Collision Detection and Bounces

[JumpingLimaBean]

Im looking to make a game of tag.


There is a circle and a square.

You start at opposite corners and you cant go outside of the window.
Whoever is "red" color has to chase after the other "your it" and when you
tag them you get 1 point. When you tag them, they then become "red", "it"
and they chase after you. First to 10 points wins







Turing
----------
%%%%%%%%%%%boundries%%%%%%%%
if bally > 380 then
bally := 380
boxY := 370
end if
if bally < 20 then
bally := 20
boxY :=10
end if
if ballx > 620 then
ballx := 620
boxX := 610
end if
if ballx < 20 then
ballx := 20
boxX := 10
end if

if boxy > 360 then
boxy := 360
end if
if boxy < 0 then
boxy := 0
end if
if boxx > 600 then
boxx := 600
end if
if boxx < 0 then
boxx := 0
end if



That is used in a program to create boundaries between a circle and a square. When they touch eachother a point is then sent.
How is this used? I dont understand what the 360 and that means. Help please xD

[Raknarg]

This is just used to make sure that the shape can't escape the boundaries. If it's past the boundaries, it puts it back on the edge.

[JumpingLimaBean]

I dont get how this detects if the players touch
eachother and when they do, they reset to again starter positions can someone explain in simple form?

var ballx, bally :int :=300
var boxX,boxY :int :=290
var boxx,boxy :int :=50





Input.KeyDown (chars)
drawfillbox (maxx,maxy,0,0,black)
drawfillbox (boxX,boxY,boxX +20,boxY +20,black)
delay (3)
drawfilloval (ballx,bally,10,10,colour1)
delay (3)
drawfillbox (boxx,boxy,boxx +20,boxy +20,colour2)
delay (3)
t-=1
exit when t =0
View.Update





if colour1=40 and boxx < boxX +20 and boxx +20 > boxX and boxy < boxY +20 and boxy +20 > boxY then %?
colour1 :=0
colour2 :=40
boxx :=100
boxy :=100
score1 +=1
end if

if colour2=40 and boxX < boxx +20 and boxX +20 > boxx and boxY < boxy +20 and boxY +20 > boxy then %?
colour2 :=0
colour1 :=40
boxX :=290
boxY :=290
ballx :=300
bally :=300
score2 +=1
end if

[Zren]

Combining circle and rectangular collision detection is annoying (possible but annoying). Why not just make both of them circles but different colours? Maybe even draw a number inside them with Font.Draw?

Then read up on Collision detection here: http://compsci.ca/v3/viewtopic.php?t=13661

[JumpingLimaBean]

how would i get the number to stay in the cirlce tho


By the way thanks for the tip

[2F_Zelda]

You would have the location of the number dependent on the location of the shape.

[JumpingLimaBean]

how would i do that

[Tony]

You know where to draw the shape/circle; draw the number at the same location. Read the documentation on Font.Draw

[JumpingLimaBean]

I successfully drew the "1" in the same location of the circle. But how do i get it to follow with it

[JumpingLimaBean]

Okay i ended up doing this prgram.

I got collision to work, but the problem is
that im going to use it to make TAG. If i
move past the circle, it says negative value
passed to Sqrt. I need it not to do this.
And sometimes it goes into the circle and not
stopping so its detecting it late or something.
Please test out and help me make it better
so i can turn it into TAG.

Turing:

var x := 320 var y := 200 var circlex1, circley1, circlerad1 : int var circlex2, circley2, circlerad2 : int var distance : real var number : int circlex1 := 100 circley1 := 100 circlerad1 := 10 circlex2 := 250 circley2 := 220 circlerad2 := 30 const INCREMENT : int := 5 %this variable is needed to use Input.Keydown var chars : array char of boolean loop         cls         Draw.FillOval (circlex1, circley1, circlerad1, circlerad1, black)         Draw.FillOval (circlex2,circley2,circlerad2,circlerad2, 9)         Input.KeyDown (chars)  %tell computer to listen for keypresses                 %check arrow keys         %Look up Keyboard in the Turing reference to find all special         %key codes         if chars (KEY_LEFT_ARROW) and chars(KEY_UP_ARROW) then                 circlex1 := circlex1 - INCREMENT                 circley1 := circley1 + INCREMENT         elsif chars (KEY_RIGHT_ARROW) and chars(KEY_UP_ARROW) then                 circlex1 := circlex1 + INCREMENT                 circley1 := circley1 + INCREMENT         elsif chars (KEY_LEFT_ARROW) and chars(KEY_DOWN_ARROW) then                 circley1 := circley1 - INCREMENT                 circlex1 := circlex1 - INCREMENT         elsif chars (KEY_RIGHT_ARROW) and chars(KEY_DOWN_ARROW) then                 circley1 := circley1 - INCREMENT                 circlex1 := circlex1 + INCREMENT         elsif chars (KEY_LEFT_ARROW) then                 circlex1 := circlex1 - INCREMENT         elsif chars (KEY_RIGHT_ARROW) then                 circlex1 := circlex1 + INCREMENT         elsif chars (KEY_UP_ARROW) then                 circley1 := circley1 + INCREMENT         elsif chars (KEY_DOWN_ARROW) then                 circley1 := circley1 - INCREMENT         end if                                 %check asdf keys         if chars ('a') then                 circlex2 := circlex2 - INCREMENT         elsif chars ('d') then                 circlex2 := circlex2 + INCREMENT         elsif chars ('w') then                 circley2 := circley2 + INCREMENT         elsif chars ('s') then                 circley2 := circley2 - INCREMENT         end if         distance := sqrt (circlex2 - circlex1) ** 2 + (circley2 - circley1) ** 2                 if distance <= circlerad1 + circlerad2 then         put " Nice Kyle you mastered movable collision!"         exit         end if                 delay(20)  end loop

[JumpingLimaBean]

I will try to do the numbers in the circles tomorrow or something.

[Zren]

Quote:

distance := sqrt (circlex2 - circlex1) ** 2 + (circley2 - circley1) ** 2

Pythagorean Therum...

c^2 = a^2 + b^2
c = sqrt(a^2 + b^2)
dist = sqrt((x1-x2)^2 + (y1-y2)^2)

You missed the brackets foo.

[JumpingLimaBean]

Thanks i missed those. I tried adding bracket at end of 2 and it didnt work so i took it out. I was missing the bracket infront of sqrt xD


It now works.



Now how do i get a number 1 to stay in the circle and follow it O.o

I know i gotta place it in with the circle or something. Do i need to do some if statements

[2F_Zelda]

No, you want to draw it at the same co-ordinates as the circle.

[Raknarg]

So let me get this straight, are you trying to get something to rotate around a circle?