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Thread: Simple Bitwise Encoding and Reversing

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    Default Simple Bitwise Encoding and Reversing

    Sorry if wrong section / crap name.

    I have an index that is encoded as such:
    int idx = x << 11 | z << 7 | y;

    my question is: can i go from idx back to x, z, y?
    If so, how?
    If not.. crap.


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    Default Re: Simple Bitwise Encoding and Reversing

    can i go from idx back to x, z, y
    Yes. Use a paper and pencil to map where the bits in the int are from the original values of x,y,z
    To extract those values you will need to use a shift to move the bits to the low-order end of the int and an AND operation to 0 out all but the desired bits.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Simple Bitwise Encoding and Reversing

    You can do it but only if the values of x, y, and z once shifted, fit uniquely in a 32 bit integer without overlap or bit loss.

    Regards,
    Jim

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