Thread: Fixed point opperations?

  1. #1
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    Fixed point opperations?

    hi!
    in my software renderer i managed some fixed point operations. this is pretty easy with SHL and SHR. but now that i want to implement new stuff to my polygon-fill-routine, i would have to change everything. but all i get is confuseness and errors because those fixed opperations are just to over complicated when i do it my way. is there a library or a class which supports them more effective? because they are two times faster than floats or int64... :/

  2. #2
    Dr Dipshi++ mike_g's Avatar
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    in my software renderer i managed some fixed point operations. this is pretty easy with SHL and SHR.
    Sounds like you made your own fixed point system in Blitz. If so you could always convert it to C++.

    SHL would be << and SHR is: >>

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    i know how the syntax looks like and i already converted it to c++ days ago.
    the point is: is there a 'system' that allows me to set up a fixed point integer with a constant number of bits behind the comma?

  4. #4
    and the hat of int overfl Salem's Avatar
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    There's almost certainly a fixed-point number class out there somewhere.

    Or you could write one yourself.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

  5. #5
    Dr Dipshi++ mike_g's Avatar
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    I never made my own fixed point system, but theres some C++ code for it on iMalcs site:

    http://homepages.ihug.co.nz/~aurora7...ul_Classes.htm

    Don't know if thats of any use to you.

  6. #6
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    ah so there is a library COOL
    i'll try this!
    thanks guys!

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