Engine directory for ticket #1

Engine/source/scene/culling/sceneZoneCullingState.cpp

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+//-----------------------------------------------------------------------------
+// Copyright (c) 2012 GarageGames, LLC
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//-----------------------------------------------------------------------------
+
+#include "platform/platform.h"
+#include "scene/culling/sceneZoneCullingState.h"
+
+#include "scene/culling/sceneCullingState.h"
+#include "platform/profiler.h"
+
+
+//-----------------------------------------------------------------------------
+
+template< typename T >
+inline SceneZoneCullingState::CullingTestResult SceneZoneCullingState::_testVolumes( T bounds, bool occludersOnly ) const
+{
+   // If we are testing for occlusion only and we don't have any
+   // occlusion volumes, we can early out here.
+
+   if( occludersOnly && !mHaveOccluders )
+      return CullingTestNegative;
+
+   // If we haven't sorted the volumes on this zone state yet,
+   // do so now.
+
+   if( !mHaveSortedVolumes )
+      _sortVolumes();
+
+   // Now go through the volumes in this zone and test them
+   // against the bounds.
+
+   for( CullingVolumeLink* link = mCullingVolumes; link != NULL; link = link->mNext )
+   {
+      const SceneCullingVolume& volume = link->mVolume;
+
+      if( volume.isOccluder() )
+      {
+         if( volume.test( bounds ) )
+            return CullingTestPositiveByOcclusion;
+      }
+      else
+      {
+         // If we are testing for occlusion only, we can early out as soon
+         // as we have reached the first non-inverted volume.
+         if( occludersOnly )
+            return CullingTestNegative;
+
+         if( volume.test( bounds ) )
+            return CullingTestPositiveByInclusion;
+      }
+   }
+
+   return CullingTestNegative;
+}
+
+//-----------------------------------------------------------------------------
+
+SceneZoneCullingState::CullingTestResult SceneZoneCullingState::testVolumes( const Box3F& aabb, bool invertedOnly ) const
+{
+   PROFILE_SCOPE( SceneZoneCullingState_testVolumes );
+   return _testVolumes( aabb, invertedOnly );
+}
+
+//-----------------------------------------------------------------------------
+
+SceneZoneCullingState::CullingTestResult SceneZoneCullingState::testVolumes( const OrientedBox3F& obb, bool invertedOnly ) const
+{
+   PROFILE_SCOPE( SceneZoneCullingState_testVolumes_OBB );
+   return _testVolumes( obb, invertedOnly );
+}
+
+//-----------------------------------------------------------------------------
+
+SceneZoneCullingState::CullingTestResult SceneZoneCullingState::testVolumes( const SphereF& sphere, bool invertedOnly ) const
+{
+   PROFILE_SCOPE( SceneZoneCullingState_testVolumes_Sphere );
+   return _testVolumes( sphere, invertedOnly );
+}
+
+//-----------------------------------------------------------------------------
+
+void SceneZoneCullingState::_sortVolumes() const
+{
+   // First do a pass to gather all occlusion volumes.  These must be put on the
+   // list in front of all inclusion volumes.  Otherwise, an inclusion volume
+   // may test positive when in fact an occlusion volume would reject the object.
+
+   CullingVolumeLink* occluderHead = NULL;
+   CullingVolumeLink* occluderTail = NULL;
+
+   if( mHaveOccluders )
+   {
+      U32 numOccluders = 0;
+
+      for( CullingVolumeLink* current = mCullingVolumes, *prev = NULL; current != NULL; )
+      {
+         CullingVolumeLink* next = current->mNext;
+
+         if( !current->mVolume.isOccluder() )
+            prev = current;
+         else
+         {
+            // Unlink from list.
+
+            if( prev )
+               prev->mNext = next;
+            else
+               mCullingVolumes = next;
+
+            // Sort into list.
+
+            _insertSorted( occluderHead, occluderTail, current );
+            ++ numOccluders;
+         }
+
+         current = next;
+      }
+
+      // If we ended up with more inverted (occlusion) volumes than we want,
+      // chop off any but the first N volumes.  Since we have sorted the volumes
+      // by screen coverage, this will get rid of smallest occlusion volumes.
+
+      if( numOccluders > SceneCullingState::smMaxOccludersPerZone )
+      {
+         CullingVolumeLink* last = occluderHead;
+         for( U32 i = 0; i < ( SceneCullingState::smMaxOccludersPerZone - 1 ); ++ i )
+            last = last->mNext;
+
+         // Chop off rest.  The links are allocated on the chunker
+         // and thus will simply disappear when the state gets deleted.
+
+         last->mNext = NULL;
+         occluderTail = last;
+      }
+   }
+
+   // Now, do a second pass to sort all includer volumes by decreasing screen
+   // real estate so that when testing against them, we test the larger volumes first
+   // and the smaller ones later.
+
+   CullingVolumeLink* includerHead = NULL;
+   CullingVolumeLink* includerTail = NULL;
+
+   while( mCullingVolumes )
+   {
+      CullingVolumeLink* current = mCullingVolumes;
+
+      AssertFatal( !current->mVolume.isOccluder(),
+         "SceneCullingState::ZoneState::_sortFrustums - Occluders must have been filtered out at this point" );
+
+      // Unlink from list.
+
+      mCullingVolumes = current->mNext;
+
+      // Sort into list.
+
+      _insertSorted( includerHead, includerTail, current );
+   }
+
+   // Merge the two lists.  Put inverted volumes first and
+   // non-inverted volumes second.
+
+   if( occluderHead != NULL )
+   {
+      mCullingVolumes = occluderHead;
+      occluderTail->mNext = includerHead;
+   }
+   else
+      mCullingVolumes = includerHead;
+
+   // Done.
+
+   mHaveSortedVolumes = true;
+}
+
+//-----------------------------------------------------------------------------
+
+void SceneZoneCullingState::_insertSorted( CullingVolumeLink*& head, CullingVolumeLink*& tail, CullingVolumeLink* link )
+{
+   // If first element, just put it in the list
+   // and return.
+
+   if( !head )
+   {
+      head = link;
+      tail = link;
+      link->mNext = NULL;
+
+      return;
+   }
+
+   // Otherwise, search for where to put it.
+
+   F32 sortPoint = link->mVolume.getSortPoint();
+
+   for( CullingVolumeLink* current = head, *prev = NULL; current != NULL; prev = current, current = current->mNext )
+   {
+      F32 currentSortPoint = current->mVolume.getSortPoint();
+      if( currentSortPoint > sortPoint )
+         continue;
+
+      if( !prev )
+         head = link;
+      else
+         prev->mNext = link;
+
+      link->mNext = current;
+      return;
+   }
+
+   // Smallest frustum in list.  Append to end.
+
+   tail->mNext = link;
+   link->mNext = NULL;
+
+   tail = link;
+}