grad()

FASTLED_FORCE_INLINE fl::i16 fl::perlin_s8x8::grad ( int hash, fl::i16 x, fl::i16 y )

staticprivate

Definition at line 86 of file perlin_s8x8.cpp.hpp.

                                                                                    {
    struct GradCoeff { fl::i8 cx; fl::i8 cy; };
    constexpr GradCoeff lut[16] = {
        { 1,  1}, {-1,  1}, { 1, -1}, {-1, -1},
        { 1,  0}, {-1,  0}, { 1,  0}, {-1,  0},
        { 0,  1}, { 0, -1}, { 0,  1}, { 0, -1},
        { 1,  1}, { 0, -1}, {-1,  1}, { 0, -1},
    };
    const GradCoeff &g = lut[hash & 15];
    return static_cast<fl::i16>(g.cx * x + g.cy * y);
}

References FASTLED_FORCE_INLINE, fl::FL_NO_EXCEPT, fl::g, fl::x, and fl::y.