weird effect

DanShadow · **Posted:** Sat Dec 13, 2003 8:49 pm

I got bored, start messing with lines, created some stairway thing.. Smile

code:

Draw.FillBox (0, 0, maxx, maxy, 255)
locate (13, 25)
color (12)
colorback (black)
put "Come..."
locate (14, 25)
put "take the gateway.."
locate (15, 25)
put "follow the steps..."
locate (16, 25)
put "enter the stars...."
delay (8000)
var x, y : int := 200
var num := 50
Draw.FillBox (0, 0, maxx, maxy, 255)
for i : 1 .. 50
var xer, yer : int := 0
randint (xer, 1, 640)
randint (yer, 1, 400)
Draw.Dot (xer, yer, 14)
end for
num := 50
loop
delay (5)
Draw.Line (x + num, y + 50, x, y, 2)
num := num + 1
y := y - 1
exit when y < 0 - 50
end loop
var xer : int := 0
loop
randint (num, 1, 3)
Draw.FillOval (x + 25, y + 325, 30, 70, num)
xer := xer + 1
if xer = 10000 then
locate (5, 30)
put "k....close the program now..."
end if
end loop

or maybe this odd thing

code:

var x, y, num : int := 200
num := 0
var modi : int := 1
Draw.FillBox (0, 0, maxx, maxy, 255)
loop
Draw.Oval (x + num, y - 50, x, y, 14)
delay (5)
Draw.Oval (x + num, y - 50, x, y, 12)
delay (5)
num := num + 1
Draw.Oval (x + num, y - 50, x, y, 2)
y := y + modi
if y < 0 then
modi := 1
elsif y > maxy then
modi := -1
end if
end loop

DanShadow · **Posted:** Sat Dec 13, 2003 8:55 pm

hmm...i think i found a glitch in turing

code:

var x, y, num : int := 200
num := 0
loop
num := num + 1
Draw.Line (x + num, y - 50, x, y, 255)
y := y - 1
end loop

Leave that running for a mniute, and watch it. See how in the code, the "y" axis is ONLY supposed to decrease? Well then how does it end up higher than the original "y" valu e of 200? *spooky* Shocked

Dan · **Posted:** Tue Dec 16, 2003 12:47 pm

same thing will happen in c/c++ but it will take alot longer.

that is what most progaming languges do when you hit max number (or min), they go back to some set number. it is praty so the hole comp dose not crash when you get a value over the x big.

DanShadow · **Posted:** Wed Dec 17, 2003 12:00 pm

Oh I see...except seemingly when in C++, when you reach a "too" large integer, it crashes the program, heh.

Tony · **Posted:** Wed Dec 17, 2003 1:17 pm

This all has to do with the way signed numbers work.

Anyone knows how to represent negative numbers in binary? Laughing

Binary numbers have a leading bit. 0 for possitive, 1 for negative. When you overflow the number - say you have an 8 bit integer. It is actually 9 bits long. So when you have 256+1, in binary its

011111111
+1
100000000

now since the integer is only 8 bits long, this number represents negative 0. As you add more, you keep on going backwards.

100000001
is -1 and so on.

The reason for C++ to take "longer" is because integers are "longer" - meaning more bits to fill before overflow.

kalin · **Posted:** Tue Jan 20, 2004 3:37 pm

Both of those things are really really really really *cough cough* wierd

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