transpose8x1()

FASTLED_FORCE_INLINE void fl::transpose8x1	(	unsigned char *	A,
		unsigned char *	B )

Simplified 8x1 bit transpose (inline version)

Parameters

A	Input array (8 bytes)
B	Output array (8 bytes, transposed)

Examples

/home/runner/work/dox/dox/fastled/src/fl/math/transposition.h.

Definition at line 116 of file transposition.h.

                                                                                        {
    fl::u32 x, y, t;
 
    // Load the array and pack it into x and y.
    y = *(fl::u32*)(A);
    x = *(fl::u32*)(A+4);
 
    // pre-transform x
    t = (x ^ (x >> 7)) & 0x00AA00AA;  x = x ^ t ^ (t << 7);
    t = (x ^ (x >>14)) & 0x0000CCCC;  x = x ^ t ^ (t <<14);
 
    // pre-transform y
    t = (y ^ (y >> 7)) & 0x00AA00AA;  y = y ^ t ^ (t << 7);
    t = (y ^ (y >>14)) & 0x0000CCCC;  y = y ^ t ^ (t <<14);
 
    // final transform
    t = (x & 0xF0F0F0F0) | ((y >> 4) & 0x0F0F0F0F);
    y = ((x << 4) & 0xF0F0F0F0) | (y & 0x0F0F0F0F);
    x = t;
 
    *((u32*)B) = y;
    *((u32*)(B+4)) = x;
}

References B, FASTLED_FORCE_INLINE, FL_NO_EXCEPT, t, x, and y.