Merge pull request #665 from rtoy/rtoy-652-specify-set-target-behavior

Specify behavior of events following SetTarget events.

index.html

@@ -3036,6 +3036,19 @@ <h2 id="AudioParam">
               "#widl-AudioContext-currentTime">currentTime</a> at the time
               <code>linearRampToValueAtTime</code> is called.
             </p>
+            <p>
+              If the preceding event is a <em>SetTarget</em> event, \(T_0\) and
+              \(V_0\) are chosen from the current time and value of
+              <em>SetTarget</em> automation. That is, if the <em>SetTarget</em>
+              event has not started, \(T_0\) is the start time of the event,
+              and \(V_0\) is the value just before the <em>SetTarget</em> event
+              starts. In this case, the <em>LinearRampToValue</em> event
+              effectively replaces the <em>SetTarget</em> event. If the
+              <em>SetTarget</em> event has already started, \(T_0\) is the
+              current context time, and \(V_0\) is the current
+              <em>SetTarget</em> automation value at time \(T_0\). In both
+              cases, the automation curve is continuous.
+            </p>
           </dd>
           <dt>
             AudioParam exponentialRampToValueAtTime(float value, double
@@ -3084,6 +3097,19 @@ <h2 id="AudioParam">
               "#widl-AudioContext-currentTime">currentTime</a> at the time
               <code>exponentialRampToValueAtTime</code> is called.
             </p>
+            <p>
+              If the preceding event is a <em>SetTarget</em> event, \(T_0\) and
+              \(V_0\) are chosen from the current time and value of
+              <em>SetTarget</em> automation. That is, if the <em>SetTarget</em>
+              event has not started, \(T_0\) is the start time of the event,
+              and \(V_0\) is the value just before the <em>SetTarget</em> event
+              starts. In this case, the <em>ExponentialRampToValue</em> event
+              effectively replaces the <em>SetTarget</em> event. If the
+              <em>SetTarget</em> event has already started, \(T_0\) is the
+              current context time, and \(V_0\) is the current
+              <em>SetTarget</em> automation value at time \(T_0\). In both
+              cases, the automation curve is continuous.
+            </p>
             <dl class="parameters">
               <dt>
                 float value
@@ -3157,10 +3183,8 @@ <h2 id="AudioParam">
               </dd>
             </dl>
             <p>
-              During the time interval: \(T_0 \leq t &lt; T_1\), where \(T_0\)
-              is the <code>startTime</code> parameter and \(T_1\) represents
-              the time of the event following this event (or \(\infty\) if
-              there are no following events):
+              During the time interval: \(T_0 \leq t\), where \(T_0\) is the
+              <code>startTime</code> parameter:
             </p>
             <pre class="nohighlight">
               $$
@@ -3174,6 +3198,17 @@ <h2 id="AudioParam">
               \(V_1\) is equal to the <code>target</code> parameter, and
               \(\tau\) is the <code>timeConstant</code> parameter.
             </p>
+            <p>
+              If a <em>LinearRampToValue</em> or
+              <em>ExponentialRampToValue</em> event follows this event, the
+              behavior is described in <code><a href=
+              "#widl-AudioParam-linearRampToValueAtTime-AudioParam-float-value-double-endTime">
+              linearRampToValueAtTime</a></code> or <code><a href=
+              "#widl-AudioParam-exponentialRampToValueAtTime-AudioParam-float-value-double-endTime">
+              exponentialRampToValueAtTime</a></code>, respectively. For all
+              other events, the <em>SetTarget</em> event ends at the time of
+              the next event.
+            </p>
           </dd>
           <dt>
             AudioParam setValueCurveAtTime(Float32Array values, double