FastLED 3.9.15
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◆ transpose8x1_MSB()

FASTLED_FORCE_INLINE void transpose8x1_MSB ( unsigned char * A,
unsigned char * B )

Simplified form of bits rotating function.

Based on code found here: https://web.archive.org/web/20190108225554/http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt

Definition at line 219 of file bitswap.h.

219 {
220 uint32_t x, y, t;
221
222 // Load the array and pack it into x and y.
223 y = *(unsigned int*)(A);
224 x = *(unsigned int*)(A+4);
225
226 // pre-transform x
227 t = (x ^ (x >> 7)) & 0x00AA00AA; x = x ^ t ^ (t << 7);
228 t = (x ^ (x >>14)) & 0x0000CCCC; x = x ^ t ^ (t <<14);
229
230 // pre-transform y
231 t = (y ^ (y >> 7)) & 0x00AA00AA; y = y ^ t ^ (t << 7);
232 t = (y ^ (y >>14)) & 0x0000CCCC; y = y ^ t ^ (t <<14);
233
234 // final transform
235 t = (x & 0xF0F0F0F0) | ((y >> 4) & 0x0F0F0F0F);
236 y = ((x << 4) & 0xF0F0F0F0) | (y & 0x0F0F0F0F);
237 x = t;
238
239 B[7] = y; y >>= 8;
240 B[6] = y; y >>= 8;
241 B[5] = y; y >>= 8;
242 B[4] = y;
243
244 B[3] = x; x >>= 8;
245 B[2] = x; x >>= 8;
246 B[1] = x; x >>= 8;
247 B[0] = x; /* */
248}
int y
Definition Audio.ino:72
int x
Definition Audio.ino:71

References FASTLED_FORCE_INLINE, x, and y.