library: add the TransformTrackBuilder class

WesLibrary/src/main/java/jme3utilities/wes/TransformTrackBuilder.java

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+/*
+ Copyright (c) 2023, Stephen Gold
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * Neither the name of the copyright holder nor the names of its contributors
+ may be used to endorse or promote products derived from this software without
+ specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package jme3utilities.wes;
+
+import com.jme3.anim.TransformTrack;
+import com.jme3.anim.util.HasLocalTransform;
+import com.jme3.math.Quaternion;
+import com.jme3.math.Vector3f;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import java.util.logging.Logger;
+import jme3utilities.Validate;
+import jme3utilities.math.MyArray;
+import jme3utilities.math.MyQuaternion;
+
+/**
+ * Gather the data needed to construct a JMonkeyEngine TransformTrack.
+ *
+ * @author Stephen Gold [email protected]
+ */
+public class TransformTrackBuilder {
+    // *************************************************************************
+    // constants and loggers
+
+    /**
+     * message logger for this class
+     */
+    final private static Logger logger
+            = Logger.getLogger(TransformTrackBuilder.class.getName());
+    // *************************************************************************
+    // fields
+
+    /**
+     * expected duration of the track (in seconds)
+     */
+    final private float duration;
+    /**
+     * target of the resulting animation track
+     */
+    final private HasLocalTransform target;
+    /**
+     * maps animation times to rotation vectors
+     */
+    final private Map<Float, Quaternion> rotationMap = new TreeMap<>();
+    /**
+     * maps animation times to scale vectors
+     */
+    final private Map<Float, Vector3f> scaleMap = new TreeMap<>();
+    /**
+     * maps animation times to translation vectors
+     */
+    final private Map<Float, Vector3f> translationMap = new TreeMap<>();
+    /**
+     * collects the animation times of all keyframes (in seconds)
+     */
+    final private Set<Float> timeSet = new TreeSet<>();
+    /**
+     * interpolation algorithm for rotations
+     */
+    private TweenRotations tweenRotations = TweenRotations.LoopSpline;
+    /**
+     * interpolation algorithm for scale vectors
+     */
+    private TweenVectors tweenScales = TweenVectors.LoopFdcSpline;
+    /**
+     * interpolation algorithm for translation vectors
+     */
+    private TweenVectors tweenTranslations = TweenVectors.LoopFdcSpline;
+    // *************************************************************************
+    // constructors
+
+    /**
+     * Instantiate a builder for the specified target.
+     *
+     * @param target the animation target, typically an animation joint or a
+     * Spatial (not null)
+     * @param duration the expected duration of the animation clip (in seconds,
+     * &ge;0)
+     */
+    public TransformTrackBuilder(HasLocalTransform target, float duration) {
+        Validate.nonNull(target, "target");
+        Validate.nonNegative(duration, "duration");
+
+        this.target = target;
+        this.duration = duration;
+    }
+    // *************************************************************************
+    // new methods exposed
+
+    /**
+     * Add a rotation keyframe.
+     *
+     * @param time the animation time (in seconds, &ge;0, &le;duration)
+     * @param rotation the desired rotation at that time (not null, unaffected)
+     */
+    public void addRotation(float time, Quaternion rotation) {
+        Validate.inRange(time, "time", 0f, duration);
+        MyQuaternion.validateUnit(rotation, "rotation", 0.0005f);
+
+        Quaternion cloneRotation = rotation.clone();
+        rotationMap.put(time, cloneRotation);
+        timeSet.add(time);
+    }
+
+    /**
+     * Add a scaling keyframe.
+     *
+     * @param time the animation time (in seconds, &ge;0, &le;duration)
+     * @param scale the desired scale factors at that time (not null,
+     * unaffected)
+     */
+    public void addScale(float time, Vector3f scale) {
+        Validate.inRange(time, "time", 0f, duration);
+
+        Vector3f cloneScale = scale.clone();
+        scaleMap.put(time, cloneScale);
+        timeSet.add(time);
+    }
+
+    /**
+     * Add a translation keyframe.
+     *
+     * @param time the animation time (in seconds, &ge;0, &le;duration)
+     * @param translation the desired translation at that time (not null,
+     * unaffected)
+     */
+    public void addTranslation(float time, Vector3f translation) {
+        Validate.inRange(time, "time", 0f, duration);
+
+        Vector3f cloneTranslation = translation.clone();
+        translationMap.put(time, cloneTranslation);
+        timeSet.add(time);
+    }
+
+    /**
+     * Create a TransformTrack.
+     *
+     * @return a new instance (not null)
+     */
+    public TransformTrack build() {
+        // Convert keyframe data to curves for efficient interpolation:
+        VectorCurve scaleCurve = toVectorCurve(scaleMap);
+        RotationCurve rotationCurve = toRotationCurve(rotationMap);
+        VectorCurve translationCurve = toVectorCurve(translationMap);
+
+        // Generate the merged array of keyframe times:
+        float[] times = toFloatArray(timeSet);
+        int numFrames = times.length;
+
+        // Allocate arrays for (possibly interpolated) track data:
+        Vector3f[] translations = new Vector3f[numFrames];
+        Quaternion[] rotations = new Quaternion[numFrames];
+        Vector3f[] scales = new Vector3f[numFrames];
+
+        for (int frameIndex = 0; frameIndex < numFrames; ++frameIndex) {
+            float time = times[frameIndex];
+
+            Vector3f translation = translationMap.get(time);
+            if (translation == null) {
+                translation = tweenTranslations.interpolate(
+                        time, translationCurve, null);
+            }
+            translations[frameIndex] = translation;
+
+            Quaternion rotation = rotationMap.get(time);
+            if (rotation == null) {
+                rotation
+                        = tweenRotations.interpolate(time, rotationCurve, null);
+            }
+            rotations[frameIndex] = rotation;
+
+            Vector3f scale = scaleMap.get(time);
+            if (scale == null) {
+                scale = tweenScales.interpolate(time, scaleCurve, null);
+            }
+            scales[frameIndex] = scale;
+        }
+
+        TransformTrack result = new TransformTrack(
+                target, times, translations, rotations, scales);
+
+        return result;
+    }
+
+    /**
+     * Alter the technique for rotations.
+     *
+     * @param newTechnique (not null, default=LoopSpline)
+     */
+    public void setTweenRotations(TweenRotations newTechnique) {
+        Validate.nonNull(newTechnique, "new technique");
+        this.tweenRotations = newTechnique;
+    }
+
+    /**
+     * Alter the technique for scales.
+     *
+     * @param newTechnique (not null, default=LoopFdcSpline)
+     */
+    public void setTweenScales(TweenVectors newTechnique) {
+        Validate.nonNull(newTechnique, "new technique");
+        this.tweenScales = newTechnique;
+    }
+
+    /**
+     * Alter the technique for translations.
+     *
+     * @param newTechnique (not null, default=LoopFdcSpline)
+     */
+    public void setTweenTranslations(TweenVectors newTechnique) {
+        Validate.nonNull(newTechnique, "new technique");
+        this.tweenTranslations = newTechnique;
+    }
+    // *************************************************************************
+    // private methods
+
+    /**
+     * Convert the specified set of times to an array and verify that it is in
+     * ascending order.
+     *
+     * @param timeSet the input set (not null, unaffected)
+     * @return a new array, sorted in ascending order
+     */
+    private static float[] toFloatArray(Set<Float> timeSet) {
+        int numFrames = timeSet.size();
+        float[] result = new float[numFrames];
+
+        int frameIndex = 0;
+        for (float time : timeSet) {
+            result[frameIndex] = time;
+            ++frameIndex;
+        }
+
+        assert MyArray.isSorted(result);
+        return result;
+    }
+
+    /**
+     * Convert the specified Map into a RotationCurve for interpolation.
+     *
+     * @param map the input map (not null, unaffected)
+     * @return a new instance (not null)
+     */
+    private RotationCurve toRotationCurve(Map<Float, Quaternion> map) {
+        float[] times = toFloatArray(map.keySet());
+
+        int numFrames = times.length;
+        Quaternion[] array = new Quaternion[numFrames];
+
+        for (int frameIndex = 0; frameIndex < numFrames; ++frameIndex) {
+            float time = times[frameIndex];
+            Quaternion rotation = map.get(time);
+            array[frameIndex] = rotation.clone();
+        }
+        RotationCurve result = new RotationCurve(times, duration, array);
+
+        return result;
+    }
+
+    /**
+     * Convert the specified Map into a VectorCurve for interpolation.
+     *
+     * @param map the input map (not null, unaffected)
+     * @return a new instance (not null)
+     */
+    private VectorCurve toVectorCurve(Map<Float, Vector3f> map) {
+        float[] times = toFloatArray(map.keySet());
+
+        int numFrames = times.length;
+        Vector3f[] array = new Vector3f[numFrames];
+
+        for (int frameIndex = 0; frameIndex < numFrames; ++frameIndex) {
+            float time = times[frameIndex];
+            Vector3f vector = map.get(time);
+            array[frameIndex] = vector.clone();
+        }
+        VectorCurve result = new VectorCurve(times, duration, array);
+
+        return result;
+    }
+}