,n,x,y,w,h,f_x,f_y)
  if w==nil or h==nil then
   w,h=8,8
  else
   w=w*8
   h=h*8
  end
  local diag,w,h=flr(sqrt(w*w+h*h))/2,w/2,h/2
  f_x,f_y=f_x and -1 or 1,f_y and -1 or 1
  local cosa,sina,nx,ny=cos(angle),sin(angle),n%16*8,flr(n/16)*8
  for i=-diag,diag do
   for j=-diag,diag do
    local ox,oy=(cosa*i + sina*j),(cosa*j - sina*i)
    if ox==mid(-w,ox,w) and oy==mid(-h,oy,h) then
     local col=sget(ox+w+nx,oy+h+ny)
     if col!=14 then
      --if(f_x*i+w>5) then col = darken[col]; end --shading and light hack
      pset(x+f_x*i+w,y+f_y*j+h,col)
     end
    end
   end
  end
 end