mirror of https://github.com/axmolengine/axmol.git
97 lines
1.6 KiB
Lua
97 lines
1.6 KiB
Lua
-- bit operation
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bit = bit or {}
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bit.data32 = {}
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for i=1,32 do
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bit.data32[i]=2^(32-i)
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end
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function bit._b2d(arg)
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local nr=0
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for i=1,32 do
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if arg[i] ==1 then
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nr=nr+bit.data32[i]
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end
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end
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return nr
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end
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function bit._d2b(arg)
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arg = arg >= 0 and arg or (0xFFFFFFFF + arg + 1)
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local tr={}
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for i=1,32 do
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if arg >= bit.data32[i] then
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tr[i]=1
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arg=arg-bit.data32[i]
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else
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tr[i]=0
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end
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end
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return tr
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end
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function bit._and(a,b)
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local op1=bit._d2b(a)
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local op2=bit._d2b(b)
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local r={}
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for i=1,32 do
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if op1[i]==1 and op2[i]==1 then
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r[i]=1
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else
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r[i]=0
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end
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end
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return bit._b2d(r)
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end
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function bit._rshift(a,n)
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local op1=bit._d2b(a)
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n = n <= 32 and n or 32
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n = n >= 0 and n or 0
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for i=32, n+1, -1 do
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op1[i] = op1[i-n]
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end
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for i=1, n do
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op1[i] = 0
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end
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return bit._b2d(op1)
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end
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function bit._not(a)
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local op1=bit._d2b(a)
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local r={}
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for i=1,32 do
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if op1[i]==1 then
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r[i]=0
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else
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r[i]=1
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end
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end
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return bit._b2d(r)
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end
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function bit._or(a,b)
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local op1=bit._d2b(a)
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local op2=bit._d2b(b)
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local r={}
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for i=1,32 do
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if op1[i]==1 or op2[i]==1 then
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r[i]=1
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else
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r[i]=0
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end
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end
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return bit._b2d(r)
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end
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bit.band = bit.band or bit._and
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bit.rshift = bit.rshift or bit._rshift
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bit.bnot = bit.bnot or bit._not
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