Thanks for the comments.
Quote:
Originally Posted by Y_Less
I would also point out this:
pawn Код:
#define Bit16_Get(%0,%1) (%0[(%1)>>>1]&(0x0000FFFF<<(((%1)&1)<<4)))
Directly based on the code in y_bits, which leads instantly on to:
pawn Код:
#define Bit4_Get(%0,%1) (%0[(%1)>>>3]&(0x0000000F<<(((%1)&7)<<2)))
As the basis of a nibble system.
In general (where "%2" is the size of data, only works with powers of 2). Note that this assumes a 32-bit cell size (the full generic solution is harder).
pawn Код:
#define BitX_Mask(%2) ((1 << (%2)) - 1)
#define BitX_Log(%2) log2(%2)
#define BitX_Shift(%2) (5 - BitX_Log(%2))
#define BitX_Filter(%2) ((1 << BitX_Shift(%2)) - 1)
#define BitX_Get(%0,%1,%2) (%0[(%1) >>> BitX_Shift(%2)] & (BitX_Mask(%2) << (((%1) & BitX_Filter(%2)) << BitX_Log(%2))))
I've added extra brackets for convenience, and you're best off pre-calculating bits. For reference, here is log2 (base 2 logarithm) for relevant values:
pawn Код:
1 = 0
2 = 1
4 = 2
8 = 3
16 = 4
32 = 5
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To be honest I don't understand, and I think I won't for some time... xD
