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 217 of file bitswap.h.

217 {
218 uint32_t x, y, t;
219
220 // Load the array and pack it into x and y.
221 y = *(unsigned int*)(A);
222 x = *(unsigned int*)(A+4);
223
224 // pre-transform x
225 t = (x ^ (x >> 7)) & 0x00AA00AA; x = x ^ t ^ (t << 7);
226 t = (x ^ (x >>14)) & 0x0000CCCC; x = x ^ t ^ (t <<14);
227
228 // pre-transform y
229 t = (y ^ (y >> 7)) & 0x00AA00AA; y = y ^ t ^ (t << 7);
230 t = (y ^ (y >>14)) & 0x0000CCCC; y = y ^ t ^ (t <<14);
231
232 // final transform
233 t = (x & 0xF0F0F0F0) | ((y >> 4) & 0x0F0F0F0F);
234 y = ((x << 4) & 0xF0F0F0F0) | (y & 0x0F0F0F0F);
235 x = t;
236
237 B[7] = y; y >>= 8;
238 B[6] = y; y >>= 8;
239 B[5] = y; y >>= 8;
240 B[4] = y;
241
242 B[3] = x; x >>= 8;
243 B[2] = x; x >>= 8;
244 B[1] = x; x >>= 8;
245 B[0] = x; /* */
246}
uint32_t x[NUM_LAYERS]
Definition Fire2023.ino:80
uint32_t y[NUM_LAYERS]
Definition Fire2023.ino:81

References FASTLED_FORCE_INLINE, x, and y.