Computer Science Canada :: View topic - Circular Collision Detection- HELP!

var answer : string (1)
var down : string := chr (208)
var up : string := chr (200)
var left : string := chr (203)
var right : string := chr (205)

var userxlocation : int := maxx div 2
var userylocation : int := maxy div 2

var foo : int := 0

process user
loop
drawfilloval (userxlocation, userylocation, 20, 20, 48) %draw user
getch (answer)
if answer = up then %arrow key moves up
userylocation := userylocation + 18
if userylocation > maxy - 18 then
userylocation := maxy - 18
end if
elsif answer = down then %arrow key moves down
userylocation := userylocation - 18
if userylocation < 18 then
userylocation := 18
end if
elsif answer = left then %arrow key moves left
userxlocation := userxlocation - 18
if userxlocation < 18 then
userxlocation := 18
end if
elsif answer = right then %arrow key moves right
userxlocation := userxlocation + 18
if userxlocation > maxx - 18 then
userxlocation := maxx - 18
end if
end if
delay (10)
cls
drawfilloval (userxlocation, userylocation, 20, 20, 48) %redraw
end loop
end user

process enemy1
for i : 1 .. maxx
drawfilloval (100 + i, 100, 60, 60, blue)
delay (1)
drawfilloval (100 + i, 100, 60, 60, black)
end for
cls
for decreasing i : maxx .. 1
drawfilloval (100 + i, 100, 60, 60, blue)
delay (1)
drawfilloval (100 + i, 100, 60, 60, black)
foo := i
end for
end enemy1

setscreen ("graphics:max;max,nobuttonbar")
View.Set ("position:0;0")

colourback (black)
cls
View.Update

loop
cls
View.Update
fork user
delay (1020)
fork enemy1
delay (1060)
fork user
delay (1750)
View.Update

%40 is the radii of both circles added together
if sqrt ((userxlocation - (100 + foo)) ** 2 + (userylocation - 100) ** 2) <= 40 then
cls
put "GAME OVER"
exit
end if

end loop
put "IT IS ENDED"

Author:	Dreadnought [ Thu May 30, 2013 8:24 pm ]
Post subject:	Re: Circular Collision Detection- HELP!
First and foremost I strongly recommend that you do not use processes. I understand it's tempting, but it will likely cause you more grief than good. Why are you calling fork over and over again? You don't need multiple user and enemy1 processes, one will suffice (note that I think you would be better off not using processes). As for why your game is not exiting, you check for collision once every 1.83 seconds and when you do foo is probably 1. Instead of using processes, try keeping track of where your objects are, where they are going, then run a loop to update where they are on the screen and check for collision every time.

Author:	evildaddy911 [ Fri May 31, 2013 6:24 pm ]
Post subject:	RE:Circular Collision Detection- HELP!
the biggest 2 things wrong with it are: 1. you should have put your "fork" statements OUTSIDE the main loop if you are using processes (which should NOT be used in Turing) because then you start a new process every few seconds, which generally just blows up your program 2. when you exit the main loop because the player has collided with the ball of death, you don't end the processes. that is why processes are bad. they don't end until either they run out of code to execute or the program ends. as far as i know, there is only 1 way to end a process prematurely: by putting "exit when done" statement ONLY inside the biggest loop of the process. What i suggest doing is incorporating the processes into 1 big main loop. have player movement, then ball-of-death movement. then have your "am i dead?" check, exiting if neccesary. No processes. 1 more thing: when you use setscreen and View.Set, you aren't switching the drawing mode to "offscreenonly" so View.Update is doing nothing. if you don't understand what this means, check out the Turing Walkthrough