Main graph Node processor class. More...

#include <tracktion_Node.h>

Inheritance diagram for graph::Node:

Classes
struct	AudioAndMidiBuffer
	Contains the buffers for a processing operation. More...

struct	ProcessContext
	Struct to describe a single iteration of a process call. More...

struct	TransformOptions

Public Member Functions
	Node ()=default

virtual	~Node ()=default

void	initialise (const PlaybackInitialisationInfo &)
	Call once after the graph has been constructed to initialise buffers etc.

void	prepareForNextBlock (juce::Range< int64_t > referenceSampleRange)
	Call before processing the next block, used to reset the process status.

void	process (choc::buffer::FrameCount numSamples, juce::Range< int64_t > referenceSampleRange)
	Call to process the node, which will in turn call the process method with the buffers to fill.

bool	hasProcessed () const
	Returns true if this node has processed and its outputs can be retrieved.

AudioAndMidiBuffer	getProcessedOutput ()
	Returns the processed audio and MIDI output.

bool	canShareOutputBuffer () const
	Returns true if downstream Nodes may adopt this Node's output buffer as their own process buffer, overwriting its contents.

virtual TransformResult	transform (TransformOptions &)
	Called after construction to give the node a chance to modify its topology.

virtual std::vector< Node * >	getDirectInputNodes ()
	Should return all the inputs directly feeding in to this node.

virtual std::vector< Node * >	getInternalNodes ()
	Can return Nodes that are internal to this Node but don't make up the main graph constructed from getDirectInputNodes().

virtual NodeProperties	getNodeProperties ()=0
	Should return the properties of the node.

virtual bool	isReadyToProcess ()=0
	Should return true when this node is ready to be processed.

void	retain ()
	Retains the buffers so they won't be deallocated after the Node has processed.

void	release ()
	Releases the buffers allowing internal storage to be deallocated.

virtual size_t	getAllocatedBytes () const

void	enablePreProcess (bool)

Public Attributes
void *	internal = nullptr

int	numOutputNodes = -1

Protected Member Functions
virtual void	prepareToPlay (const PlaybackInitialisationInfo &)
	Called once before playback begins for each node.

virtual void	prefetchBlock (juce::Range< int64_t >)
	Called before once on all Nodes before they are processed.

virtual void	process (ProcessContext &)=0
	Called when the node is to be processed.

virtual void	preProcess (choc::buffer::FrameCount, juce::Range< int64_t >)
	Called when the node is to be processed, just before process.

void	setOptimisations (NodeOptimisations)
	This can be called to provide some hints about allocating or playing back a Node to improve efficiency.

void	setBufferViewToUse (Node *sourceNode, const choc::buffer::ChannelArrayView< float > &)
	This can be called during prepareToPlay to set a BufferView to use which can improve efficiency.

void	setAudioOutput (Node *sourceNode, const choc::buffer::ChannelArrayView< float > &)
	This can be called during your process function to set a view to the output.

Detailed Description

Main graph Node processor class.

Nodes are combined together to form a graph with a root Node which can then be initialsed and processed.

Subclasses should implement the various virtual methods but never call these directly. They will be called automatically by the non-virtual methods.

Constructor & Destructor Documentation

◆ Node()

graph::Node::Node ( )

default

◆ ~Node()

virtual graph::Node::~Node ( )

virtualdefault

Member Function Documentation

◆ initialise()

void Node::initialise ( const PlaybackInitialisationInfo & info )

Call once after the graph has been constructed to initialise buffers etc.

References graph::PlaybackInitialisationInfo::allocateAudioBuffer, graph::PlaybackInitialisationInfo::blockSize, and graph::PlaybackInitialisationInfo::deallocateAudioBuffer.

◆ prepareForNextBlock()

void Node::prepareForNextBlock ( juce::Range< int64_t > referenceSampleRange )

Call before processing the next block, used to reset the process status.

◆ process() [1/2]

void Node::process	(	choc::buffer::FrameCount	numSamples,
		juce::Range< int64_t >	referenceSampleRange
	)

Call to process the node, which will in turn call the process method with the buffers to fill.

Parameters

numSamples	The number of samples that need to be processed.
referenceSampleRange	The monotonic stream time in samples. This will be passed to the ProcessContext during the process callback so nodes can use this to determine file reading positions etc. Some nodes may ignore this completely. N.B. the length of this may be different to the number of samples to be processed so don't rely on them being the same!

◆ hasProcessed()

bool Node::hasProcessed ( ) const

Returns true if this node has processed and its outputs can be retrieved.

◆ getProcessedOutput()

Node::AudioAndMidiBuffer Node::getProcessedOutput ( )

Returns the processed audio and MIDI output.

Must only be called after hasProcessed returns true.

◆ canShareOutputBuffer()

bool Node::canShareOutputBuffer ( ) const

Returns true if downstream Nodes may adopt this Node's output buffer as their own process buffer, overwriting its contents.

This is the default but Nodes whose buffer contents must persist between blocks can opt out with ShareOutputBuffer::no.

See also: setOptimisations, setBufferViewToUse

References graph::NodeOptimisations::share.

◆ transform()

virtual TransformResult graph::Node::transform ( TransformOptions & )

virtual

Called after construction to give the node a chance to modify its topology.

This should return true if any changes were made to the topology as this indicates that the method may need to be called again after other nodes have had their toplogy changed.

Returns: TransformResult The type of transformation that has taken place. If connections have been made AND nodes deleted, return nodesDeleted

Reimplemented in graph::ConnectedNode, graph::SummingNode, and graph::ReturnNode.

◆ getDirectInputNodes()

virtual std::vector< Node * > graph::Node::getDirectInputNodes ( )

virtual

Should return all the inputs directly feeding in to this node.

Reimplemented in graph::ConnectedNode, graph::LatencyNode, graph::SummingNode, graph::BasicSummingNode, graph::FunctionNode, graph::GainNode, graph::SendNode, graph::ReturnNode, and graph::SinkNode.

Referenced by graph::test_utilities::logGraph(), graph::node_player_utils::reserveAudioBufferPool(), graph::detail::VisitNodesWithRecordBFS::visit(), and graph::detail::VisitNodesWithRecord::visit().

◆ getInternalNodes()

virtual std::vector< Node * > graph::Node::getInternalNodes ( )

virtual

Can return Nodes that are internal to this Node but don't make up the main graph constructed from getDirectInputNodes().

Most uses cases won't need to implement this but it could be used in situations where sub-graphs are created and processed internally to a Node but other Nodes in a graph still need to have access to them. This call can make them visible.

Referenced by graph::addNodesRecursive().

◆ getNodeProperties()

virtual NodeProperties graph::Node::getNodeProperties ( )

pure virtual

Should return the properties of the node.

This should not be called until after initialise.

Implemented in engine::WaveNodeRealTime, graph::ConnectedNode, graph::LatencyNode, graph::SummingNode, graph::MidiNode, graph::SinNode, graph::SilentNode, graph::BasicSummingNode, graph::FunctionNode, graph::GainNode, graph::SendNode, graph::ReturnNode, and graph::SinkNode.

Referenced by graph::addNodesRecursive(), and graph::node_player_utils::reserveAudioBufferPool().

◆ isReadyToProcess()

virtual bool graph::Node::isReadyToProcess ( )

pure virtual

Should return true when this node is ready to be processed.

This is usually when its input's output buffers are ready.

Implemented in engine::WaveNodeRealTime, graph::ConnectedNode, graph::LatencyNode, graph::SummingNode, graph::MidiNode, graph::SinNode, graph::SilentNode, graph::BasicSummingNode, graph::FunctionNode, graph::GainNode, graph::SendNode, graph::ReturnNode, and graph::SinkNode.

◆ retain()

void Node::retain ( )

Retains the buffers so they won't be deallocated after the Node has processed.

You shouldn't normally need to call this unles your Node player has special requirements.

Referenced by setAudioOutput(), and setBufferViewToUse().

◆ release()

void Node::release ( )

Releases the buffers allowing internal storage to be deallocated.

You shouldn't normally need to call this unles your Node player has special requirements.

◆ getAllocatedBytes()

size_t Node::getAllocatedBytes ( ) const

virtual

◆ enablePreProcess()

void graph::Node::enablePreProcess ( bool )

◆ prepareToPlay()

virtual void graph::Node::prepareToPlay ( const PlaybackInitialisationInfo & )

protectedvirtual

Called once before playback begins for each node.

Use this to allocate buffers etc. This step can be used to modify the topology of the graph (i.e. add/remove nodes). However, if you do this, you must make sure to call initialise on them so they are fully prepared for processing.

Reimplemented in engine::WaveNodeRealTime, graph::ConnectedNode, graph::LatencyNode, graph::SummingNode, graph::MidiNode, graph::SinNode, and graph::SilentNode.

◆ prefetchBlock()

virtual void graph::Node::prefetchBlock ( juce::Range< int64_t > )

protectedvirtual

Called before once on all Nodes before they are processed.

This can be used to prefetch audio data or update mute statuses etc..

◆ process() [2/2]

virtual void graph::Node::process ( ProcessContext & )

protectedpure virtual

Called when the node is to be processed.

This should add in to the buffers available making sure not to change their size at all.

Implemented in engine::WaveNodeRealTime, graph::ConnectedNode, graph::SinkNode, graph::LatencyNode, graph::SummingNode, graph::MidiNode, graph::SinNode, graph::SilentNode, graph::BasicSummingNode, graph::FunctionNode, graph::GainNode, graph::SendNode, and graph::ReturnNode.

◆ preProcess()

virtual void graph::Node::preProcess	(	choc::buffer::FrameCount	,
		juce::Range< int64_t >
	)

protectedvirtual

Called when the node is to be processed, just before process.

You shouldn't normally have to use this but it gives Nodes an opportunity to perform optimisations like steal input buffers from source if appropriate.

Reimplemented in graph::ReturnNode.

◆ setOptimisations()

void Node::setOptimisations ( NodeOptimisations newOptimisations )

protected

This can be called to provide some hints about allocating or playing back a Node to improve efficiency.

Be careful with these as they change the default and often expected behaviour.

◆ setBufferViewToUse()

void Node::setBufferViewToUse	(	Node *	sourceNode,
		const choc::buffer::ChannelArrayView< float > &	view
	)

protected

This can be called during prepareToPlay to set a BufferView to use which can improve efficiency.

Be careful with this. It's intended to use an input buffer as the internal buffer for this Node but that can only be done if the input Node only has a single output (or this Node doesn't write to it).

References retain().

◆ setAudioOutput()

void Node::setAudioOutput	(	Node *	sourceNode,
		const choc::buffer::ChannelArrayView< float > &	newAudioView
	)

protected

This can be called during your process function to set a view to the output.

This is useful to avoid having to allocate an internal buffer and always fill it if you're just passing on data.

References retain().

Member Data Documentation

◆ internal

void* graph::Node::internal = nullptr

◆ numOutputNodes

int graph::Node::numOutputNodes = -1

The documentation for this class was generated from the following file:

tracktion_Node.h

Classes

Public Member Functions

Public Attributes

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Node()

◆ ~Node()

Member Function Documentation

◆ initialise()

◆ prepareForNextBlock()

◆ process() [1/2]

◆ hasProcessed()

◆ getProcessedOutput()

◆ canShareOutputBuffer()

◆ transform()

◆ getDirectInputNodes()

◆ getInternalNodes()

◆ getNodeProperties()

◆ isReadyToProcess()

◆ retain()

◆ release()

◆ getAllocatedBytes()

◆ enablePreProcess()

◆ prepareToPlay()

◆ prefetchBlock()

◆ process() [2/2]

◆ preProcess()

◆ setOptimisations()

◆ setBufferViewToUse()

◆ setAudioOutput()

Member Data Documentation

◆ internal

◆ numOutputNodes