grad()

FASTLED_FORCE_INLINE fl::i32 fl::perlin_q16::grad ( int hash, fl::i32 x, fl::i32 y )

staticprivate

Definition at line 87 of file perlin_q16.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 g.cx * x + g.cy * y;
}

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