29 lines
939 B
C++
29 lines
939 B
C++
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#define FASTLED_INTERNAL
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#include "FastLED.h"
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/// Simplified form of bits rotating function. Based on code found here - http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt - rotating
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/// data into LSB for a faster write (the code using this data can happily walk the array backwards)
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void transpose8x1_noinline(unsigned char *A, unsigned char *B) {
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uint32_t x, y, t;
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// Load the array and pack it into x and y.
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y = *(unsigned int*)(A);
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x = *(unsigned int*)(A+4);
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// pre-transform x
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t = (x ^ (x >> 7)) & 0x00AA00AA; x = x ^ t ^ (t << 7);
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t = (x ^ (x >>14)) & 0x0000CCCC; x = x ^ t ^ (t <<14);
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// pre-transform y
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t = (y ^ (y >> 7)) & 0x00AA00AA; y = y ^ t ^ (t << 7);
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t = (y ^ (y >>14)) & 0x0000CCCC; y = y ^ t ^ (t <<14);
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// final transform
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t = (x & 0xF0F0F0F0) | ((y >> 4) & 0x0F0F0F0F);
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y = ((x << 4) & 0xF0F0F0F0) | (y & 0x0F0F0F0F);
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x = t;
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*((uint32_t*)B) = y;
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*((uint32_t*)(B+4)) = x;
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}
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