Multiple ball colision physics

[petree08]

Okay so a while a go i posted a ball physics thingy and it basically blew apple sauce.
So i went home ant wrote this little thing

it is sooo much better than my other one.

code:

const SIZE := 50 const MID_Y := maxy div 2 const MID_X := maxx div 2 const SPEED := 9 const SIZE_P := 10 const SIZE_C := 5 const DIV_F := 1 var X, Y, Dx, Dy, Sy, Sx, C : array 1 .. SIZE of int var Length : array 1 .. SIZE of real4 var Key : array char of boolean var XP, YP, Click : int setscreen ("graphics:max,max,nobuttonbar,offscreenonly") process Sound     sound (100, 100) end Sound for Index : 1 .. SIZE     randint (X (Index), 20, maxx - 20)     randint (Y (Index), 20, maxy - 20)     loop         randint (C (Index), 1, 15)         exit when C (Index) not= 7     end loop     Dx (Index) := 0     Dy (Index) := 0 end for XP := MID_X YP := MID_Y colorback (7) loop     drawfillbox (1, 1, maxx, maxy, 15)     drawfillbox (20, 20, maxx - 20, maxy - 20, 7)     mousewhere (XP, YP, Click)     drawfilloval (XP, YP, SIZE_P, SIZE_P, 0)     if Click = 1 then         for Index : 1 .. SIZE             Dx (Index) := 0             Dy (Index) := 0             % drawline (XP, YP, X (Index), Y (Index), 12)         end for         % else         %     for Index : 1 .. SIZE         %         %         drawline (XP, YP, X (Index), Y (Index), C (Index))         %     end for     end if     for Index : 1 .. SIZE         drawfilloval (X (Index), Y (Index), SIZE_C, SIZE_C, C (Index))         %drawfilloval (X (Index), Y (Index), SIZE_C, SIZE_C, 0)         if X (Index) > maxx - 20 or X (Index) < 20 then             Dx (Index) := -Dx (Index)         end if         if Y (Index) > maxy - 20 or Y (Index) < 20 then             Dy (Index) := -Dy (Index)         end if         Length (Index) := sqrt (((XP - X (Index)) ** 2) + ((YP - Y (Index)) ** 2))         if Length (Index) <= SIZE_C + SIZE_P then             %  fork Sound             Sy (Index) := - (YP - Y (Index))             Sx (Index) := - (XP - X (Index))             Dx (Index) := Sx (Index) div DIV_F             Dy (Index) := Sy (Index) div DIV_F         end if         for Index2 : 1 .. SIZE             Length (Index2) := sqrt (((X (Index2) - X (Index)) ** 2) + ((Y (Index2) - Y (Index)) ** 2))             if Length (Index2) <= SIZE_C + SIZE_C and Index not= Index2 then                 %fork Sound                 Sy (Index2) := Y (Index2) - Y (Index)                 Sx (Index2) := X (Index2) - X (Index)                 Dx (Index2) := Sx (Index2) div DIV_F                 Dy (Index2) := Sy (Index2) div DIV_F             end if             %drawline (X (Index), Y (Index), X (Index2), Y (Index2), 0)         end for         X (Index) := X (Index) + Dx (Index)         Y (Index) := Y (Index) + Dy (Index)     end for     View.Update end loop

[DemonZ]

Very Nice.... This would be useful for a pool game.

[Windsurfer]

The physics seem... weird. I'm going to be blunt here.
All the balls move at the same speed. It doesn't matter what angle their collisions are, they move at the same speed, just different directions. That's not proper.
Now for coding: Naming convention is nonexistent. In fact, some names are incorrect. "SIZE" should not be used to describe the number of balls, in my opinion. Also, although not a rule, it is common practice to name variables and arrays in all lowercase.
Don't use parallel arrays, use records instead.
Commenting should be used to explain code, not just disable a part of code.
...Good spacing. Keep that up.

[Cervantes]

The telltale clue that something is wrong here is that if you give the system a little bit of energy at the start of the program by jostling a few balls, then move the white ball into the corner, what happens? Eventually all the balls are moving pretty fast. There's a lot of energy in the system. Way more than you gave the system in the beginning.

[TripleBla]

Windsurfer wrote:

I am jesus.

fixed.

[blaster009]

Windsurfer wrote:

Now for coding: Naming convention is nonexistent. In fact, some names are incorrect. "SIZE" should not be used to describe the number of balls, in my opinion. Also, although not a rule, it is common practice to name variables and arrays in all lowercase.

Common for who? I use camelCase. I personally find it a lot easier to read xSizeArrayForBunchOfRandomObjects than xsizearrayforbunchofrandomobjects (of course, I'd never really use a name that long...)

As for size as the number, why not? It is HIS code, and if that's how he chooses to remember it, so be it.

[Clayton]

I think he meant variable names not as MyArray, but as myArray for example. SIZE just doesn't really explain what it is. To me it tells me how big something is (ie the radius of the ball).

EDIT: WOOHOO! 700th post