to_image_array() [2/2]

std::shared_ptr< Core::VKImage > MayaFlux::Kakshya::TextureContainer::to_image_array

(

const std::shared_ptr< Buffers::VKBuffer > &

staging

)

const

Upload all layers as a Vulkan 2D array texture, reusing a staging buffer.

Concatenates pixel data from all layers in order (layer 0 first) and calls TextureLoom::create_2d_array. The returned VKImage has array_layers == get_layer_count() and an image view of type VK_IMAGE_VIEW_TYPE_2D_ARRAY, making it bindable as sampler2DArray in GLSL.

All layers must have been populated before calling this. Empty layers contribute zero bytes and will produce incorrect GPU data.

Parameters

staging

Host-visible staging VKBuffer sized to at least byte_size().

Returns

Initialised VKImage with array_layers > 1, or nullptr on failure.

Definition at line 315 of file TextureContainer.cpp.

{
    const auto n = static_cast<uint32_t>(m_data.size());
    if (n == 0)
        return nullptr;
 
    if (n == 1) {
        std::shared_ptr<Core::VKImage> img;
        seqlock_read_void(m_slot_locks[0], 8, [&] {
            auto [ptr, bytes] = variant_bytes(m_data[0]);
            if (!ptr || bytes == 0)
                return;
            auto& loom = TextureLoom::instance();
            img = loom.create_2d(m_width, m_height, m_format, nullptr);
            if (img)
                loom.upload_data(img, ptr, bytes, staging);
        });
        return img;
    }
 
    const size_t layer_bytes = byte_size();
    std::vector<uint8_t> combined(layer_bytes * n);
    for (uint32_t i = 0; i < n; ++i) {
        bool ok = seqlock_read_void(m_slot_locks[i], 8, [&] {
            auto [ptr, bytes] = variant_bytes(m_data[i]);
            if (!ptr || bytes != layer_bytes) {
                MF_ERROR(Journal::Component::Kakshya, Journal::Context::ContainerProcessing,
                    "TextureContainer::to_image_array(staging) layer {} size mismatch", i);
                return;
            }
            std::memcpy(combined.data() + i * layer_bytes, ptr, layer_bytes);
        });
 
        if (!ok)
            return nullptr;
    }
 
    auto& loom = TextureLoom::instance();
    auto img = loom.create_2d_array(m_width, m_height, n, m_format, nullptr);
    if (!img)
        return nullptr;
    loom.upload_data(img, combined.data(), combined.size(), staging);
    return img;
}

References MF_ERROR, ptr, and MayaFlux::Kakshya::variant_bytes().

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