Method alloc

src/libOpenImageIO/imageio.cpp:750–774

void
DeepData::alloc ()
{
    // Calculate the total size we need, align each channel to 4 byte boundary
    size_t totalsamples = 0, totalbytes = 0;
    for (int i = 0;  i < npixels;  ++i) {
        int s = nsamples[i];
        totalsamples += s;
        for (int c = 0;  c < nchannels;  ++c)
            totalbytes += round_to_multiple (channeltypes[c].size() * s, 4);
    }

    // Set all the data pointers to the right offsets within the
    // data block.  Leave the pointes NULL for pixels with no samples.
    data.resize (totalbytes);
    char *p = &data[0];
    for (int i = 0;  i < npixels;  ++i) {
        if (nsamples[i]) {
            for (int c = 0;  c < nchannels;  ++c) {
                pointers[i*nchannels+c] = p;
                p += round_to_multiple (channeltypes[c].size()*nsamples[i], 4);
            }
        }
    }
}