OpenEuphoria

Re: Chock full o' bugs

• Posted by Brian Broker <bkb at CNW.COM> Sep 22, 2000
• 479 views

On Thu, 21 Sep 2000 21:02:14 -0700, Thomas wrote:

>I've written a program I'd like someone too look over. At the moment, it's
>a hairy mess.The objective was to have a little tank that fired a beam
>that came from the tip of the turret. The user could move the turret too.
>Could you tell me what went wrong or if it's less work re-write the
>program so I can see what a 'clean' version looks like? Thanks

OK Thomas, this is what I've come up with.  I started with your original
program so it's a bit hacked together and mostly redone.  There is much
room for improvement and features IMO.  I'll leave that to you...

Your first assignment is figuring out how to control the bullet because I
think there are times where you can't hit the target (you'll be either too
high or too low).

I apologize for lack of comments but I try to name my variables
informatively and do things such that I hope it's self-explanatory.

So without further ado...

-- Sha-boom.ex
--  started by Thomas
--   tinkered with by Brian
include graphics.e
include image.e
include get.e

constant
  X = 1,
  Y = 2,
  UPPER = 1,
  LOWER = 2,
  TRUE = 1,
  FALSE = 0,
  MAX = {320,200}  -- screen size for mode 19

integer gmode, inkey
  gmode = graphics_mode(19)

sequence turret_p1, turret_p2, turret_limit, target

--------------------

procedure wait( atom pinterval )
  atom endtime

  endtime= time()+pinterval
  while endtime > time() do
  end while
end procedure

  --------------------

procedure draw_target()
  -- initialize target
  target = {0,0}
  -- set target
  target[X] = MAX[X] - 20
  target[Y] = 10 + rand( MAX[Y] - 20 )
  -- draw target
  ellipse( RED, 1, target-{6,10}, target+{6,10} )
  ellipse( WHITE, 1, target-{3,5}, target+{3,5} )
end procedure

  --------------------

function target_hit( atom y )
  if y > target[Y]-10 and y < target[Y]+10 then
    return TRUE
  else
    return FALSE
  end if
end function

  --------------------

procedure draw_tank( integer x, integer y )
  -- draw_tank
  ellipse( GREEN, 1, {x+2,y}, {x+12,y+10} )
  polygon( GREEN, 1, {{x,y+5},{x+20,y+5},{x+20,y+10},
                      {x+15,y+15},{x+5,y+15},{x,y+10}} )
  polygon( BROWN, 0, {{x,y+10},{x+20,y+10},{x+15,y+15},{x+5,y+15}} )

  -- set turret_limit = { upper limit, lower limit }
  turret_limit = {y-8,y+3}
  -- draw turret
  turret_p1 = {x+11, y+1}
  turret_p2 = {x+20, y+1}
  draw_line(2,{turret_p1,turret_p2})
end procedure

  --------------------

function get_slope()
  return (turret_p2[Y] - turret_p1[Y]) / (turret_p2[X] - turret_p1[X])
end function

  --------------------

procedure explode()
  integer pix

  ellipse( BLACK, 1, target-{6,10}, target+{6,10} )

  for y = -15 to 15 do
    for x = -15 to 15 do
      pix = rand(10)-8
      if pix > 0 then
        if pix = 1 then
          pixel( RED, target + {x,y} )
        else
          pixel( WHITE, target + {x,y} )
        end if
      end if
    end for
  end for
end procedure

  --------------------

procedure fire()
  integer lcolr
  sequence laser_p1, laser_p2, last_p1, last_p2

  -- initialize last points to off-screen
  last_p1 = {-1,-1}
  last_p2 = {-1,-1}

  -- initialize start of laser to end of turret
  laser_p1 = turret_p2

  while 1 do
    inkey = get_key()
    if inkey = 'q' then
      -- quit --
      gmode = graphics_mode(-1)
      abort(0)
    end if

    wait( 0.005 )

    lcolr = rand(15)
    laser_p2 = laser_p1 + {5, 5*get_slope()}

    draw_line( lcolr, {laser_p1,laser_p2} )
    draw_line( BLACK, {last_p1, last_p2} )

    last_p1 = laser_p1
    last_p2 = laser_p2

    laser_p1 = laser_p2

    if laser_p2[X] > target[X] then
      if target_hit( laser_p2[Y] ) then
        puts(1,"\n\n                SHA-BOOM!" )
        explode()
      else
        puts(1,"\n\n                MISSED!" )
      end if
      return
    end if
  end while
end procedure

  --------------------

-- MAIN PROGRAM LOOP --
while 1 do
  clear_screen()
  draw_target()
  draw_tank( 10, 135 + rand( MAX[Y]-155 ) )
  while 1 do
    inkey = wait_key()
    if inkey = 'q' then
      -- quit --
      gmode = graphics_mode(-1)
      abort(0)
    elsif inkey = 'u' then
      -- move turret up --
      if turret_p2[Y] > turret_limit[UPPER] then
        draw_line(0,{turret_p1,turret_p2})
        turret_p2[Y] -= 1
        draw_line( GREEN,{turret_p1,turret_p2})
      end if
    elsif inkey = 'd' then
      -- move turret down --
      if turret_p2[Y] < turret_limit[LOWER] then
        draw_line(0,{turret_p1,turret_p2})
        turret_p2[Y] += 1
        draw_line( GREEN,{turret_p1,turret_p2})
      end if
    elsif inkey = 'f' then
      -- fire! --
      fire()
      -- play again? --
      puts( 1, "\n           Play Again? (y/n)" )
      if wait_key() = 'y' then
        exit      -- exit inner while loop
      else
        abort(0)  -- exit program
      end if
    end if
  end while
end while

-- have fun!!!
-- Brian