time-box Picks and solve in round-robin sequence

interface/src/raypick/PickScriptingInterface.cpp

@@ -175,3 +175,11 @@ void PickScriptingInterface::registerMetaTypes(QScriptEngine* engine) {
 
     qScriptRegisterMetaType(engine, pickTypesToScriptValue, pickTypesFromScriptValue);
 }
+
+unsigned int PickScriptingInterface::getPerFrameTimeBudget() const {
+    return DependencyManager::get<PickManager>()->getPerFrameTimeBudget();
+}
+
+void PickScriptingInterface::setPerFrameTimeBudget(unsigned int numUsecs) {
+    DependencyManager::get<PickManager>()->setPerFrameTimeBudget(numUsecs);
+}

interface/src/raypick/PickScriptingInterface.h

@@ -185,6 +185,14 @@ public:
      */
     Q_INVOKABLE bool isMouse(unsigned int uid);
 
+    Q_PROPERTY(unsigned int perFrameTimeBudget READ getPerFrameTimeBudget WRITE setPerFrameTimeBudget)
+    /**jsdoc
+     * The max number of usec to spend per frame updating Pick results.
+     * @typedef {number} Picks.perFrameTimeBudget
+     */
+    unsigned int getPerFrameTimeBudget() const;
+    void setPerFrameTimeBudget(unsigned int numUsecs);
+
 public slots:
     static constexpr unsigned int PICK_NOTHING() { return 0; }
     static constexpr unsigned int PICK_ENTITIES() { return PickFilter::getBitMask(PickFilter::FlagBit::PICK_ENTITIES); }

libraries/pointers/src/PickCacheOptimizer.h

@@ -37,7 +37,7 @@ template<typename T>
 class PickCacheOptimizer {
 
 public:
-    void update(std::unordered_map<unsigned int, std::shared_ptr<PickQuery>>& picks, bool shouldPickHUD);
+    void update(std::unordered_map<uint32_t, std::shared_ptr<PickQuery>>& picks, uint32_t& nextToUpdate, uint64_t expiry, bool shouldPickHUD);
 
 protected:
     typedef std::unordered_map<T, std::unordered_map<PickCacheKey, PickResultPointer>> PickCache;
@@ -67,19 +67,26 @@ void PickCacheOptimizer<T>::cacheResult(const bool intersects, const PickResultP
 }
 
 template<typename T>
-void PickCacheOptimizer<T>::update(std::unordered_map<unsigned int, std::shared_ptr<PickQuery>>& picks, bool shouldPickHUD) {
+void PickCacheOptimizer<T>::update(std::unordered_map<uint32_t, std::shared_ptr<PickQuery>>& picks,
+        uint32_t& nextToUpdate, uint64_t expiry, bool shouldPickHUD) {
     PickCache results;
-    for (const auto& pickPair : picks) {
-        std::shared_ptr<Pick<T>> pick = std::static_pointer_cast<Pick<T>>(pickPair.second);
-
+    const uint32_t INVALID_PICK_ID = 0;
+    std::unordered_map<uint32_t, std::shared_ptr<PickQuery>>::iterator itr = picks.begin();
+    if (nextToUpdate != INVALID_PICK_ID) {
+        itr = picks.find(nextToUpdate);
+        if (itr == picks.end()) {
+            itr = picks.begin();
+        }
+    }
+    uint32_t numUpdates = 0;
+    while(numUpdates < picks.size()) {
+        std::shared_ptr<Pick<T>> pick = std::static_pointer_cast<Pick<T>>(itr->second);
         T mathematicalPick = pick->getMathematicalPick();
         PickResultPointer res = pick->getDefaultResult(mathematicalPick.toVariantMap());
 
         if (!pick->isEnabled() || pick->getFilter().doesPickNothing() || pick->getMaxDistance() < 0.0f || !mathematicalPick) {
             pick->setPickResult(res);
-            continue;
-        }
-
+        } else {
             if (pick->getFilter().doesPickEntities()) {
                 PickCacheKey entityKey = { pick->getFilter().getEntityFlags(), pick->getIncludeItems(), pick->getIgnoreItems() };
                 if (!checkAndCompareCachedResults(mathematicalPick, results, res, entityKey)) {
@@ -127,6 +134,18 @@ void PickCacheOptimizer<T>::update(std::unordered_map<unsigned int, std::shared_
                 pick->setPickResult(pick->getDefaultResult(mathematicalPick.toVariantMap()));
             }
         }
+
+        ++itr;
+        if (itr == picks.end()) {
+            itr = picks.begin();
+        }
+        nextToUpdate = itr->first;
+        ++numUpdates;
+        uint64_t now = usecTimestampNow();
+        if (usecTimestampNow() > expiry) {
+            break;
+        }
+    }
 }
 
 #endif // hifi_PickCacheOptimizer_h

libraries/pointers/src/PickManager.cpp

@@ -89,14 +89,17 @@ void PickManager::setIncludeItems(unsigned int uid, const QVector<QUuid>& includ
 }
 
 void PickManager::update() {
+    uint64_t expiry = usecTimestampNow() + _perFrameTimeBudget;
     std::unordered_map<PickQuery::PickType, std::unordered_map<unsigned int, std::shared_ptr<PickQuery>>> cachedPicks;
     withReadLock([&] {
         cachedPicks = _picks;
     });
 
     bool shouldPickHUD = _shouldPickHUDOperator();
-    _rayPickCacheOptimizer.update(cachedPicks[PickQuery::Ray], shouldPickHUD);
-    _stylusPickCacheOptimizer.update(cachedPicks[PickQuery::Stylus], false);
+    // we pass the same expiry to both updates
+    // even when the rayPicks consume all the budget at least one stylus will be updated
+    _rayPickCacheOptimizer.update(cachedPicks[PickQuery::Ray], _nextPickToUpdate[PickQuery::Ray], expiry, shouldPickHUD);
+    _stylusPickCacheOptimizer.update(cachedPicks[PickQuery::Stylus], _nextPickToUpdate[PickQuery::Stylus], expiry, false);
 }
 
 bool PickManager::isLeftHand(unsigned int uid) {

libraries/pointers/src/PickManager.h

@@ -14,6 +14,8 @@
 #include "Pick.h"
 #include "PickCacheOptimizer.h"
 
+#include <NumericalConstants.h>
+
 class PickManager : public Dependency, protected ReadWriteLockable {
     SINGLETON_DEPENDENCY
 
@@ -48,17 +50,24 @@ public:
 
     static const unsigned int INVALID_PICK_ID { 0 };
 
+    unsigned int getPerFrameTimeBudget() const { return _perFrameTimeBudget; }
+    void setPerFrameTimeBudget(unsigned int numUsecs) { _perFrameTimeBudget = numUsecs; }
+
 protected:
     std::function<bool()> _shouldPickHUDOperator;
     std::function<glm::vec2(const glm::vec3&)> _calculatePos2DFromHUDOperator;
 
     std::shared_ptr<PickQuery> findPick(unsigned int uid) const;
     std::unordered_map<PickQuery::PickType, std::unordered_map<unsigned int, std::shared_ptr<PickQuery>>> _picks;
+    unsigned int _nextPickToUpdate[PickQuery::NUM_PICK_TYPES] { 0, 0 };
     std::unordered_map<unsigned int, PickQuery::PickType> _typeMap;
     unsigned int _nextPickID { INVALID_PICK_ID + 1 };
 
     PickCacheOptimizer<PickRay> _rayPickCacheOptimizer;
     PickCacheOptimizer<StylusTip> _stylusPickCacheOptimizer;
+
+    static const unsigned int DEFAULT_PER_FRAME_TIME_BUDGET = 2 * USECS_PER_MSEC;
+    unsigned int _perFrameTimeBudget { DEFAULT_PER_FRAME_TIME_BUDGET };
 };
 
 #endif // hifi_PickManager_h