Make transition in 'auto switch shoulder' smoother.

apps/openmw/mwrender/camera.cpp

@@ -64,7 +64,8 @@ namespace MWRender
       mCameraDistance(0.f),
       mFocalPointCurrentOffset(osg::Vec2d()),
       mFocalPointTargetOffset(osg::Vec2d()),
-      mFocalPointTransitionSpeed(1.f),
+      mFocalPointTransitionSpeedCoef(1.f),
+      mPreviousTransitionInfluence(0.f),
       mSmoothedSpeed(0.f),
       mDynamicCameraDistanceEnabled(false),
       mShowCrosshairInThirdPersonMode(false)
@@ -221,16 +222,44 @@ namespace MWRender
         mSmoothedSpeed += osg::clampBetween(speed - mSmoothedSpeed, -maxDelta, maxDelta);
     }
 
+    void Camera::setFocalPointTargetOffset(osg::Vec2d v)
+    {
+        mFocalPointTargetOffset = v;
+        mPreviousTransitionSpeed = mFocalPointTransitionSpeed;
+        mPreviousTransitionInfluence = 1.0f;
+    }
+
     void Camera::updateFocalPointOffset(float duration)
     {
+        if (duration <= 0)
+            return;
+
+        osg::Vec2d oldOffset = mFocalPointCurrentOffset;
+
+        if (mPreviousTransitionInfluence > 0)
+        {
+            mFocalPointCurrentOffset -= mPreviousExtraOffset;
+            mPreviousExtraOffset = mPreviousExtraOffset / mPreviousTransitionInfluence + mPreviousTransitionSpeed * duration;
+            mPreviousTransitionInfluence =
+                std::max(0.f, mPreviousTransitionInfluence - duration * mFocalPointTransitionSpeedCoef);
+            mPreviousExtraOffset *= mPreviousTransitionInfluence;
+            mFocalPointCurrentOffset += mPreviousExtraOffset;
+        }
+
         osg::Vec2d delta = mFocalPointTargetOffset - mFocalPointCurrentOffset;
         if (delta.length2() > 0)
         {
-            float coef = duration * (1.0 + 5.0 / delta.length()) * mFocalPointTransitionSpeed;
+            float coef = duration * (1.0 + 5.0 / delta.length()) *
+                         mFocalPointTransitionSpeedCoef * (1.0f - mPreviousTransitionInfluence);
             mFocalPointCurrentOffset += delta * std::min(coef, 1.0f);
         }
         else
-            mFocalPointTransitionSpeed = 1.f;
+        {
+            mPreviousExtraOffset = osg::Vec2d();
+            mPreviousTransitionInfluence = 0.f;
+        }
+
+        mFocalPointTransitionSpeed = (mFocalPointCurrentOffset - oldOffset) / duration;
     }
 
     void Camera::toggleViewMode(bool force)

apps/openmw/mwrender/camera.hpp

@@ -58,7 +58,13 @@ namespace MWRender
         osg::Vec3d mFocalPointAdjustment;
         osg::Vec2d mFocalPointCurrentOffset;
         osg::Vec2d mFocalPointTargetOffset;
-        float mFocalPointTransitionSpeed;
+        float mFocalPointTransitionSpeedCoef;
+
+        // This fields are used to make focal point transition smooth if previous transition was not finished.
+        float mPreviousTransitionInfluence;
+        osg::Vec2d mFocalPointTransitionSpeed;
+        osg::Vec2d mPreviousTransitionSpeed;
+        osg::Vec2d mPreviousExtraOffset;
 
         float mSmoothedSpeed;
         bool mDynamicCameraDistanceEnabled;
@@ -75,8 +81,8 @@ namespace MWRender
 
         MWWorld::Ptr getTrackingPtr() const;
 
-        void setFocalPointTransitionSpeed(float v) { mFocalPointTransitionSpeed = v; }
-        void setFocalPointTargetOffset(osg::Vec2d v) { mFocalPointTargetOffset = v; }
+        void setFocalPointTransitionSpeed(float v) { mFocalPointTransitionSpeedCoef = v; }
+        void setFocalPointTargetOffset(osg::Vec2d v);
         void enableDynamicCameraDistance(bool v) { mDynamicCameraDistanceEnabled = v; }
         void enableCrosshairInThirdPersonMode(bool v) { mShowCrosshairInThirdPersonMode = v; }
 

apps/openmw/mwrender/viewovershoulder.cpp

@@ -28,6 +28,7 @@ namespace MWRender
 
         mCamera->enableDynamicCameraDistance(true);
         mCamera->enableCrosshairInThirdPersonMode(true);
+        mCamera->setFocalPointTargetOffset({mOverShoulderHorizontalOffset, mOverShoulderVerticalOffset});
     }
 
     void ViewOverShoulderController::update()
@@ -35,27 +36,23 @@ namespace MWRender
         if (mCamera->isVanityOrPreviewModeEnabled() || mCamera->isFirstPerson())
             return;
 
-        Mode newMode = mMode;
+        Mode oldMode = mMode;
         auto ptr = mCamera->getTrackingPtr();
         if (ptr.getClass().isActor() && ptr.getClass().getCreatureStats(ptr).getDrawState() != MWMechanics::DrawState_Nothing)
-            newMode = Mode::Combat;
+            mMode = Mode::Combat;
         else if (MWBase::Environment::get().getWorld()->isSwimming(ptr))
-            newMode = Mode::Swimming;
-        else if (mMode == Mode::Combat || mMode == Mode::Swimming)
-            newMode = mDefaultShoulderIsRight ? Mode::RightShoulder : Mode::LeftShoulder;
-        if (newMode != mMode)
-        {
-            if (newMode == Mode::Combat || mMode == Mode::Combat)
-                mCamera->setFocalPointTransitionSpeed(5.f);
-            else
-                mCamera->setFocalPointTransitionSpeed(1.f);
-            mMode = newMode;
-        }
-
+            mMode = Mode::Swimming;
+        else if (oldMode == Mode::Combat || oldMode == Mode::Swimming)
+            mMode = mDefaultShoulderIsRight ? Mode::RightShoulder : Mode::LeftShoulder;
         if (mAutoSwitchShoulder && (mMode == Mode::LeftShoulder || mMode == Mode::RightShoulder))
             trySwitchShoulder();
+        if (oldMode == mMode) return;
+
+        if (oldMode == Mode::Combat || mMode == Mode::Combat)
+            mCamera->setFocalPointTransitionSpeed(5.f);
+        else
+            mCamera->setFocalPointTransitionSpeed(1.f);
 
-        osg::Vec2d focalPointTargetOffset;
         switch (mMode)
         {
         case Mode::RightShoulder: