less complicated RotationAccumulator

libraries/animation/src/RotationAccumulator.cpp

@@ -11,19 +11,18 @@
 
 #include <glm/gtx/quaternion.hpp>
 
-glm::quat RotationAccumulator::getAverage() {
-    glm::quat average;
-    uint32_t numRotations = _rotations.size();
-    if (numRotations > 0) {
-        average = _rotations[0];
-        for (uint32_t i = 1; i < numRotations; ++i) {
-            glm::quat rotation = _rotations[i];
-            if (glm::dot(average, rotation) < 0.0f) {
+void RotationAccumulator::add(glm::quat rotation) {
+    if (_numRotations == 0) {
+        _rotationSum = rotation;
+    } else {
+        if (glm::dot(_rotationSum, rotation) < 0.0f) {
             rotation = -rotation;
         }
-            average += rotation;
+        _rotationSum += rotation;
     }
-        average = glm::normalize(average);
+    ++_numRotations;
 }
-    return average;
+
+glm::quat RotationAccumulator::getAverage() {
+    return (_numRotations > 0) ?  glm::normalize(_rotationSum) : glm::quat();
 }

libraries/animation/src/RotationAccumulator.h

@@ -10,25 +10,21 @@
 #ifndef hifi_RotationAccumulator_h
 #define hifi_RotationAccumulator_h
 
-#include <vector>
-
 #include <glm/gtc/quaternion.hpp>
-#include <glm/gtx/quaternion.hpp>
 
 class RotationAccumulator {
 public:
-    RotationAccumulator() {}
+    int size() const { return _numRotations; }
 
-    uint32_t size() const { return _rotations.size(); }
-
-    void add(const glm::quat& rotation) { _rotations.push_back(rotation); }
+    void add(glm::quat rotation);
 
     glm::quat getAverage();
 
-    void clear() { _rotations.clear(); }
+    void clear() { _numRotations = 0; }
 
 private:
-    std::vector<glm::quat> _rotations;
+    glm::quat _rotationSum;
+    int _numRotations = 0;
 };
 
 #endif // hifi_RotationAccumulator_h