Add optional Gain parameter to Clip

Project.xsd

@@ -517,6 +517,7 @@
     <xs:complexContent>
       <xs:extension base="nameable">
         <xs:sequence>
+          <xs:element name="Gain" type="realParameter" minOccurs="0"/>
           <xs:choice minOccurs="0">
             <xs:element ref="Timeline"/>
             <xs:element ref="Lanes"/>

Reference.html

@@ -2725,6 +2725,25 @@ <h3 id="Clip" class="element-title">
                             Required
                         </th>
                     </tr>
+                    <tr>
+                        <td style="text-align:center;">
+                            &lt;Gain&gt;
+                        </td>
+                        <td>
+                            Gain applied to the audio content of this clip, in addition to the
+                             fade-in/fade-out envelope and independently of the volume of the channel this
+                             clip plays on. Unity gain is the implied default when this element is
+                             omitted.
+                        </td>
+                        <td style="text-align:center;">
+                            <a href="#RealParameter" class="element-link">
+                                &lt;RealParameter&gt;
+                            </a>
+                        </td>
+                        <td style="text-align:center;">
+                            no
+                        </td>
+                    </tr>
                     <tr>
                         <td style="text-align:center;">
                             from Type

src/main/java/com/bitwig/dawproject/timeline/Clip.java

@@ -1,11 +1,13 @@
 package com.bitwig.dawproject.timeline;
 
 import jakarta.xml.bind.annotation.XmlAttribute;
+import jakarta.xml.bind.annotation.XmlElement;
 import jakarta.xml.bind.annotation.XmlElementRef;
 import jakarta.xml.bind.annotation.XmlIDREF;
 import jakarta.xml.bind.annotation.XmlRootElement;
 
 import com.bitwig.dawproject.Nameable;
+import com.bitwig.dawproject.RealParameter;
 
 /**
  * A Clip provides a clipped view on to a Timeline, and is used either on a
@@ -80,6 +82,15 @@ public class Clip extends Nameable {
 	@XmlAttribute(required = false)
 	public Double fadeOutTime;
 
+	/**
+	 * Gain applied to the audio content of this clip, in addition to the
+	 * fade-in/fade-out envelope and independently of the volume of the channel this
+	 * clip plays on. Unity gain is the implied default when this element is
+	 * omitted.
+	 */
+	@XmlElement(name = "Gain", required = false)
+	public RealParameter gain;
+
 	/** Whether this clip should be played back. Default value is true. */
 	@XmlAttribute(required = false)
 	public Boolean enable;

src/test/java/com/bitwig/dawproject/DawProjectTest.java

@@ -99,6 +99,49 @@ public void saveAndLoadDawProject() throws IOException {
 		Assert.assertEquals(project.scenes.size(), loadedProject.scenes.size());
 	}
 
+	/**
+	 * Test storing and loading a clip with gain.
+	 *
+	 * @throws IOException
+	 *             Could not store or load the project
+	 */
+	@Test
+	public void saveAndLoadClipGain() throws IOException {
+		final Project project = createEmptyProject();
+		final Track masterTrack = Utility.createTrack("Master", EnumSet.noneOf(ContentType.class), MixerRole.MASTER, 1,
+				0.5);
+		final var audioTrack = Utility.createTrack("Audio", EnumSet.of(ContentType.AUDIO), MixerRole.REGULAR, 1, 0.5);
+		audioTrack.channel.destination = masterTrack.channel;
+		project.structure.add(masterTrack);
+		project.structure.add(audioTrack);
+
+		project.arrangement = new Arrangement();
+		final var arrangementLanes = new Lanes();
+		arrangementLanes.timeUnit = TimeUnit.BEATS;
+		project.arrangement.lanes = arrangementLanes;
+
+		final var audio = Utility.createAudio("white-glasses.wav", 44100, 2, 3.097);
+		final var audioClip = Utility.createClip(audio, 0, 8);
+		audioClip.contentTimeUnit = TimeUnit.SECONDS;
+		audioClip.gain = Utility.createRealParameter(Unit.LINEAR, 0.5);
+
+		final var clips = Utility.createClips(audioClip);
+		clips.track = audioTrack;
+		arrangementLanes.lanes.add(clips);
+
+		DawProject.validate(project);
+
+		final var file = File.createTempFile("testfile-clip-gain", ".dawproject");
+		DawProject.save(project, new MetaData(), new HashMap<>(), file);
+		final var loadedProject = DawProject.loadProject(file);
+
+		final var loadedLanes = (Lanes) loadedProject.arrangement.lanes;
+		final var loadedClips = (Clips) loadedLanes.lanes.get(0);
+		final var loadedGain = loadedClips.clips.get(0).gain;
+		Assert.assertEquals(Unit.LINEAR, loadedGain.unit);
+		Assert.assertEquals(0.5, loadedGain.value.doubleValue(), 0.0);
+	}
+
 	/**
 	 * Test storing a complex project.
 	 *