collision help

[Undr_Xposed]

could someone plz help me understand collision better i only started to learn to about 2 weeks ago and can do very few things i get a bit of it but i want to fully understand it and i looked at the help for it and couldnt really make a whole lot of sense out of it

[TokenHerbz]

Well it works like this..

Each object has variables which tell it where it is on the map.

Now if we have an oval moving, say its chords at at X = 0, and y = 40

This means that the ball is infact on the border of the screen, we can detect this by:

code:

if ballx <= 0 then    %%We execute code, but this means its on the left border. end if

We can also set it for the top, bottom, or right of the screen by knowing how big our picture is, essentially its what you make it...

code:

setscreen("Graphics:300;300") %%or setscreen("Graphics:max;max")

Above we set the screen to its maximum space, or 300X300 screen, so to see a collistion, we would essentially do...

code:

if ballx+radius >= 300 then    %%we hit the right side end if %%you can also use maxx/maxy,  thats for maximum x and y length, though setscreen is of max/max.

we ADD the radius so that the outer part of the balls stoped, instead of the bottomleft x/y chords of the ball.

When we collide with other obsticles, especially from each and every way, we must cover all the angles.

bah im a horrible teacher... i cant really explain it

code:

setscreen("Graphics:max;max,offscreenonly") var square_x, square_y, square_size, square_vx, square_vy: array 1 .. 2 of int square_x(1) := 50 square_x(2) := 400 square_y(1) := 400 square_y(2) := 400 for i: 1 .. 2     square_vy(i) := 2     square_vx(i) := 2     square_size(i) := 40 end for loop     cls     for i: 1 .. 2         square_x(i) += square_vx(i)         square_y(i) += square_vy(i)     end for     if square_x(1) <= square_x(2)+square_size(2) and square_x(1)+square_size(1) >= square_x(2) and         square_y(1) <= square_y(2)+square_size(2) and square_y(1)+square_size(1) >= square_y(2) then         for i: 1 .. 2             square_vx(i) *= -1             square_vy(i) *= -1         end for     end if     for i : 1 .. 2         if square_x(i) <= 0 or square_x(i)+square_size(i) >= maxx then             square_vx(i) *= -1         end if         if square_y(i) <= 0 or square_y(i)+square_size(i) >= maxy then             square_vy(i) *= -1         end if     end for     drawfillbox(square_x(1),square_y(1),square_x(1)+square_size(1),square_y(1)+square_size(1),black)     drawfillbox(square_x(2),square_y(2),square_x(2)+square_size(2),square_y(2)+square_size(2),red)     View.Update     delay(5) end loop

[Undr_Xposed]

dont worry about beeing the greatest teacher i just need a basic outline that i can follow and learn form and that for the help greatly appriciated 8)

[Jekate]

I'm trying to learn this myself again, and was looking around for tuts on it. I'm not fully sure about it yet but it's coming back. I noticed though that when your balls hit, they reverse horizontal direction and vertical which isn't right so I made a guess and fixed it lol.

code:

setscreen("Graphics:max;max,offscreenonly") var square_x, square_y, square_size, square_vx, square_vy: array 1 .. 2 of int square_x(1) := 50 square_x(2) := 400 square_y(1) := 400 square_y(2) := 400 for i: 1 .. 2     square_vy(i) := 2     square_vx(i) := 2     square_size(i) := 40 end for loop     cls     for i: 1 .. 2         square_x(i) += square_vx(i)         square_y(i) += square_vy(i)     end for     if square_x(1) <= square_x(2)+square_size(2) and square_x(1)+square_size(1) >= square_x(2) and         square_y(1) <= square_y(2)+square_size(2) and square_y(1)+square_size(1) >= square_y(2) then         for i: 1 .. 2             square_vx(i) *= -1             square_vy(i) *= -1 %<------------------------- take this line out         end for     end if     for i : 1 .. 2         if square_x(i) <= 0 or square_x(i)+square_size(i) >= maxx then             square_vx(i) *= -1         end if         if square_y(i) <= 0 or square_y(i)+square_size(i) >= maxy then             square_vy(i) *= -1         end if     end for     drawfillbox(square_x(1),square_y(1),square_x(1)+square_size(1),square_y(1)+square_size(1),black)     drawfillbox(square_x(2),square_y(2),square_x(2)+square_size(2),square_y(2)+square_size(2),red)     View.Update     delay(5) end loop

I made reference to the text that should be taken out.