Computer Science Canada Programming C, C++, Java, PHP, Ruby, Turing, VB   Username:   Password: Wiki   Blog   Search   Turing   Chat Room  Members
Many Balls bouncing
Author Message
Cervantes

Posted: Mon Feb 16, 2004 7:56 pm   Post subject: (No subject)

It's kinda like thinking in another dimension.. I guess
Everyone how has spoken in this thread so far could do that with one ball. Two balls? Yes, just have 2 x vars and 2 y vars etc. 100 balls? It's harder, but it really isn't that hard.

When you've got the for loops going 100 balls is basically simplified into 1 ball. Wherever you would say something like
 code: ballx += balldx bally += balldy

you actually have
 code: for i : 1 .. howmanyballs ballx (i) += balldx (i) bally (i) += balldy (i) end for

xmen

Posted: Fri Mar 26, 2004 7:16 pm   Post subject: "array subscript is out of range" ERROR!!!!!!

Cervantes wrote:
....

its not nearly done but w/e just for fun

at first when i was running this program it went fine. but after awhile, an error suddenly pops up saying "array subscript is out of range" for:
Cervantes wrote:
....
if x (i) > maxx - ballradius then

do any of u kno why??
i also notice when i change the # of balls n the radius of balls this error appears earlier.....plzz show me how to fix this
xmen

Posted: Fri Mar 26, 2004 7:57 pm   Post subject: ALSO

how come sometimes the balls move very slowly while sometimes very fast??

how can i fix the problem where the ball get stuck on one of the sides (kinda start shaking)
Hackster

Posted: Sat Mar 27, 2004 12:44 am   Post subject: (No subject)

Here's a bouncy ball program that is in a totally random pattern

hope you like!
Cervantes

Posted: Sat Mar 27, 2004 10:13 am   Post subject: (No subject)

[quote=xmen][quote=Cervantes]....
if x (i) > maxx - ballradius then[/quote]
do any of u kno why??[/quote]

That would be because that line of code is not actually part of my program no idea how you got that, but its:
 code: if x (i) > maxx - 20 - ballradius then

that code simply tells if the x position of ball (i) has hit the wall or not.

xmen, how did you last long enough to notice that things speed up or slow down!! you must have made some alterations on my code, because I can't get past 7 of those guys I guess it does depend on the speed of your computer though. I'm on 1.6ghz 512 mb of ram. What do you have? If your on a relatively slow computer it probably explains why the speed of the balls change: because as more balls are added the program has to go through the for loops more times, taking up more time.
xmen

Posted: Sat Mar 27, 2004 7:03 pm   Post subject: (No subject)

my computer is 1.8 P4 / 256 ram.....well all i did was decrease the # of max balls (in the beginning of program) to like 4, n take out the red ball, everytime i run the program its different

sometimes the first blue ball goes very slow, then the second ball goes very fast, n if any of the balls hit the slow one, the slow one turns fast while the fast one turn slow.....etc

also if i make the size of the ball bigger, once they collide there are some bugs there too, n sometimes these balls just slide along the sides for some reason

i kno these are pretty simple n stupid questions but i reli need answers for them......cuz later on im gonna change the balls into happy faces n make this as screensaver (as one of my assignment).........thnx
Cervantes

Posted: Sat Mar 27, 2004 7:42 pm   Post subject: (No subject)

You can use my code as a reference, but don't cut and paste and change a few things to make it look like your own code. Just a warning, I don't know if you were planning on doing that or not.
Anyways, take a look at this part of the program:
 code: for i : 1 .. totalballs     x (i) := Rand.Int (20 + ballradius, maxx - 20 - ballradius)     y (i) := Rand.Int (20 + ballradius, maxy - 20 - ballradius)     dx (i) := Rand.Int (-3, 3)     dy (i) := Rand.Int (-3, 3) end for

This explains why certain balls begin at a faster pace then others. dx represents the balls speed along the x axis, and dy represents the balls speed along the y axis.
later, this code appears:
 code: x (i) += dx (i) y (i) += dy (i)

that code is inside the main loop, so every time that code executes, the value of dx is added to x, and dy to y.
Because dx and dy are created using Rand.Int, the balls begin with different speeds.
As for when they collide, the balls transfer energy between each other, speeding one up and slowing the other down.
you should note though that the collision data in this is rather messed up though.
xmen

Posted: Sat Mar 27, 2004 11:10 pm   Post subject: (No subject)

Cervantes hav u tried letting ur program run for awhile (with like 6 balls, delete the red one) n get this error saying "array subscript is out of range" ??

how do i fix that??

Cervantes

Posted: Sun Mar 28, 2004 10:30 am   Post subject: (No subject)

you fix that by increasing the totalballs variable at the top of the program.
xmen

Posted: Sun Mar 28, 2004 11:58 am   Post subject: (No subject)

but wut if i only want 6 balls appearin in total??
well wut ive tried was set the totalballs to a large nuber (like 50, so that the program can continue longer) n then i put exit when i=7 to the part of actually drawin the balls

this worked completely fine (only 6 balls appeared) BUT if i was to leave the program on longer, it'll laaaaaaaaaaaaaaaggggggg like crazy, not cuz of my system, it was bcuz of the colliding part of this program was still calculating stuffs using the totalballs ive set (50)

so is there any way i can hav this program run forever with only like 6 balls but no lag afterwards??
Cervantes

Posted: Sun Mar 28, 2004 12:32 pm   Post subject: (No subject)

uh-huh. all you do is set totalballs to 6 and comment out the bit about the timer.
xmen

Posted: Sun Mar 28, 2004 2:01 pm   Post subject: (No subject)

ok thnx

sry but one last question.......u see rite now im making screensaverS for an assignment. it starts with a "menu" (just simply with GUI buttons) for viewing the 5 screensavers, so the first button is screen 1 n etc

but the problem is, if i was to copynpaste all 5 screensavers' codes and complie them into one program for this assignment, im thinking that i'll lag quite alot (especially with school computers). so i justwanna ask u if theres a command (for GUI button procedure) to read n run another turing file/program once i click GUI button 1,2,3...... so i'll hav 6 programs
with 5 screensavers and one "menu" page
Cervantes

Posted: Sun Mar 28, 2004 6:57 pm   Post subject: (No subject)

F10 on include
Homer_simpson

Posted: Mon Mar 29, 2004 2:57 am   Post subject: (No subject)

we64 wrote:
I changed it based on Cervantes' code... Now it really bouncing around screen...
 code: var howmany : int put "How many balls? : " .. get howmany var x, y, dx, dy : array 1 .. howmany of int for i : 1 .. howmany     dx (i) := Rand.Int (-4, 4)     dy (i) := Rand.Int (-4, 4)     x (i) := maxx div 2     y (i) := maxy div 2 end for setscreen ("offscreenonly") cls loop     cls     for k : 1 .. howmany         x (k) += dx (k)         y (k) += dy (k)         Draw.FillOval (x (k), y (k), 5, 5, brightred)         if x (k) >= maxx or x (k) <= 0 then             dx (k) := -dx (k)         elsif y (k) >= maxy or y (k) <= 0 then             dy (k) := -dy (k)         end if     end for     View.Update     delay (5) end loop

here's a little something to make that look better:
 code: var howmany : int put "How many balls? : " .. get howmany var x, y, dx, dy,a : array 1 .. howmany of real for i : 1 .. howmany     dx (i) := Rand.Int (-4, 4)     dy (i) := Rand.Int (-4, 4)     a (i) := Rand.Int (0, 100)/100     x (i) := maxx div 2     y (i) := maxy div 2 end for setscreen ("offscreenonly") cls loop     cls     for k : 1 .. howmany         x (k) += dx (k)*a(k)         y (k) += dy (k)*a(k)         Draw.FillOval (round(x (k)), round(y (k)), 5, 5, brightred)         if x (k) >= maxx or x (k) <= 0 then             dx (k) := -dx (k)         elsif y (k) >= maxy or y (k) <= 0 then             dy (k) := -dy (k)         end if     end for     View.Update     delay (5) end loop
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First

Page 2 of 2  [ 29 Posts ]
Goto page Previous  1, 2
 Jump to:  Select a forum  CompSci.ca ------------ - Network News - General Discussion     General Forums   -----------------   - Hello World   - Featured Poll   - Contests     Contest Forums   -----------------   - DWITE   - [FP] Contest 2006/2008   - [FP] 2005/2006 Archive   - [FP] 2004/2005 Archive   - Off Topic     Lounges   ---------   - User Lounge   - VIP Lounge     Programming -------------- - General Programming     General Programming Forums   --------------------------------   - Functional Programming   - Logical Programming   - C     C   --   - C Help   - C Tutorials   - C Submissions   - C++     C++   ----   - C++ Help   - C++ Tutorials   - C++ Submissions   - Java     Java   -----   - Java Help   - Java Tutorials   - Java Submissions   - Ruby     Ruby   -----   - Ruby Help   - Ruby Tutorials   - Ruby Submissions   - Turing     Turing   --------   - Turing Help   - Turing Tutorials   - Turing Submissions   - PHP     PHP   ----   - PHP Help   - PHP Tutorials   - PHP Submissions   - Python     Python   --------   - Python Help   - Python Tutorials   - Python Submissions   - Visual Basic and Other Basics     VB   ---   - Visual Basic Help   - Visual Basic Tutorials   - Visual Basic Submissions     Education ----------- - Student Life   Graphics and Design ----------------------- - Web Design     Web Design Forums   ---------------------   - (X)HTML Help   - (X)HTML Tutorials   - Flash MX Help   - Flash MX Tutorials   - Graphics     Graphics Forums   ------------------   - Photoshop Tutorials   - The Showroom   - 2D Graphics   - 3D Graphics     Teams ------ - dTeam Public

 Style: Appalachia blueSilver eMJay subAppalachia subBlue subCanvas subEmjay subGrey subSilver subVereor Search: