From ad25455f868608909f6114ef0776c0cc440d9232 Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <drzej.k@gmail.com>
Date: Wed, 5 Mar 2014 18:06:14 -0800
Subject: [PATCH] Track hysteresis for next model separately, but just in case,
 don't use recursion to fall back on hysteresis value.  Closes #2209.

---
 interface/src/renderer/GeometryCache.cpp | 9 ++++++++-
 interface/src/renderer/Model.cpp         | 5 +++--
 interface/src/renderer/Model.h           | 1 +
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/interface/src/renderer/GeometryCache.cpp b/interface/src/renderer/GeometryCache.cpp
index 5b13e2da42..88d2a8962d 100644
--- a/interface/src/renderer/GeometryCache.cpp
+++ b/interface/src/renderer/GeometryCache.cpp
@@ -343,7 +343,14 @@ QSharedPointer<NetworkGeometry> NetworkGeometry::getLODOrFallback(float distance
         // if we previously selected a different distance, make sure we've moved far enough to justify switching
         const float HYSTERESIS_PROPORTION = 0.1f;
         if (glm::abs(distance - qMax(hysteresis, lodDistance)) / fabsf(hysteresis - lodDistance) < HYSTERESIS_PROPORTION) {
-            return getLODOrFallback(hysteresis, hysteresis);
+            lod = _lodParent;
+            lodDistance = 0.0f;
+            it = _lods.upperBound(hysteresis);
+            if (it != _lods.constBegin()) {
+                it = it - 1;
+                lod = it.value();
+                lodDistance = it.key();
+            }
         }
     }
     if (lod->isLoaded()) {
diff --git a/interface/src/renderer/Model.cpp b/interface/src/renderer/Model.cpp
index 1aab0a4dab..0cff3aaa87 100644
--- a/interface/src/renderer/Model.cpp
+++ b/interface/src/renderer/Model.cpp
@@ -416,6 +416,7 @@ void Model::setURL(const QUrl& url, const QUrl& fallback, bool retainCurrent, bo
 
     // if so instructed, keep the current geometry until the new one is loaded 
     _nextBaseGeometry = _nextGeometry = Application::getInstance()->getGeometryCache()->getGeometry(url, fallback, delayLoad);
+    _nextLODHysteresis = NetworkGeometry::NO_HYSTERESIS;
     if (!retainCurrent || !isActive() || _nextGeometry->isLoaded()) {
         applyNextGeometry();
     }
@@ -784,7 +785,7 @@ void Model::applyCollision(CollisionInfo& collision) {
 QVector<Model::JointState> Model::updateGeometry(bool delayLoad) {
     QVector<JointState> newJointStates;
     if (_nextGeometry) {
-        _nextGeometry = _nextGeometry->getLODOrFallback(_lodDistance, _lodHysteresis, delayLoad);
+        _nextGeometry = _nextGeometry->getLODOrFallback(_lodDistance, _nextLODHysteresis, delayLoad);
         if (!delayLoad) {
             _nextGeometry->setLoadPriority(this, -_lodDistance);
             _nextGeometry->ensureLoading();
@@ -827,7 +828,7 @@ void Model::applyNextGeometry() {
     // delete our local geometry and custom textures
     deleteGeometry();
     _dilatedTextures.clear();
-    _lodHysteresis = NetworkGeometry::NO_HYSTERESIS;
+    _lodHysteresis = _nextLODHysteresis;
     
     // we retain a reference to the base geometry so that its reference count doesn't fall to zero
     _baseGeometry = _nextBaseGeometry;
diff --git a/interface/src/renderer/Model.h b/interface/src/renderer/Model.h
index 524bd9dc79..ae28a8e4fe 100644
--- a/interface/src/renderer/Model.h
+++ b/interface/src/renderer/Model.h
@@ -247,6 +247,7 @@ private:
     QSharedPointer<NetworkGeometry> _nextGeometry;
     float _lodDistance;
     float _lodHysteresis;
+    float _nextLODHysteresis;
     
     float _pupilDilation;
     std::vector<float> _blendshapeCoefficients;