(C++) 'random' sequence generator

[bitplane]

output from rand() differs across systems even if you set the same seed, so I made this litle sequence generator to keep everything in sync
It may not be random enough for you though

Code: Select all

class CRandSequence
{
public:
    u32 A, B;

    CRandSequence::CRandSequence(u32 seeda, u32 seedb)
    {
        Set(seeda,seedb);
    }
    
    void CRandSequence::Set(u32 seeda, u32 seedb, u32 loops=0)
    {
        A = seeda+((u32)-1)/2;
        B = seedb+((u32)-1)/2;
        for (s32 n=0; n<loops; ++n) getInt();
    }
    
    // returns the next number in the sequence as a u32
    u32 CRandSequence::getInt()
    {
        u32 ret = A + B;
        A=B; B=ret;
        return ret;
    }
    // returns the next number in the sequence as a float 0.0 to 1.0
    f32 CRandSequence::getFloat()
    {
        u32 ret = A + B;
        A=B; B=ret;
        return (f32) ( (f64)ret/(f64)((u32)-1) );
    }
};

[Warchief]

output from rand() differs across systems even if you set the same seed

Are you totally sure about this? Im not saying you are wrong, im really asking if you are sure. Could it be just because of rand implementation in different libs?

[jam]

I was thinking he meant on different platforms(linux, windows, unix, etc)?