Bit Manipulation Failing D:

[Nestharus]

//works?? don't know
bool getBit(byte bits, int index) { return 1 == (bits & intToByte(1 << index)); }

//does not work
void setBit(byte bits, int index, bool value) {
    if (value) {
        bits = bits | intToByte(1 << index);
    }
    else {
        bits = bits & ~intToByte(1 << index);
    }
}

from http://stackoverflow.com/questions/4674006/set-specific-bit-in-byte

 

[Dr Super Good]

bool getBit(byte bits, int index) { return 1 == (bits & intToByte(1 << index)); }

Makes no sense to me.

You sure you did not mean...

bool getBit(byte bits, int index) {
    return (bits & intToByte(1 << index)) != 0;
}

In C everything that is not 0 evaluates true. For any index other than 0 that function would return false even if the bit was set using your function. The correct statement shown in my function tests if it is not equal to 0 mimicing how C evaluates logic.

Alternativly this should also work assuming sign bit is ignored when right shifting (>>> in some languages)...

bool getBit(byte bits, int index) {
    return (intToByte(bits >> index) & 1) == 1;
}

//does not work
void setBit(byte bits, int index, bool value) {
if (value) {
bits = bits | intToByte(1 << index);
}
else {
bits = bits & ~intToByte(1 << index);
}
}

Logicly it is fine.

What is confusing me is what on earth the "intToByte" function is... There does not seem to be a way to convert byte to int types in SC2?

 

[Nestharus]

What is confusing me is what on earth the "intToByte" function is... There does not seem to be a way to convert byte to int types in SC2?

byte intToBit(int i) { return i; }

Logicly it is fine.

Yet it doesn't work D:

In C everything that is not 0 evaluates true. For any index other than 0 that function would return false even if the bit was set using your function. The correct statement shown in my function tests if it is not equal to 0 mimicing how C evaluates logic.

I'm checking 1 bit, so it's value can only be either 0 or 1, so != 0 and == 1 are the same things.

 

[Dr Super Good]

I'm checking 1 bit, so it's value can only be either 0 or 1, so != 0 and == 1 are the same things.

You even understand what the bit opperators are doing? You are checking a single bit but not at bit 0 position. It might only be a single bit but if it is bit 6 then it has a value of 64 and not 1.

Yet it doesn't work D:

In what way?

byte intToBit(int i) { return i; }

That was not the functon I asked for... However I am guessing you are trying to say it is using some kind of type-casting return bug?

 

[Nestharus]

That was not the functon I asked for... However I am guessing you are trying to say it is using some kind of type-casting return bug?

No, that is the exact function I am using, lol...

In what way?

In that when I set a bit to true for byte = 0, the byte is still 0.

edit
nvm, I'm being stupid, nvm nvm