Given this Short (signed):
&Hxxxx
I want to:
- Extract the most right
&HxxFF
as SByte (signed) - Extract the left
&H7Fxx
as Byte (unsigned) - Identify if the most left
&H8xxx
is positive or negative (bool result)
Given this Short (signed):
&Hxxxx
I want to:
&HxxFF
as SByte (signed)&H7Fxx
as Byte (unsigned)&H8xxx
is positive or negative (bool result)( inline char getLsb(short s) { return s & 0xff; }
inline char getMsb(short s)
{
return (s & 0xff00) >> 8;
}
inline bool isBitSet(short s, unsigned pos)
{
return (s & (1 << pos)) > 0;
}
Extract the most right 0xxxff
myShort & 0x00FF
Extract the left 0xffxx
(myShort & 0xFF00) >> 8
Identify if the most left 0xfxxx is positive or negative (it's a signed short).
(myShort & 0xF000) >= 0;
Uh...
value & 0x00ff
(value & 0xff00) >> 8
(value & 0xf000) >= 0
EDIT: I suppose you want the byte value and not just the upper 8 bits.
Extract the most right &HxxFF as SByte (signed)
CType(s AND &H00FF, SByte)
Extract the left &H7Fxx as Byte (unsigned)
CType((s AND &H7F00) >> 8, Byte)
Identify if the most left &H8xxx is positive or negative (bool result)
s AND &H8000 > 0
I think those work, been a while since I have worked in VB
Dim test As UInt16 = &HD 'a test value 1101
Dim rb As Byte 'lsb
Dim lb As Byte 'msb - 7 bits
Dim rm As UInt16 = &HFF 'lsb mask
Dim lm As UInt16 = &H7F00 'msb mask
Dim sgn As Byte = &H80 'sign mask
For x As Integer = 0 To 15 'shift the test value one bit at a time
rb = CByte(test And rm) 'get lsb
lb = CByte((test And lm) >> 8) 'get msb
Dim lbS, rbS As Boolean 'sign
'set signs
If (rb And sgn) = sgn Then rbS = True _
Else rbS = False
If (lb And sgn) = sgn Then lbS = True _
Else lbS = False 'should always be false based on mask
Console.WriteLine(String.Format("{0} {1} {2} {3} {4}",
x.ToString.PadLeft(2, " "c),
Convert.ToString(lb, 2).PadLeft(8, "0"c),
Convert.ToString(rb, 2).PadLeft(8, "0"c),
lbS.ToString, rbS.ToString))
test = test << 1
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