Function ColorFromPalette

src/fl/gfx/colorutils.cpp.hpp:395–483

}

CRGB ColorFromPalette(const CRGBPalette16 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 239); // Blend range is affected by lo4 blend of
                                     // values, remap to avoid wrapping
    }

    //      hi4 = index >> 4;
    fl::u8 hi4 = lsrX4(index);
    fl::u8 lo4 = index & 0x0F;

    // const CRGB* entry = &(pal[0]) + hi4;
    // since hi4 is always 0..15, hi4 * sizeof(CRGB) can be a single-byte value,
    // instead of the two byte 'int' that avr-gcc defaults to.
    // So, we multiply hi4 X sizeof(CRGB), giving hi4XsizeofCRGB;
    fl::u8 hi4XsizeofCRGB = hi4 * sizeof(CRGB);
    // We then add that to a base array pointer.
    const CRGB *entry = (CRGB *)((fl::u8 *)(&(pal[0])) + hi4XsizeofCRGB);

    fl::u8 blend = lo4 && (blendType != NOBLEND);

    fl::u8 red1 = entry->red;
    fl::u8 green1 = entry->green;
    fl::u8 blue1 = entry->blue;

    if (blend) {

        if (hi4 == 15) {
            entry = &(pal[0]);
        } else {
            ++entry;
        }

        fl::u8 f2 = lo4 << 4;
        fl::u8 f1 = 255 - f2;

        //    rgb1.nscale8(f1);
        fl::u8 red2 = entry->red;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        red2 = scale8_LEAVING_R1_DIRTY(red2, f2);
        red1 += red2;

        fl::u8 green2 = entry->green;
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        green2 = scale8_LEAVING_R1_DIRTY(green2, f2);
        green1 += green2;

        fl::u8 blue2 = entry->blue;
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, f2);
        blue1 += blue2;

        cleanup_R1();
    }

    if (brightness != 255) {
        if (brightness) {
            ++brightness; // adjust for rounding