bit_spread_lut.hpp

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#pragma once
 
#include "fl/stl/compiler_control.h"
#include "fl/stl/int.h"
 
namespace fl {
namespace detail {

constexpr u32 kSpreadNibble[16] = {
    0x00000000u, 0x01000000u, 0x00010000u, 0x01010000u,
    0x00000100u, 0x01000100u, 0x00010100u, 0x01010100u,
    0x00000001u, 0x01000001u, 0x00010001u, 0x01010001u,
    0x00000101u, 0x01000101u, 0x00010101u, 0x01010101u,
};

FASTLED_FORCE_INLINE u32 spreadA(u8 v) { return kSpreadNibble[v >> 4]; }
FASTLED_FORCE_INLINE u32 spreadB(u8 v) { return kSpreadNibble[v & 0x0Fu]; }

FASTLED_FORCE_INLINE FL_IRAM FL_OPTIMIZE_FUNCTION
void spread_transpose16_symbol(const u8 l[16], u8 out[16]) {
    const u32 aLo = spreadA(l[0]) | spreadA(l[1]) << 1 | spreadA(l[2]) << 2 | spreadA(l[3]) << 3 |
                    spreadA(l[4]) << 4 | spreadA(l[5]) << 5 | spreadA(l[6]) << 6 | spreadA(l[7]) << 7;
    const u32 bLo = spreadB(l[0]) | spreadB(l[1]) << 1 | spreadB(l[2]) << 2 | spreadB(l[3]) << 3 |
                    spreadB(l[4]) << 4 | spreadB(l[5]) << 5 | spreadB(l[6]) << 6 | spreadB(l[7]) << 7;
    const u32 aHi = spreadA(l[8]) | spreadA(l[9]) << 1 | spreadA(l[10]) << 2 | spreadA(l[11]) << 3 |
                    spreadA(l[12]) << 4 | spreadA(l[13]) << 5 | spreadA(l[14]) << 6 | spreadA(l[15]) << 7;
    const u32 bHi = spreadB(l[8]) | spreadB(l[9]) << 1 | spreadB(l[10]) << 2 | spreadB(l[11]) << 3 |
                    spreadB(l[12]) << 4 | spreadB(l[13]) << 5 | spreadB(l[14]) << 6 | spreadB(l[15]) << 7;
    out[0] = static_cast<u8>(aLo);        out[1] = static_cast<u8>(aHi);
    out[2] = static_cast<u8>(aLo >> 8);   out[3] = static_cast<u8>(aHi >> 8);
    out[4] = static_cast<u8>(aLo >> 16);  out[5] = static_cast<u8>(aHi >> 16);
    out[6] = static_cast<u8>(aLo >> 24);  out[7] = static_cast<u8>(aHi >> 24);
    out[8] = static_cast<u8>(bLo);        out[9] = static_cast<u8>(bHi);
    out[10] = static_cast<u8>(bLo >> 8);  out[11] = static_cast<u8>(bHi >> 8);
    out[12] = static_cast<u8>(bLo >> 16); out[13] = static_cast<u8>(bHi >> 16);
    out[14] = static_cast<u8>(bLo >> 24); out[15] = static_cast<u8>(bHi >> 24);
}

FASTLED_FORCE_INLINE FL_IRAM FL_OPTIMIZE_FUNCTION
void spread_transpose8_symbol(const u8 l[8], u8 out[8]) {
    const u32 a = spreadA(l[0]) | spreadA(l[1]) << 1 | spreadA(l[2]) << 2 | spreadA(l[3]) << 3 |
                  spreadA(l[4]) << 4 | spreadA(l[5]) << 5 | spreadA(l[6]) << 6 | spreadA(l[7]) << 7;
    const u32 b = spreadB(l[0]) | spreadB(l[1]) << 1 | spreadB(l[2]) << 2 | spreadB(l[3]) << 3 |
                  spreadB(l[4]) << 4 | spreadB(l[5]) << 5 | spreadB(l[6]) << 6 | spreadB(l[7]) << 7;
    out[0] = static_cast<u8>(a);        out[1] = static_cast<u8>(a >> 8);
    out[2] = static_cast<u8>(a >> 16);  out[3] = static_cast<u8>(a >> 24);
    out[4] = static_cast<u8>(b);        out[5] = static_cast<u8>(b >> 8);
    out[6] = static_cast<u8>(b >> 16);  out[7] = static_cast<u8>(b >> 24);
}
 
}  // namespace detail
}  // namespace fl