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Diffstat (limited to 'libs/ardour/ardour/port_engine.h')
| -rw-r--r-- | libs/ardour/ardour/port_engine.h | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/libs/ardour/ardour/port_engine.h b/libs/ardour/ardour/port_engine.h new file mode 100644 index 0000000000..71f93ea05e --- /dev/null +++ b/libs/ardour/ardour/port_engine.h @@ -0,0 +1,345 @@ +/* + Copyright (C) 2013 Paul Davis + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +*/ + +#ifndef __libardour_port_engine_h__ +#define __libardour_port_engine_h__ + +#include <vector> +#include <string> + +#include <stdint.h> + +#include "ardour/data_type.h" +#include "ardour/types.h" + +namespace ARDOUR { + +class PortManager; + +/** PortEngine is an abstract base class that defines the functionality + * required by Ardour. + * + * A Port is basically an endpoint for a datastream (which can either be + * continuous, like audio, or event-based, like MIDI). Ports have buffers + * associated with them into which data can be written (if they are output + * ports) and from which data can be read (if they input ports). Ports can be + * connected together so that data written to an output port can be read from + * an input port. These connections can be 1:1, 1:N OR N:1. + * + * Ports may be associated with software only, or with hardware. Hardware + * related ports are often referred to as physical, and correspond to some + * relevant physical entity on a hardware device, such as an audio jack or a + * MIDI connector. Physical ports may be potentially asked to monitor their + * inputs, though some implementations may not support this. + * + * Most physical ports will also be considered "terminal", which means that + * data delivered there or read from there will go to or comes from a system + * outside of the PortEngine implementation's control (e.g. the analog domain + * for audio, or external MIDI devices for MIDI). Non-physical ports can also + * be considered "terminal". For example, the output port of a software + * synthesizer is a terminal port, because the data contained in its buffer + * does not and cannot be considered to come from any other port - it is + * synthesized by its owner. + * + * Ports also have latency associated with them. Each port has a playback + * latency and a capture latency: + * + * <b>capture latency</b>: how long since the data read from the buffer of a + * port arrived at at a terminal port. The data will have + * come from the "outside world" if the terminal port is also + * physical, or will have been synthesized by the entity that + * owns the terminal port. + * + * <b>playback latency</b>: how long until the data written to the buffer of + * port will reach a terminal port. + * + * + * For more detailed questions about the PortEngine API, consult the JACK API + * documentation, on which this entire object is based. + */ + +class PortEngine { + public: + PortEngine (PortManager& pm) : manager (pm) {} + virtual ~PortEngine() {} + + /* We use void* here so that the API can be defined for any implementation. + * + * We could theoretically use a template (PortEngine<T>) and define + * PortHandle as T, but this complicates the desired inheritance + * pattern in which FooPortEngine handles things for the Foo API, + * rather than being a derivative of PortEngine<Foo>. + */ + + typedef void* PortHandle; + + /** Return a typeless pointer to an object that may be of interest + * that understands the internals of a particular PortEngine + * implementation. + * + * XXX the existence of this method is a band-aid over some design + * issues and will it will be removed in the future + */ + virtual void* private_handle() const = 0; + + virtual bool connected() const = 0; + + /** Return the name of this process as used by the port manager + * when naming ports. + */ + virtual const std::string& my_name() const = 0; + + /** Return the maximum size of a port name + */ + virtual uint32_t port_name_size() const = 0; + + /** Returns zero if the port referred to by @param port was set to @param + * name. Return non-zero otherwise. + */ + virtual int set_port_name (PortHandle port, const std::string& name) = 0; + /** Return the name of the port referred to by @param port. If the port + * does not exist, return an empty string. + */ + virtual std::string get_port_name (PortHandle) const = 0; + /** Return a reference to a port with the fullname @param name. Return + * a null pointer if no such port exists. + */ + virtual PortHandle* get_port_by_name (const std::string&) const = 0; + + /** Find the set of ports whose names, types and flags match + * specified values, place the names of each port into @param ports, + * and return the count of the number found. + * + * To avoid selecting by name, pass an empty string for @param + * port_name_pattern. + * + * To avoid selecting by type, pass DataType::NIL as @param type. + * + * To avoid selecting by flags, pass PortFlags (0) as @param flags. + */ + virtual int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>& ports) const = 0; + + /** Return the Ardour data type handled by the port referred to by @param + * port. Returns DataType::NIL if the port does not exist. + */ + virtual DataType port_data_type (PortHandle port) const = 0; + + /** Create a new port whose fullname will be the conjuction of my_name(), + * ":" and @param shortname. The port will handle data specified by @param + * type and will have the flags given by @param flags. If successfull, + * return a reference to the port, otherwise return a null pointer. + */ + virtual PortHandle register_port (const std::string& shortname, ARDOUR::DataType type, ARDOUR::PortFlags flags) = 0; + + /* Destroy the port referred to by @param port, including all resources + * associated with it. This will also disconnect @param port from any ports it + * is connected to. + */ + virtual void unregister_port (PortHandle) = 0; + + /* Connection management */ + + /** Ensure that data written to the port named by @param src will be + * readable from the port named by @param dst. Return zero on success, + * non-zero otherwise. + */ + virtual int connect (const std::string& src, const std::string& dst) = 0; + + /** Remove any existing connection between the ports named by @param src and + * @param dst. Return zero on success, non-zero otherwise. + */ + virtual int disconnect (const std::string& src, const std::string& dst) = 0; + + + /** Ensure that data written to the port referenced by @param portwill be + * readable from the port named by @param dst. Return zero on success, + * non-zero otherwise. + */ + virtual int connect (PortHandle src, const std::string& dst) = 0; + /** Remove any existing connection between the port referenced by @param src and + * the port named @param dst. Return zero on success, non-zero otherwise. + */ + virtual int disconnect (PortHandle src, const std::string& dst) = 0; + + /** Remove all connections between the port referred to by @param port and + * any other ports. Return zero on success, non-zero otherwise. + */ + virtual int disconnect_all (PortHandle port) = 0; + + /** Return true if the port referred to by @param port has any connections + * to other ports. Return false otherwise. + */ + virtual bool connected (PortHandle port, bool process_callback_safe = true) = 0; + /** Return true if the port referred to by @param port is connected to + * the port named by @param name. Return false otherwise. + */ + virtual bool connected_to (PortHandle, const std::string& name, bool process_callback_safe = true) = 0; + + /** Return true if the port referred to by @param port has any connections + * to ports marked with the PortFlag IsPhysical. Return false otherwise. + */ + virtual bool physically_connected (PortHandle port, bool process_callback_safe = true) = 0; + + /** Place the names of all ports connected to the port named by @param + * ports into @param names, and return the number of connections. + */ + virtual int get_connections (PortHandle port, std::vector<std::string>& names, bool process_callback_safe = true) = 0; + + /* MIDI */ + + /** Retrieve a MIDI event from the data at @param port_buffer. The event + number to be retrieved is given by @param event_index (a value of zero + indicates that the first event in the port_buffer should be retrieved). + * + * The data associated with the event will be copied into the buffer at + * @param buf and the number of bytes written will be stored in @param + * size. The timestamp of the event (which is always relative to the start + * of the current process cycle, in samples) will be stored in @param + * timestamp + */ + virtual int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t** buf, void* port_buffer, uint32_t event_index) = 0; + + /** Place a MIDI event consisting of @param size bytes copied from the data + * at @param buf into the port buffer referred to by @param + * port_buffer. The MIDI event will be marked with a time given by @param + * timestamp. Return zero on success, non-zero otherwise. + * + * Events must be added monotonically to a port buffer. An attempt to + * add a non-monotonic event (e.g. out-of-order) will cause this method + * to return a failure status. + */ + virtual int midi_event_put (void* port_buffer, pframes_t timestamp, const uint8_t* buffer, size_t size) = 0; + + /** Return the number of MIDI events in the data at @param port_buffer + */ + virtual uint32_t get_midi_event_count (void* port_buffer) = 0; + + /** Clear the buffer at @param port_buffer of all MIDI events. + * + * After a call to this method, an immediate, subsequent call to + * get_midi_event_count() with the same @param port_buffer argument must + * return zero. + */ + virtual void midi_clear (void* port_buffer) = 0; + + /* Monitoring */ + + /** Return true if the implementation can offer input monitoring. + * + * Input monitoring involves the (selective) routing of incoming data + * to an outgoing data stream, without the data being passed to the CPU. + * + * Only certain audio hardware can provide this, and only certain audio + * APIs can offer it. + */ + virtual bool can_monitor_input() const = 0; + /** Increment or decrement the number of requests to monitor the input + * of the hardware channel represented by the port referred to by @param + * port. + * + * If the number of requests rises above zero, input monitoring will + * be enabled (if can_monitor_input() returns true for the implementation). + * + * If the number of requests falls to zero, input monitoring will be + * disabled (if can_monitor_input() returns true for the implementation) + */ + virtual int request_input_monitoring (PortHandle port, bool yn) = 0; + /* Force input monitoring of the hardware channel represented by the port + * referred to by @param port to be on or off, depending on the true/false + * status of @param yn. The request count is ignored when using this + * method, so if this is called with yn set to false, input monitoring will + * be disabled regardless of the number of requests to enable it. + */ + virtual int ensure_input_monitoring (PortHandle port, bool yn) = 0; + /** Return true if input monitoring is enabled for the hardware channel + * represented by the port referred to by @param port. Return false + * otherwise. + */ + virtual bool monitoring_input (PortHandle port) = 0; + + /* Latency management + */ + + /** Set the latency range for the port referred to by @param port to @param + * r. The playback range will be set if @param for_playback is true, + * otherwise the capture range will be set. + */ + virtual void set_latency_range (PortHandle port, bool for_playback, LatencyRange r) = 0; + /** Return the latency range for the port referred to by @param port. + * The playback range will be returned if @param for_playback is true, + * otherwise the capture range will be returned. + */ + virtual LatencyRange get_latency_range (PortHandle port, bool for_playback) = 0; + + /* Discovering physical ports */ + + /** Return true if the port referred to by @param port has the IsPhysical + * flag set. Return false otherwise. + */ + virtual bool port_is_physical (PortHandle port) const = 0; + + /** Store into @param names the names of all ports with the IsOutput and + * IsPhysical flag set, that handle data of type @param type. + * + * This can be used to discover outputs associated with hardware devices. + */ + virtual void get_physical_outputs (DataType type, std::vector<std::string>& names) = 0; + /** Store into @param names the names of all ports with the IsInput and + * IsPhysical flags set, that handle data of type @param type. + * + * This can be used to discover inputs associated with hardware devices. + */ + virtual void get_physical_inputs (DataType type, std::vector<std::string>& names) = 0; + /** Return the total count (possibly mixed between different data types) + of the number of ports with the IsPhysical and IsOutput flags set. + */ + virtual ChanCount n_physical_outputs () const = 0; + /** Return the total count (possibly mixed between different data types) + of the number of ports with the IsPhysical and IsInput flags set. + */ + virtual ChanCount n_physical_inputs () const = 0; + + /** Return the address of the memory area where data for the port can be + * written (if the port has the PortFlag IsOutput set) or read (if the port + * has the PortFlag IsInput set). + * + * The return value is untyped because buffers containing different data + * depending on the port type. + */ + virtual void* get_buffer (PortHandle, pframes_t) = 0; + + /* MIDI ports (the ones in libmidi++) need this to be able to correctly + * schedule MIDI events within their buffers. It is a bit odd that we + * expose this here, because it is also exposed by AudioBackend, but they + * only have access to a PortEngine object, not an AudioBackend. + * + * Return the time according to the sample clock in use when the current + * buffer process cycle began. + * + * XXX to be removed after some more design cleanup. + */ + virtual pframes_t sample_time_at_cycle_start () = 0; + + protected: + PortManager& manager; +}; + +} + +#endif /* __libardour_port_engine_h__ */ |