From 1a9672e31bcc29642690eccafe0f79e1aaf6d83c Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Tue, 20 Aug 2013 11:31:49 -0700
Subject: [PATCH] Don't update player physics more than 60 times a second

Bullet and/or our collision handling code doesn't like timesteps much
smaller than that. Ideally we should do physics in 60fps (or even 30fps)
steps and use prediction and interpolation to get more, but that's not
straight forward and needs a fixed timestep loop to lock physics and
logic together.
---
 apps/openmw/mwworld/physicssystem.cpp | 29 ++++++++++++++-------------
 apps/openmw/mwworld/physicssystem.hpp |  5 +++--
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/apps/openmw/mwworld/physicssystem.cpp b/apps/openmw/mwworld/physicssystem.cpp
index 558d3f037f..c865629acd 100644
--- a/apps/openmw/mwworld/physicssystem.cpp
+++ b/apps/openmw/mwworld/physicssystem.cpp
@@ -225,7 +225,7 @@ namespace MWWorld
 
 
     PhysicsSystem::PhysicsSystem(OEngine::Render::OgreRenderer &_rend) :
-        mRender(_rend), mEngine(0)
+        mRender(_rend), mEngine(0), mTimeAccum(0.0f)
     {
         // Create physics. shapeLoader is deleted by the physic engine
         NifBullet::ManualBulletShapeLoader* shapeLoader = new NifBullet::ManualBulletShapeLoader();
@@ -394,11 +394,6 @@ namespace MWWorld
         return mEngine->getCollisions(ptr.getRefData().getBaseNode()->getName());
     }
 
-    Ogre::Vector3 PhysicsSystem::move(const MWWorld::Ptr &ptr, const Ogre::Vector3 &movement, float time, bool gravity)
-    {
-        return MovementSolver::move(ptr, movement, time, gravity, mEngine);
-    }
-
     Ogre::Vector3 PhysicsSystem::traceDown(const MWWorld::Ptr &ptr)
     {
         return MovementSolver::traceDown(ptr, mEngine);
@@ -570,16 +565,22 @@ namespace MWWorld
     {
         mMovementResults.clear();
 
-        const MWBase::World *world = MWBase::Environment::get().getWorld();
-        PtrVelocityList::iterator iter = mMovementQueue.begin();
-        for(;iter != mMovementQueue.end();iter++)
+        mTimeAccum += dt;
+        if(mTimeAccum >= 1.0f/60.0f)
         {
-            Ogre::Vector3 newpos;
-            newpos = move(iter->first, iter->second, dt,
-                          !world->isSwimming(iter->first) && !world->isFlying(iter->first));
-            mMovementResults.push_back(std::make_pair(iter->first, newpos));
-        }
+            const MWBase::World *world = MWBase::Environment::get().getWorld();
+            PtrVelocityList::iterator iter = mMovementQueue.begin();
+            for(;iter != mMovementQueue.end();iter++)
+            {
+                Ogre::Vector3 newpos;
+                newpos = MovementSolver::move(iter->first, iter->second, mTimeAccum,
+                                              !world->isSwimming(iter->first) &&
+                                              !world->isFlying(iter->first), mEngine);
+                mMovementResults.push_back(std::make_pair(iter->first, newpos));
+            }
 
+            mTimeAccum = 0.0f;
+        }
         mMovementQueue.clear();
 
         return mMovementResults;
diff --git a/apps/openmw/mwworld/physicssystem.hpp b/apps/openmw/mwworld/physicssystem.hpp
index 438e2ada65..bbee2d5daf 100644
--- a/apps/openmw/mwworld/physicssystem.hpp
+++ b/apps/openmw/mwworld/physicssystem.hpp
@@ -52,8 +52,7 @@ namespace MWWorld
             void scaleObject (const MWWorld::Ptr& ptr);
 
             bool toggleCollisionMode();
-            
-            Ogre::Vector3 move(const MWWorld::Ptr &ptr, const Ogre::Vector3 &movement, float time, bool gravity);
+
             std::vector<std::string> getCollisions(const MWWorld::Ptr &ptr); ///< get handles this object collides with
             Ogre::Vector3 traceDown(const MWWorld::Ptr &ptr);
 
@@ -98,6 +97,8 @@ namespace MWWorld
             PtrVelocityList mMovementQueue;
             PtrVelocityList mMovementResults;
 
+            float mTimeAccum;
+
             PhysicsSystem (const PhysicsSystem&);
             PhysicsSystem& operator= (const PhysicsSystem&);
     };