Function writeSample

external/dfdutils/createdfd.c:105–172

}

static void writeSample(uint32_t *DFD, int sampleNo, int channel,
                        int bits, int offset,
                        int topSample, int bottomSample, enum VkSuffix suffix)
{
    // Use this to avoid type-punning complaints from the gcc optimizer
    // with -Wall.
    union {
        uint32_t i;
        float f;
    } lower, upper;
    uint32_t *sample = DFD + 1 + KHR_DF_WORD_SAMPLESTART + sampleNo * KHR_DF_WORD_SAMPLEWORDS;

    if (channel == 3) channel = KHR_DF_CHANNEL_RGBSDA_ALPHA;
    channel = setChannelFlags(channel, suffix);

    sample[KHR_DF_SAMPLEWORD_BITOFFSET] =
        (offset << KHR_DF_SAMPLESHIFT_BITOFFSET) |
        ((bits - 1) << KHR_DF_SAMPLESHIFT_BITLENGTH) |
        (channel << KHR_DF_SAMPLESHIFT_CHANNELID);

    sample[KHR_DF_SAMPLEWORD_SAMPLEPOSITION_ALL] = 0;

    switch (suffix) {
    case s_UNORM:
    case s_SRGB:
    default:
        if (bits > 32) {
            upper.i = 0xFFFFFFFFU;
        } else {
            upper.i = (uint32_t)((1U << bits) - 1U);
        }
        lower.i = 0U;
        break;
    case s_SNORM:
        if (bits > 32) {
            upper.i = 0x7FFFFFFF;
        } else {
            upper.i = topSample ? (1U << (bits - 1)) - 1 : (1U << bits) - 1;
        }
        lower.i = ~upper.i;
        if (bottomSample) lower.i += 1;
        break;
    case s_USCALED:
    case s_UINT:
        upper.i = bottomSample ? 1U : 0U;
        lower.i = 0U;
        break;
    case s_SSCALED:
    case s_SINT:
        upper.i = bottomSample ? 1U : 0U;
        lower.i = ~0U;
        break;
    case s_SFLOAT:
        upper.f = 1.0f;
        lower.f = -1.0f;
        break;
    case s_UFLOAT:
        upper.f = 1.0f;