feed() [2/2]

void MayaFlux::Buffers::ShaderProcessor::feed	(	const std::string &	name,
		FeedSource	source,
		uint32_t	offset,
		size_t	size = sizeof(float),
		bool	early = true
	)

Supply a push constant from a callable at an explicit offset.

Parameters

name	Logical name, used for removal and error reporting. Need not match anything on the shader.
source	Callable returning a double or a GpuValue.
offset	Byte offset in the push constant block.
size	Byte width written for a double. Four narrows to float, eight keeps double. Other values are rejected. A GpuValue writes its own width and ignores this.
early	True writes at the top of processing_function. False writes after the final on_before_execute of a compute dispatch, which is the only way a value survives a processor that rewrites its whole push constant block there. Other dispatch kinds ignore false.

The form hand-written shaders need, since their push constant block is described nowhere the processor can read.

Definition at line 265 of file ShaderProcessor.cpp.

{
    if (!source) {
        MF_ERROR(Journal::Component::Buffers, Journal::Context::BufferProcessing,
            "feed: null source for '{}'", name);
        return;
    }
 
    if (size != sizeof(float) && size != sizeof(double)) {
        MF_ERROR(Journal::Component::Buffers, Journal::Context::BufferProcessing,
            "feed: '{}' requests {} bytes, only 4 or 8 are written", name, size);
        return;
    }
 
    auto& entry = m_feeds[name];
    entry.source = std::move(source);
    entry.is_storage = false;
    entry.offset = offset;
    entry.size = size;
    entry.format.reset();
    entry.descriptor_name.clear();
    entry.buffer.reset();
    entry.mismatch_logged = false;
    entry.early = early;
}

References MayaFlux::Journal::BufferProcessing, MayaFlux::Journal::Buffers, m_feeds, MF_ERROR, name, offset, and size.