from_image() [1/2]

void MayaFlux::Kakshya::TextureContainer::from_image	(	const std::shared_ptr< Core::VKImage > &	image,
		const std::shared_ptr< Buffers::VKBuffer > &	staging,
		uint32_t	layer = 0
	)

Download pixel data from a VKImage, reusing a caller-supplied persistent staging buffer.

Identical to from_image() but passes staging through to TextureLoom::download_data, eliminating the per-call Vulkan object allocation. Use Buffers::create_image_staging_buffer(byte_size()) to allocate the staging buffer once before the render loop.

Parameters

image	Source GPU texture. Must be initialised and match dimensions.
staging	Host-visible staging VKBuffer sized to at least byte_size().
layer	Array layer index (default 0).

Definition at line 278 of file TextureContainer.cpp.

{
    if (!image || !image->is_initialized()) {
        MF_ERROR(Journal::Component::Kakshya, Journal::Context::ContainerProcessing,
            "TextureContainer::from_image(staging) called with uninitialised image");
        return;
    }
 
    if (layer >= m_data.size()) {
        MF_ERROR(Journal::Component::Kakshya, Journal::Context::ContainerProcessing,
            "TextureContainer::from_image(staging) layer {} out of range ({})", layer, m_data.size());
        return;
    }
 
    const size_t sz = byte_size();
    const size_t element_count = static_cast<size_t>(m_width) * m_height * m_channels;
 
    {
        Memory::SeqlockWriteGuard g(m_slot_locks[layer]);
        m_data[layer] = make_empty_storage(m_format, element_count);
        auto [ptr, bytes] = variant_bytes_mut(m_data[layer]);
        if (!ptr || bytes != sz) {
            MF_ERROR(Journal::Component::Kakshya, Journal::Context::ContainerProcessing,
                "TextureContainer::from_image(staging) variant size mismatch ({} vs {})", bytes, sz);
            return;
        }
        TextureLoom::instance().download_data(image, ptr, sz, staging);
    }
 
    m_normalised_dirty[layer].store(true, std::memory_order_release);
    update_processing_state(ProcessingState::READY);
}

References image, MF_ERROR, and ptr.