XdkWrl: AudioClip Class Reference

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# AudioClip Class Reference
[Standard Node Types]

`#include <audioclip.h>`

Inherits Node.

List of all members.

## Public Member Functions
| AudioClip (const char *name="")
virtual | ~AudioClip ()
virtual unsigned int | nbFields () const
virtual FieldHandle | field (const std::string &n)
virtual FieldHandle | field (unsigned int i)
virtual bool | isSetToDefaultValue (unsigned int i) const
virtual unsigned int | nbEventsIn () const
virtual EventInHandle | eventIn (const std::string &n)
virtual EventInHandle | eventIn (unsigned int i)
virtual unsigned int | nbEventsOut () const
virtual EventOutHandle | eventOut (const std::string &n)
virtual EventOutHandle | eventOut (unsigned int i)
const char * | typeName () const
virtual Node * | duplicate () const
virtual Node * | duplicate (std::map< const Node *, Node * > &) const
## Public Attributes
Exposed Fields
A field that is capable of receiving events via an eventIn to change its value(s), and generating events via an eventOut when its value(s) change.
SFString | description
SFBool | loop
SFFloat | pitch
SFTime | startTime
SFTime | stopTime
MFString | url
Events In
EventIn< SFString > | set_description
EventIn< SFBool > | set_loop
EventIn< SFFloat > | set_pitch
EventIn< SFTime > | set_startTime
EventIn< SFTime > | set_stopTime
EventIn< MFString > | set_url
Events Out
EventOut< SFTime > | duration_changed
EventOut< SFBool > | isActive
EventOut< SFString > | description_changed
EventOut< SFBool > | loop_changed
EventOut< SFFloat > | pitch_changed
EventOut< SFTime > | startTime_changed
EventOut< SFTime > | stopTime_changed
EventOut< MFString > | url_changed

## Detailed Description

Here is the documentation for this node type, from the ISO standard.

## 6.4 AudioClip

An AudioClip node specifies audio data that can be referenced by Sound nodes.

The description field specifies a textual description of the audio source. A browser is not required to display the description field but may choose to do so in addition to playing the sound.

The url field specifies the URL from which the sound is loaded. Browsers shall support at least the wavefile format in uncompressed PCM format (see E.[WAV]). It is recommended that browsers also support the MIDI file type 1 sound format (see 2.[MIDI]); MIDI files are presumed to use the General MIDI patch set. Subclause 4.5, VRML and the World Wide Web, contains details on the url field. The results are undefined when no URLs refer to supported data types

The loop, startTime, and stopTime exposedFields and the isActive eventOut, and their effects on the AudioClip node, are discussed in detail in 4.6.9, Time-dependent nodes. The "cycle" of an AudioClip is the length of time in seconds for one playing of the audio at the specified pitch.

The pitch field specifies a multiplier for the rate at which sampled sound is played. Values for the pitch field shall be greater than zero. Changing the pitch field affects both the pitch and playback speed of a sound. A set_pitch event to an active AudioClip is ignored and no pitch_changed eventOut is generated. If pitch is set to 2.0, the sound shall be played one octave higher than normal and played twice as fast. For a sampled sound, the pitch field alters the sampling rate at which the sound is played. The proper implementation of pitch control for MIDI (or other note sequence sound clips) is to multiply the tempo of the playback by the pitch value and adjust the MIDI Coarse Tune and Fine Tune controls to achieve the proper pitch change.

A duration_changed event is sent whenever there is a new value for the "normal" duration of the clip. Typically, this will only occur when the current url in use changes and the sound data has been loaded, indicating that the clip is playing a different sound source. The duration is the length of time in seconds for one cycle of the audio for a pitch set to 1.0. Changing the pitch field will not trigger a duration_changed event. A duration value of "-1" implies that the sound data has not yet loaded or the value is unavailable for some reason. A duration_changed event shall be generated if the AudioClip node is loaded when the VRML file is read or the AudioClip node is added to the scene graph.

The isActive eventOut may be used by other nodes to determine if the clip is currently active. If an AudioClip is active, it shall be playing the sound corresponding to the sound time (i.e., in the sound's local time system with sample 0 at time 0):

        t = (now - startTime) modulo (duration / pitch)

## Constructor & Destructor Documentation

AudioClip | ( | const char * | name = `""` | ) |

Construct a node with all its fields set to default value, which is equivalent to the code below:

      description = string("");
      loop = false;
      pitch = 1.0f;
      startTime.setNbSeconds(0);
      stopTime.setNbSeconds(0);

~AudioClip | ( |  | ) | `[virtual]`

Virtual destructor, does nothing

## Member Function Documentation

unsigned int nbFields | ( |  | ) | const`[inline, virtual]`

Returns the number of fields (exposed or not) for this node type.

Implements Node.

wrl::Node::FieldHandle field | ( | const std::string & | n | ) | `[virtual]`

Return a handle on the field named `n` of the node or a "unknown" typed handle if there is no such field. Valid names are:

- description
- loop
- pitch
- startTime
- stopTime
- url

Implements Node.

wrl::Node::FieldHandle field | ( | unsigned int | n | ) | `[virtual]`

Return a handle on the `i` th field of the node or a "unknown" typed handle if there is no such node. Here is how `i` is related to fields:

- 0 : description
- 1 : loop
- 2 : pitch
- 3 : startTime
- 4 : stopTime
- 5 : url This function is useful, with nbFields() if you want to traverse all fields of a Node.

Implements Node.

bool isSetToDefaultValue | ( | unsigned int | i | ) | const`[virtual]`

Implements Node.

unsigned int nbEventsIn | ( |  | ) | const`[inline, virtual]`

Returns the number of events in for this node type.

Implements Node.

wrl::Node::EventInHandle eventIn | ( | const std::string & | n | ) | `[virtual]`

Return a handle on the event in named `n` of the node or a "unknown" typed handle if there is no such event. Valid names are:

- set_description
- set_loop
- set_pitch
- set_startTime
- set_stopTime
- set_url

Implements Node.

wrl::Node::EventInHandle eventIn | ( | unsigned int | n | ) | `[virtual]`

Return a handle on the `i` th event in of the node or a "unknown" typed handle if there is no such node. emarks This class has no eventIn. This function is useful, with nbEventsIn() if you want to traverse all events in of a Node.

Implements Node.

unsigned int nbEventsOut | ( |  | ) | const`[inline, virtual]`

Returns the number of events out for this node type.

Implements Node.

wrl::Node::EventOutHandle eventOut | ( | const std::string & | n | ) | `[virtual]`

Return a handle on the event out named `n` of the node or a "unknown" typed handle if there is no such event. Valid names are:

- duration_changed
- isActive
- description_changed
- loop_changed
- pitch_changed
- startTime_changed
- stopTime_changed
- url_changed

Implements Node.

wrl::Node::EventOutHandle eventOut | ( | unsigned int | n | ) | `[virtual]`

Return a handle on the `i` th event out of the node or a "unknown" typed handle if there is no such node. Here is how `i` is related to fields:

- 0 : duration_changed
- 1 : isActive
- 2 : description_changed
- 3 : loop_changed
- 4 : pitch_changed
- 5 : startTime_changed
- 6 : stopTime_changed
- 7 : url_changed This function is useful, with nbEventsOut() if you want to traverse all events in of a Node.

Implements Node.

const char * typeName | ( |  | ) | const`[inline, virtual]`

Returns `"AudioClip"`. Useful for printing.

Implements Node.

wrl::Node * duplicate | ( |  | ) | const`[virtual]`

Returns a deep copy of this node, that is a fully independant node with all children (if any) also copied. This is mainly useful for instanciating protos.

Implements Node.

virtual Node* duplicate | ( | std::map< const Node *, Node * > & |  | ) | const`[virtual]`

Implements Node.

## Member Data Documentation

SFString description

See Detailed Description for meaning of this field. Default value is set to

           description = string("");

SFBool loop

See Detailed Description for meaning of this field. Default value is set to

           loop = false;

SFFloat pitch

See Detailed Description for meaning of this field. Default value is set to

           pitch = 1.0f;

SFTime startTime

See Detailed Description for meaning of this field. Default value is set to

           startTime.setNbSeconds(0);

SFTime stopTime

See Detailed Description for meaning of this field. Default value is set to

           stopTime.setNbSeconds(0);

MFString url

See Detailed Description for meaning of this field. Default value is set to MFString default value

EventIn<SFString> set_description

Set event associated to exposedField description

EventIn<SFBool> set_loop

Set event associated to exposedField loop

EventIn<SFFloat> set_pitch

Set event associated to exposedField pitch

EventIn<SFTime> set_startTime

Set event associated to exposedField startTime

EventIn<SFTime> set_stopTime

Set event associated to exposedField stopTime

EventIn<MFString> set_url

Set event associated to exposedField url

EventOut<SFTime> duration_changed

See Detailed Description for meaning of this event.

EventOut<SFBool> isActive

See Detailed Description for meaning of this event.

EventOut<SFString> description_changed

Changed event associated to exposedField description

EventOut<SFBool> loop_changed

Changed event associated to exposedField loop

EventOut<SFFloat> pitch_changed

Changed event associated to exposedField pitch

EventOut<SFTime> startTime_changed

Changed event associated to exposedField startTime

EventOut<SFTime> stopTime_changed

Changed event associated to exposedField stopTime

EventOut<MFString> url_changed

Changed event associated to exposedField url

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