Rotating a bitmap 90 degrees

Question

I have a one 64-bit integer, which I need to rotate 90 degrees in 8 x 8 area (preferably with straight bit-manipulation). I cannot figure out any handy algorith

Answer 1

If an if-powered loop is acceptable, the formula for bits is simple enough:

8>>Column - Row - 1

Column and Row are 0-indexed.

This gives you this mapping:

 7 15 23 31 39 47 55 63
 6 14 22 ...
 5 ...
 4 ...
 3 ...
 2 ...
 1 ...
 0  8 16 24 32 40 48 54 

Answer 2

probably something like that

for(int i = 0; i < 8; i++)
{
    for(int j = 0; j < 8; j++)
    {
        new_image[j*8+8-i] = image[i*8+j];
    }
}

Answer 3

v = (v & 0x000000000f0f0f0fUL) << 004 | (v & 0x00000000f0f0f0f0UL) << 040 |
    (v & 0xf0f0f0f000000000UL) >> 004 | (v & 0x0f0f0f0f00000000UL) >> 040;
v = (v & 0x0000333300003333UL) << 002 | (v & 0x0000cccc0000ccccUL) << 020 | 
    (v & 0xcccc0000cccc0000UL) >> 002 | (v & 0x3333000033330000UL) >> 020;
v = (v & 0x0055005500550055UL) << 001 | (v & 0x00aa00aa00aa00aaUL) << 010 | 
    (v & 0xaa00aa00aa00aa00UL) >> 001 | (v & 0x5500550055005500UL) >> 010;