SceneZoneCullingState

Engine/source/scene/culling/sceneZoneCullingState.h

Culling state for a zone.

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Classes:

class

SceneZoneCullingState::CullingVolumeIterator

Iterator over the culling volumes assigned to a zone.

class

SceneZoneCullingState::CullingVolumeLink

A culling volume linked to a zone.

Public Types

enum

CullingTestResult {
  CullingTestPositiveByInclusion 
  CullingTestPositiveByOcclusion 
  CullingTestNegative 
}

Result of a culling test in a zone.

Public Friends

class

SceneCullingState

Protected Attributes

bool

mCanShortcuit

Whether tests can be short-circuited, i.e.

CullingVolumeLink *

mCullingVolumes

Link of culling volumes defining the visibility state of the zone.

bool

mHaveIncluders

Whether there are inclusion volumes on this state.

bool

mHaveOccluders

Whether there are occlusion volumes on this state.

bool

mHaveSortedVolumes

Whether culling volumes for this zone state have already been sorted.

Protected Functions

void

_sortVolumes()

Sort the culling volumes such that the volumes with the highest probability of rejecting objects come first in the list.

CullingTestResult

_testVolumes(T bounds, bool occludersOnly)

Culling volume test abstracted over bounding volume type.

Protected Static Functions

void

_insertSorted(CullingVolumeLink *& head, CullingVolumeLink *& tail, CullingVolumeLink * link)

Insert the volume in link at the proper position in the list represented by head and tail.

Public Functions

SceneZoneCullingState()

Zone states are constructed by SceneCullingState.

CullingVolumeLink *

getCullingVolumes()

Return the list of culling volumes attached to the zone.

bool

hasIncluders()

Return true if the zone has inclusion volumes assigned to it.

bool

hasMultipleVolumes()

Return true if the zone has more than one culling volume assigned to it.

bool

hasOccluders()

Return true if the zone has occlusion volumes assigned to it.

bool

isZoneVisible()

Return true if the zone is visible.

CullingTestResult

testVolumes(const Box3F & aabb, bool occludersOnly)

Test whether the culling volumes added to the zone test positive on the given AABB, i.e.

CullingTestResult

testVolumes(const OrientedBox3F & obb, bool occludersOnly)

Test whether the culling volumes added to the zone test positive on the given OBB, i.e.

CullingTestResult

testVolumes(const SphereF & sphere, bool occludersOnly)

Test whether the culling volumes added to the zone test positive on the given sphere, i.e.

Detailed Description

Culling state for a zone.

Zone states keep track of the culling volumes that are generated during traversal for a particular zone in a scene.

note:
This class has no meaningful constructor; the memory for all zone states is cleared en bloc.

Public Types

CullingTestResult

Enumerator

CullingTestPositiveByInclusion: An includer tested positive on the bounding volume.
CullingTestPositiveByOcclusion: An occluder tested positive on the bounding volume.
CullingTestNegative: None of the culling volumes included or excluded the bounding volume.

Result of a culling test in a zone.

Public Friends

Protected Attributes

bool mCanShortcuit

Whether tests can be short-circuited, i.e.

the first culler that rejects or accepts will cause the test to terminate. This is the case if there are no includers inside occluders, i.e. if occluders can be trusted to fully exclude any space they cover.

CullingVolumeLink * mCullingVolumes

Link of culling volumes defining the visibility state of the zone.

Since there may be multiple portals leading into a zone or multiple occluders inside a zone, we may have multiple culling volumes.

bool mHaveIncluders

Whether there are inclusion volumes on this state.

bool mHaveOccluders

Whether there are occlusion volumes on this state.

bool mHaveSortedVolumes

Whether culling volumes for this zone state have already been sorted.

Protected Functions

_sortVolumes()

Sort the culling volumes such that the volumes with the highest probability of rejecting objects come first in the list.

Also, make sure that all occluders come before all includers so that occlusion is handled correctly.

_testVolumes(T bounds, bool occludersOnly)

Culling volume test abstracted over bounding volume type.

Protected Static Functions

_insertSorted(CullingVolumeLink *& head, CullingVolumeLink *& tail, CullingVolumeLink * link)

Insert the volume in link at the proper position in the list represented by head and tail.

Public Functions

SceneZoneCullingState()

Zone states are constructed by SceneCullingState.

This constructor should not be used otherwise. It is public due to the use through Vector in SceneCullingState.

getCullingVolumes()

Return the list of culling volumes attached to the zone.

hasIncluders()

Return true if the zone has inclusion volumes assigned to it.

hasMultipleVolumes()

Return true if the zone has more than one culling volume assigned to it.

hasOccluders()

Return true if the zone has occlusion volumes assigned to it.

isZoneVisible()

Return true if the zone is visible.

This is the case if any includers have been added to the zone's rendering state.

testVolumes(const Box3F & aabb, bool occludersOnly)

Test whether the culling volumes added to the zone test positive on the given AABB, i.e.

whether they include or exclude the given AABB.

testVolumes(const OrientedBox3F & obb, bool occludersOnly)

Test whether the culling volumes added to the zone test positive on the given OBB, i.e.

whether they include or exclude the given OBB.

Parameters:

obb	An OBB described by 8 points.
invertedOnly	If true, only inverted cullers are tested.

testVolumes(const SphereF & sphere, bool occludersOnly)

Test whether the culling volumes added to the zone test positive on the given sphere, i.e.

whether they include or exclude the given sphere.