random setPosition generater, using rand()

[mapPhil]

hi,

I was wondering how would you generate random positions between -100 to 0 as well as 800 to 900

for example this is the code I have
(*currentIter).SetPosition(rand()% -100+0, rand()% 600);

and it sets the sprites position between 100 and 0
and the code below sets the sprite position between 800 and 900

(*currentIter).SetPosition(rand()%800 + 900, rand()% 600);

The question is how can I randomly choose between the both of these lines of code?

i tried:

(*currentIter).SetPosition(rand()%(-100 + 0)||(800 + 900), rand()% 600);

but that didn't work.

[Laurent]

Code: [Select]

if (rand() % 2)
    line 1
else
    line 2

By the way, your second line is wrong, it will generate numbers between 900 and 1700. The correct code would be:

Code: [Select]

rand() % 100 + 800

The general formula is

Code: [Select]

rand() % range + minimum

Therefore your first line should be

Code: [Select]

rand() % 100 - 100
Even if yours is correct in C++, it is incorrect mathematically (modulo can't give negative results) and thus could be confusing.

[mapPhil]

That's great, didn't though that rand() % range + minimum was the formula I thought it was rand() % minimum + maximum.

Thanks for the quick reply