upX
只读特性在
AudioListener
interface is an
AudioParam
representing the x value of the direction vector defining the up direction the listener is pointing in.
注意
: The parameter is
a-rate
when used with a
PannerNode
whose
PannerNode
is set to equalpower, or
k-rate
否则。
var audioCtx = new AudioContext(); var myListener = audioCtx.listener; myListener.upX.value = 0;
AudioParam
. Its default value is 0, and it can range between positive and negative infinity.
In the following example, you can see an example of how the
createPanner()
方法,
AudioListener
and
PannerNode
would be used to control audio spatialisation. Generally you will define the position in 3D space that your audio listener and panner (source) occupy initially, and then update the position of one or both of these as the application is used. You might be moving a character around inside a game world for example, and wanting delivery of audio to change realistically as your character moves closer to or further away from a music player such as a stereo. In the example you can see this being controlled by the functions
moveRight()
,
moveLeft()
, etc., which set new values for the panner position via the
PositionPanner()
函数。
To see a complete implementation, check out our panner-node example ( view the source code ) — this demo transports you to the 2.5D "Room of metal", where you can play a track on a boom box and then walk around the boom box to see how the sound changes!
Note how we have used some feature detection to either give the browser the newer property values (like
AudioListener.forwardX
) for setting position, etc. if it supports those, or older methods (like
AudioListener.setOrientation()
) if it still supports those but not the new properties.
// set up listener and panner position information
var WIDTH = window.innerWidth;
var HEIGHT = window.innerHeight;
var xPos = Math.floor(WIDTH/2);
var yPos = Math.floor(HEIGHT/2);
var zPos = 295;
// define other variables
var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();
var panner = audioCtx.createPanner();
panner.panningModel = 'HRTF';
panner.distanceModel = 'inverse';
panner.refDistance = 1;
panner.maxDistance = 10000;
panner.rolloffFactor = 1;
panner.coneInnerAngle = 360;
panner.coneOuterAngle = 0;
panner.coneOuterGain = 0;
if(panner.orientationX) {
panner.orientationX.setValueAtTime(1, audioCtx.currentTime);
panner.orientationY.setValueAtTime(0, audioCtx.currentTime);
panner.orientationZ.setValueAtTime(0, audioCtx.currentTime);
} else {
panner.setOrientation(1,0,0);
}
var listener = audioCtx.listener;
if(listener.forwardX) {
listener.forwardX.setValueAtTime(0, audioCtx.currentTime);
listener.forwardY.setValueAtTime(0, audioCtx.currentTime);
listener.forwardZ.setValueAtTime(-1, audioCtx.currentTime);
listener.upX.setValueAtTime(0, audioCtx.currentTime);
listener.upY.setValueAtTime(1, audioCtx.currentTime);
listener.upZ.setValueAtTime(0, audioCtx.currentTime);
} else {
listener.setOrientation(0,0,-1,0,1,0);
}
var source;
var play = document.querySelector('.play');
var stop = document.querySelector('.stop');
var boomBox = document.querySelector('.boom-box');
var listenerData = document.querySelector('.listener-data');
var pannerData = document.querySelector('.panner-data');
leftBound = (-xPos) + 50;
rightBound = xPos - 50;
xIterator = WIDTH/150;
// listener will always be in the same place for this demo
if(listener.positionX) {
listener.positionX.setValueAtTime(xPos, audioCtx.currentTime);
listener.positionY.setValueAtTime(yPos, audioCtx.currentTime);
listener.positionZ.setValueAtTime(300, audioCtx.currentTime);
} else {
listener.setPosition(xPos,yPos,300);
}
listenerData.innerHTML = 'Listener data: X ' + xPos + ' Y ' + yPos + ' Z ' + 300;
// panner will move as the boombox graphic moves around on the screen
function positionPanner() {
if(panner.positionX) {
panner.positionX.setValueAtTime(xPos, audioCtx.currentTime);
panner.positionY.setValueAtTime(yPos, audioCtx.currentTime);
panner.positionZ.setValueAtTime(zPos, audioCtx.currentTime);
} else {
panner.setPosition(xPos,yPos,zPos);
}
pannerData.innerHTML = 'Panner data: X ' + xPos + ' Y ' + yPos + ' Z ' + zPos;
}
注意 : In terms of working out what position values to apply to the listener and panner, to make the sound appropriate to what the visuals are doing on screen, there is quite a bit of math involved, but you will soon get used to it with a bit of experimentation.
| 规范 | 状态 | 注释 |
|---|---|---|
|
Web 音频 API
The definition of 'upX' in that specification. |
工作草案 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
upX
|
Chrome 52 | Edge ≤18 | Firefox 不支持 No | IE 不支持 No | Opera 39 | Safari 不支持 No | WebView Android 52 | Chrome Android 52 | Firefox Android 不支持 No | Opera Android 41 | Safari iOS ? | Samsung Internet Android 6.0 |
完整支持
不支持
兼容性未知
见实现注意事项。
AudioListener
AnalyserNode
AudioBuffer
AudioBufferSourceNode
AudioContext
AudioContextOptions
AudioDestinationNode
AudioNode
AudioNodeOptions
AudioParam
AudioProcessingEvent
AudioScheduledSourceNode
AudioWorklet
AudioWorkletGlobalScope
AudioWorkletNode
AudioWorkletProcessor
BaseAudioContext
BiquadFilterNode
ChannelMergerNode
ChannelSplitterNode
ConstantSourceNode
ConvolverNode
DelayNode
DynamicsCompressorNode
GainNode
IIRFilterNode
MediaElementAudioSourceNode
MediaStreamAudioDestinationNode
MediaStreamAudioSourceNode
OfflineAudioCompletionEvent
OfflineAudioContext
OscillatorNode
PannerNode
PeriodicWave
StereoPannerNode
WaveShaperNode