Computer Science Canada :: View topic - Breakout-styled game problems

var gx, gy : int %ball
var bchangex, bchangey : int := 5 %ball change
var bspeed : int
var bcolor : int
var bsize : int
var x1, x2, y1, y2 : int %paddle
var boxx, boxy, boxx2, boxy2: int %bricks
var chars : array char of boolean
var speed: int

speed := 5
x1 := 100
x2 := 10
gx := 10
gy := 10
y1 := 10
y2 := 20

setscreen ("graphics:max;max,nobuttonbar,title:D:")

View.Set ("offscreenonly")

locate (23, 30)
put "Before starting the program, make sure your dimensions are at 1024x728."
delay (2000)

colorback (31)
cls

loop

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%paddle

Input.KeyDown (chars)
if chars (KEY_RIGHT_ARROW) then
x1 := x1 + 10
x2 := x2 + 10
if x1 > 1000 then
x1 := 999
end if
if x2 > 900 then
x2 := 899
end if
View.Update

cls
end if
if chars (KEY_LEFT_ARROW) then
x1 := x1 - 10
x2 := x2 - 10
if x1 < 100 then
x1 := 90
end if
if x2 < 1 then
x2 := 1
end if
View.Update

cls
end if

drawfillbox (x1, y1, x2, y2, 78)

bcolor := red
bsize := 7

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%ball and ball collision

Draw.Oval (gx, gy, bsize, bsize, bcolor)
View.Update

if gx <= 0 then
bchangex := 1
elsif gy <= 1 then
bchangey := 1
end if

if gx >= maxx then
bchangex := -1
elsif gy >= maxy then
bchangey := -1
end if

gx += bchangex
gy += bchangey

cls

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%paddle collision

if gx + bsize > x1 - x2 and gx - bsize < x1 + x2 and gy + bsize > y1 - y2 and gy - bsize < y1 +
y2 then

bchangex := bchangex * +1
bchangey := bchangey * -1

end if

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%bricks and brick collision

boxx := 100
boxy := 150
boxx2 := 300
boxy2 := 200

Draw.Box (boxx, boxy, boxx2, boxy2, black)

if bchangex > 0 then
if whatdotcolor (gx + bchangex + bsize, gy) = black then
Draw.Box (boxx, boxy, boxx2, boxy2, white)
bchangex := -bchangex
end if
else
if whatdotcolor (gx + bchangex - bsize, gy) = black then
Draw.Box (boxx, boxy, boxx2, boxy2, white)
bchangex := +bchangex
end if
end if

if bchangey > 0 then
if whatdotcolor (gx, gy + bchangey + bsize) = black then
Draw.Box (boxx, boxy, boxx2, boxy2, white)
bchangey := -bchangey
end if
else
if whatdotcolor (gx, gy + bchangey - bsize) = black then
Draw.Box (boxx, boxy, boxx2, boxy2, white)
bchangey := +bchangey
end if
end if

Author:	Delos [ Wed Jun 01, 2005 1:01 pm ]
Post subject:
Let me see if I understand you: - You draw a black box that acts as your 'bumper' - Keyboard input (or something else) moves this bumper - To clear the previously drawn bumper, you draw a white box over it If this is the case, as I think it is, there's an easier way: - do this in a loop, your 'main' loop that controls everything - draw your box - do other necassary stuff like checking for collision, input etc - Update the Screen - pause (delay) for a bit - clear the screen This requries you to use setscreen("offscreenonly") and View.Update. It's a lot easier than dynamically locating and clearing only portions of the screen. However, that being said, if you really want to clear only portions, you can use View.UpdateArea() but please be aware that if you have other objects on the screen (the bricks to be brocken for example), you'll have to set up sepearte Updates for them as well!

Author:	ziddy [ Wed Jun 01, 2005 1:38 pm ]
Post subject:
Sorry, I'll update my post with the whole program's code in it, instead of just the part I was having trouble with. And I'm sorry for not making myself clear enough :S Okay, here's the deal. The black box is actually the brick in which the ball has to hit to score and move onto the next level. The bumper is a blue box(please check updated code). And yeah I have done most of the things you have said, the only other thing that confuses me is where exactly should I put my View.Updates? I got help with the ones in my code from a friend and neglected to ask him where I should put my next View.Updates

Author:	Neo [ Wed Jun 01, 2005 2:12 pm ]
Post subject:
For this type of program you really only need 1 view.update, 1 delay and one cls. These usually go at the end of the program because you only need to update the screen after you have drawn everything, clear it, then redraw it again, clear it again and so on...