Torque3D/Engine/source/scene/culling/sceneCullingState.h
2012-09-19 11:15:01 -04:00

311 lines
13 KiB
C++

//-----------------------------------------------------------------------------
// 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.
//-----------------------------------------------------------------------------
#ifndef _SCENECULLINGSTATE_H_
#define _SCENECULLINGSTATE_H_
#ifndef _SCENEZONECULLINGSTATE_H_
#include "scene/culling/sceneZoneCullingState.h"
#endif
#ifndef _MATHUTIL_FRUSTUM_H_
#include "math/util/frustum.h"
#endif
#ifndef _TVECTOR_H_
#include "core/util/tVector.h"
#endif
#ifndef _SCENECAMERASTATE_H_
#include "scene/sceneCameraState.h"
#endif
#ifndef _DATACHUNKER_H_
#include "core/dataChunker.h"
#endif
#ifndef _BITVECTOR_H_
#include "core/bitVector.h"
#endif
class SceneObject;
class SceneManager;
/// An object that gathers the culling state for a scene.
class SceneCullingState
{
public:
/// Used to disable the somewhat expensive terrain occlusion testing
/// done in during scene culling.
static bool smDisableTerrainOcclusion;
/// Whether to force zone culling to off by default.
static bool smDisableZoneCulling;
/// @name Occluder Restrictions
/// Size restrictions on occlusion culling volumes. Any occlusion volume
/// that does not meet these minimum requirements is not accepted into the
/// rendering state.
///
/// Having independent restrictions on both width and height allows filtering
/// out occluders that might have a lot of area but only by covering very thin
/// stretches of the screen.
/// @{
/// If more than this number of occlusion volumes are added to a ZoneState,
/// then the occlusions volumes corresponding to the smallest amount of screen
/// real estate get dropped such as to never exceed this total number of occlusion
/// volumes.
static U32 smMaxOccludersPerZone;
/// Percentage of camera-space frustum near plane height that an occlusion culler must
/// at least fill in order to not be rejected.
/// @note The height computed for occluders is only an estimate.
static F32 smOccluderMinHeightPercentage;
/// Percentage of camera-space frustum near plane width that an occlusion culler must
/// at least fill in order to not be rejected.
/// @note The width computed for occluders is only an estimate.
static F32 smOccluderMinWidthPercentage;
/// @}
protected:
/// Scene which is being culled.
SceneManager* mSceneManager;
/// The viewing state that defines how the scene is being viewed.
SceneCameraState mCameraState;
/// The root culling volume corresponding to the camera frustum.
SceneCullingVolume mRootVolume;
/// Occluders that have been added to this render state. Adding an occluder does not
/// necessarily result in an occluder volume being added. To not repeatedly try to
/// process the same occluder object, all objects that are added are recorded here.
Vector< SceneObject* > mAddedOccluderObjects;
///
BitVector mZoneVisibilityFlags;
/// ZoneState entries for all zones in the scene.
Vector< SceneZoneCullingState > mZoneStates;
/// Allocator for culling data that can be freed in one go when
/// the culling state is freed.
DataChunker mDataChunker;
/// If true, occlusion checks will not be done against the terrains
/// in the scene.
bool mDisableTerrainOcclusion;
/// If true, all objects will only be tested against the root
/// frustum.
bool mDisableZoneCulling;
public:
///
SceneCullingState( SceneManager* sceneManager,
const SceneCameraState& cameraState );
/// Return the scene which is being culled in this state.
SceneManager* getSceneManager() const { return mSceneManager; }
/// Return the root frustum which is used to set up scene visibility.
const Frustum& getFrustum() const { return getCameraState().getFrustum(); }
/// Return the viewing state that defines how the scene is being viewed.
const SceneCameraState& getCameraState() const { return mCameraState; }
/// Return the root culling volume that corresponds to the camera frustum.
/// @note This volume omits the near and far plane of the frustum's polyhedron
/// as these will be tested separately during culling. Testing them repeatedly
/// just wastes time.
const SceneCullingVolume& getRootVolume() const { return mRootVolume; }
/// @name Visibility and Occlusion
/// @{
enum CullOptions
{
/// Cull objects that have their SceneObject::DisableCullingInEditorFlag set.
/// By default, these objects will not get culled if the editor is active.
CullEditorOverrides = BIT( 0 ),
/// Do not cull objects that are render-disabled.
/// @see SceneObject::isRenderEnabled()
DontCullRenderDisabled = BIT( 1 )
};
/// Cull the given list of objects according to the current culling state.
///
/// @param object Array of objects. This array will be modified in place.
/// @param numObjects Number of objects in @a objects.
/// @param cullOptions Combination of CullOptions.
///
/// @return Number of objects remaining in the list.
U32 cullObjects( SceneObject** objects, U32 numObjects, U32 cullOptions = 0 ) const;
/// Return true if the given object is culled according to the current culling state.
bool isCulled( SceneObject* object ) const { return ( cullObjects( &object, 1 ) == 0 ); }
/// Return true if the given AABB is culled in any of the given zones.
bool isCulled( const Box3F& aabb, const U32* zones, U32 numZones ) const;
/// Return true if the given OBB is culled in any of the given zones.
bool isCulled( const OrientedBox3F& obb, const U32* zones, U32 numZones ) const;
/// Return true if the given sphere is culled in any of the given zones.
bool isCulled( const SphereF& sphere, const U32* zones, U32 numZones ) const;
/// Return true if the given object is occluded according to the current culling state.
bool isOccluded( SceneObject* object ) const;
/// Return true if the given AABB is occluded according to the current culling state.
bool isOccluded( const Box3F& aabb, const U32* zones, U32 numZones ) const;
/// Return true if the given OBB is occluded according to the current culling state.
bool isOccluded( const OrientedBox3F& obb, const U32* zones, U32 numZones ) const;
/// Return true if the given sphere is occluded according to the current culling state.
bool isOccluded( const SphereF& sphere, const U32* zones, U32 numZones ) const;
/// Add the occlusion information contained in the given object.
///
/// @note This should only be called after all positive frustums have been added
/// to the zone state.
void addOccluder( SceneObject* object );
/// Test whether the given object is occluded by any of the terrains
/// in the scene.
bool isOccludedByTerrain( SceneObject* object ) const;
/// Set whether isCulled() should do terrain occlusion checks or not.
void setDisableTerrainOcclusion( bool value ) { mDisableTerrainOcclusion = value; }
/// @}
/// @name Zones
/// @{
/// If true, culling will only be performed against the root frustum
/// and not against frustums of individual zones.
///
/// @note This also disables occluders as these are added to the zone frustums.
bool disableZoneCulling() const { return mDisableZoneCulling; }
void disableZoneCulling( bool value ) { mDisableZoneCulling = value; }
/// Return true if any of the zones that the object is currently are
/// visible.
bool isWithinVisibleZone( SceneObject* object ) const;
/// Return a bit vector with one bit for each zone in the scene. If the bit is set,
/// the zone has includer culling volumes attached to it and thus is visible.
const BitVector& getZoneVisibilityFlags() const { return mZoneVisibilityFlags; }
/// Return the culling state for a particular zone.
/// @param zoneId Numeric ID of zone.
const SceneZoneCullingState& getZoneState( U32 zoneId ) const
{
AssertFatal( zoneId < ( U32 ) mZoneStates.size(), "SceneCullingState::getZoneState - Index out of bounds" );
return mZoneStates[ zoneId ];
}
/// Returns the culling state for a particular zone.
/// @param zoneId Numeric ID of zone.
SceneZoneCullingState& getZoneState( U32 zoneId )
{
return const_cast< SceneZoneCullingState& >( static_cast< const SceneCullingState* >( this )->getZoneState( zoneId ) );
}
/// Add a culling volume to the visibility state of the given zone.
///
/// @param zoneId ID of zone to which to add the given frustum's visibility information.
/// @param volume A culling volume. Note that the data in the volume must have
/// a lifetime at least as long as the culling state.
///
/// @return True if the visibility state of the zone has changed, i.e. if the volume
/// was either added in whole or merged with an existing set of planes. If the visibility
/// state of the zone has not changed, returns false.
bool addCullingVolumeToZone( U32 zoneId, const SceneCullingVolume& volume );
/// Copy the data from the given polyhedron to the culling state, create
/// a new culling volume it and add it to the current culling state of the given zone.
///
/// @param zoneId ID of zone to which to add the given frustum's visibility information.
/// @param type Which type of culling volume to add.
/// @param polyhedron Polyhedron describing the space of the culling volume.
bool addCullingVolumeToZone( U32 zoneId, SceneCullingVolume::Type type, const AnyPolyhedron& polyhedron );
/// Create a new culling volume by extruding the given polygon away from the viewpoint.
///
/// @param vertices Array of polygon vertices.
/// @param numVertices Number of vertices in @a vertices.
/// @param type Type of culling volume to create.
/// @param outVolume (out) Receives the generated volume, if successful.
///
/// @return True if a volume could be generated from the given polygon or false if not.
bool createCullingVolume( const Point3F* vertices, U32 numVertices, SceneCullingVolume::Type type, SceneCullingVolume& outVolume );
/// @}
/// @name Memory Management
///
/// Rather than allocating a lot of individual point and plane data for the culling volumes,
/// it is more efficient to batch allocate chunks of memory and then release all the memory
/// for all culling volumes in one go. This is facilitated by this interface.
///
/// @{
/// Allocate memory from this culling state. The memory is freed when the
/// culling state is destroyed.
void* allocateData( U32 size ) { return mDataChunker.alloc( size ); }
/// Allocate memory for @a num instances of T from this culling state.
template< typename T >
T* allocateData( U32 num ) { return reinterpret_cast< T* >( allocateData( sizeof( T ) * num ) ); }
/// @}
/// Queue debug visualizations of the culling volumes of all currently selected zones
/// (or, if no zone is selected, all volumes in the outdoor zone) to the debug drawer.
void debugRenderCullingVolumes() const;
private:
typedef SceneZoneCullingState::CullingTestResult CullingTestResult;
// Helper methods to avoid code duplication.
template< bool OCCLUDERS_ONLY, typename T > CullingTestResult _test( const T& bounds, const U32* zones, U32 numZones ) const;
template< typename T, typename Iter > CullingTestResult _test
( const T& bounds, Iter iter, const PlaneF& nearPlane, const PlaneF& farPlane ) const;
template< typename T, typename Iter > CullingTestResult _testOccludersOnly( const T& bounds, Iter iter ) const;
};
#endif // !_SCENECULLINGSTATE_H_