Function createDFDAlpha

external/dfdutils/createdfd.c:787–809

* @~English * @brief Create a Data Format Descriptor for an alpha-only format. * * @param bigEndian Set to 1 for big-endian byte ordering and 0 for little-endian byte ordering. * @param bytes The number of bytes per channel. * @param suffix Indicates the format suffix for the type. * * @return A data format descriptor in malloc'd data. The caller is responsible *

 *         for freeing the descriptor.
 **/
uint32_t *createDFDAlpha(int bigEndian, int bytes,
                         enum VkSuffix suffix) {
    uint32_t *DFD;
    int channel = 3; /* alpha channel */
    if (bigEndian) {
        int channelByte;
        /* Number of samples = number of channels * bytes per channel */
        DFD = writeHeader(bytes, bytes, suffix, i_COLOR);
        /* Loop over the bytes that constitute a channel */
        for (channelByte = 0; channelByte < bytes; ++channelByte) {
            writeSample(DFD, channelByte, channel,
                        8, 8 * (bytes - channelByte - 1),
                        channelByte == bytes-1, channelByte == 0, suffix);
        }
    } else { /* Little-endian */
        /* One sample per channel */
        DFD = writeHeader(1, bytes, suffix, i_COLOR);
        writeSample(DFD, 0, channel,
                    8 * bytes, 0,
                    1, 1, suffix);
    }
    return DFD;
}