Ogre::ShadowCaster Class Referenceabstract
Core » Scene

This class defines the interface that must be implemented by shadow casters. More...

`#include <OgreShadowCaster.h>`

Inheritance diagram for Ogre::ShadowCaster:
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## Public Types

typedef vector< ShadowRenderable * >::type | ShadowRenderableList
typedef VectorIterator< ShadowRenderableList > | ShadowRenderableListIterator

## Public Member Functions

virtual | ~ShadowCaster ()
virtual bool | getCastShadows (void) const =0
| Returns whether or not this object currently casts a shadow. More...
virtual const AxisAlignedBox & | getDarkCapBounds (const Light &light, Real dirLightExtrusionDist) const =0
| Gets the world space bounding box of the dark cap, as extruded using the light provided. More...
virtual EdgeData * | getEdgeList (void)=0
| Returns details of the edges which might be used to determine a silhouette. More...
virtual const AxisAlignedBox & | getLightCapBounds (void) const =0
| Gets the world space bounding box of the light cap. More...
virtual Real | getPointExtrusionDistance (const Light *l) const =0
| Get the distance to extrude for a point/spot light. More...
virtual ShadowRenderableListIterator | getShadowVolumeRenderableIterator (ShadowTechnique shadowTechnique, const Light *light, HardwareIndexBufferSharedPtr *indexBuffer, size_t *indexBufferUsedSize, bool extrudeVertices, Real extrusionDistance, unsigned long flags=0)=0
| Gets an iterator over the renderables required to render the shadow volume. More...
virtual const AxisAlignedBox & | getWorldBoundingBox (bool derive=false) const =0
| Get the world bounding box of the caster. More...
virtual bool | hasEdgeList (void)=0
| Returns whether the object has a valid edge list. More...

## Static Public Member Functions

static void | extrudeVertices (const HardwareVertexBufferSharedPtr &vertexBuffer, size_t originalVertexCount, const Vector4 &lightPos, Real extrudeDist)
| Utility method for extruding vertices based on a light. More...

## Protected Member Functions

virtual void | extrudeBounds (AxisAlignedBox &box, const Vector4 &lightPos, Real extrudeDist) const
| Utility method for extruding a bounding box. More...
virtual void | generateShadowVolume (EdgeData *edgeData, const HardwareIndexBufferSharedPtr &indexBuffer, size_t &indexBufferUsedSize, const Light *light, ShadowRenderableList &shadowRenderables, unsigned long flags)
| Generates the indexes required to render a shadow volume into the index buffer which is passed in, and updates shadow renderables to use it. More...
Real | getExtrusionDistance (const Vector3 &objectPos, const Light *light) const
| Helper method for calculating extrusion distance. More...
virtual void | updateEdgeListLightFacing (EdgeData *edgeData, const Vector4 &lightPos)
| Tells the caster to perform the tasks necessary to update the edge data's light listing. More...

## Detailed Description

This class defines the interface that must be implemented by shadow casters.

Definition at line 117 of file OgreShadowCaster.h.

## Member Typedef Documentation

## ShadowRenderableList

typedef vector<ShadowRenderable*>::type Ogre::ShadowCaster::ShadowRenderableList

Definition at line 136 of file OgreShadowCaster.h.

## ShadowRenderableListIterator

typedef VectorIterator<ShadowRenderableList> Ogre::ShadowCaster::ShadowRenderableListIterator

Definition at line 137 of file OgreShadowCaster.h.

## Constructor & Destructor Documentation

## ~ShadowCaster()

virtual Ogre::ShadowCaster::~ShadowCaster | ( |  | ) |

virtual

Definition at line 120 of file OgreShadowCaster.h.

## Member Function Documentation

## extrudeBounds()

virtual void Ogre::ShadowCaster::extrudeBounds | ( | AxisAlignedBox & | box,
|  | const Vector4 & | lightPos,
|  | Real | extrudeDist
| ) |  | const

protected virtual

Utility method for extruding a bounding box.

Parameters

  box | Original bounding box, will be updated in-place.
  lightPos | 4D light position in object space, when w=0.0f this represents a directional light.
  extrudeDist | The distance to extrude.

## extrudeVertices()

static void Ogre::ShadowCaster::extrudeVertices | ( | const HardwareVertexBufferSharedPtr & | vertexBuffer,
|  | size_t | originalVertexCount,
|  | const Vector4 & | lightPos,
|  | Real | extrudeDist
| ) |  |

static

Utility method for extruding vertices based on a light.

Remarks
  Unfortunately, because D3D cannot handle homogeneous (4D) position coordinates in the fixed-function pipeline (GL can, but we have to be cross-API), when we extrude in software we cannot extrude to infinity the way we do in the vertex program (by setting w to 0.0f). Therefore we extrude by a fixed distance, which may cause some problems with larger scenes. Luckily better hardware (ie vertex programs) can fix this.

Parameters

  vertexBuffer | The vertex buffer containing ONLY xyz position values, which must be originalVertexCount * 2 * 3 floats long.
  originalVertexCount | The count of the original number of vertices, i.e. the number in the mesh, not counting the doubling which has already been done (by VertexData::prepareForShadowVolume) to provide the extruded area of the buffer.
  lightPos | 4D light position in object space, when w=0.0f this represents a directional light.
  extrudeDist | The distance to extrude.

## generateShadowVolume()

virtual void Ogre::ShadowCaster::generateShadowVolume | ( | EdgeData * | edgeData,
|  | const HardwareIndexBufferSharedPtr & | indexBuffer,
|  | size_t & | indexBufferUsedSize,
|  | const Light * | light,
|  | ShadowRenderableList & | shadowRenderables,
|  | unsigned long | flags
| ) |  |

protected virtual

Generates the indexes required to render a shadow volume into the index buffer which is passed in, and updates shadow renderables to use it.

Parameters

  edgeData | The edge information to use.
  indexBuffer | The buffer into which to write data into; current contents are assumed to be discardable.
  indexBufferUsedSize | If the rest of buffer is enough than it would be locked with HBL_NO_OVERWRITE semantic and indexBufferUsedSize would be increased, otherwise HBL_DISCARD would be used and indexBufferUsedSize would be reset.
  light | The light, mainly for type info as silhouette calculations should already have been done in updateEdgeListLightFacing
  shadowRenderables | A list of shadow renderables which has already been constructed but will need populating with details of the index ranges to be used.
  flags | Additional controller flags, see ShadowRenderableFlags.

## getCastShadows()

virtual bool Ogre::ShadowCaster::getCastShadows | ( | void |  | ) | const

pure virtual

Returns whether or not this object currently casts a shadow.

Implemented in Ogre::MovableObject, and Ogre::TerrainQuadTreeNode::Movable.

## getDarkCapBounds()

virtual const AxisAlignedBox& Ogre::ShadowCaster::getDarkCapBounds | ( | const Light & | light,
|  | Real | dirLightExtrusionDist
| ) |  | const

pure virtual

Gets the world space bounding box of the dark cap, as extruded using the light provided.

Implemented in Ogre::MovableObject.

## getEdgeList()

virtual EdgeData* Ogre::ShadowCaster::getEdgeList | ( | void |  | ) |

pure virtual

Returns details of the edges which might be used to determine a silhouette.

Implemented in Ogre::Entity, Ogre::MovableObject, Ogre::StaticGeometry::Region, and Ogre::ManualObject.

## getExtrusionDistance()

Real Ogre::ShadowCaster::getExtrusionDistance | ( | const Vector3 & | objectPos,
|  | const Light * | light
| ) |  | const

protected

Helper method for calculating extrusion distance.

## getLightCapBounds()

virtual const AxisAlignedBox& Ogre::ShadowCaster::getLightCapBounds | ( | void |  | ) | const

pure virtual

Gets the world space bounding box of the light cap.

Implemented in Ogre::MovableObject.

## getPointExtrusionDistance()

virtual Real Ogre::ShadowCaster::getPointExtrusionDistance | ( | const Light * | l | ) | const

pure virtual

Get the distance to extrude for a point/spot light.

Implemented in Ogre::MovableObject.

## getShadowVolumeRenderableIterator()

virtual ShadowRenderableListIterator Ogre::ShadowCaster::getShadowVolumeRenderableIterator | ( | ShadowTechnique | shadowTechnique,
|  | const Light * | light,
|  | HardwareIndexBufferSharedPtr * | indexBuffer,
|  | size_t * | indexBufferUsedSize,
|  | bool | extrudeVertices,
|  | Real | extrusionDistance,
|  | unsigned long | flags = `0`
| ) |  |

pure virtual

Gets an iterator over the renderables required to render the shadow volume.

Remarks
  Shadowable geometry should ideally be designed such that there is only one ShadowRenderable required to render the the shadow; however this is not a necessary limitation and it can be exceeded if required.

Parameters

  shadowTechnique | The technique being used to generate the shadow.
  light | The light to generate the shadow from.
  indexBuffer | The index buffer to build the renderables into, the current contents are assumed to be disposable.
  extrudeVertices | If `true`, this means this class should extrude the vertices of the back of the volume in software. If false, it will not be done (a vertex program is assumed).
  extrusionDistance | The distance to extrude the shadow volume.
  flags | Technique-specific flags, see ShadowRenderableFlags.

Implemented in Ogre::Entity, Ogre::MovableObject, Ogre::StaticGeometry::Region, and Ogre::ManualObject.

## getWorldBoundingBox()

virtual const AxisAlignedBox& Ogre::ShadowCaster::getWorldBoundingBox | ( | bool | derive = `false` | ) | const

pure virtual

Get the world bounding box of the caster.

Implemented in Ogre::Entity, and Ogre::MovableObject.

## hasEdgeList()

virtual bool Ogre::ShadowCaster::hasEdgeList | ( | void |  | ) |

pure virtual

Returns whether the object has a valid edge list.

Implemented in Ogre::Entity, Ogre::MovableObject, Ogre::StaticGeometry::Region, and Ogre::ManualObject.

## updateEdgeListLightFacing()

virtual void Ogre::ShadowCaster::updateEdgeListLightFacing | ( | EdgeData * | edgeData,
|  | const Vector4 & | lightPos
| ) |  |

protected virtual

Tells the caster to perform the tasks necessary to update the edge data's light listing.

Can be overridden if the subclass needs to do additional things.

Parameters

  edgeData | The edge information to update.
  lightPos | 4D vector representing the light, a directional light has w=0.0.

The documentation for this class was generated from the following file:

- OgreShadowCaster.h

Copyright © 2012 Torus Knot Software Ltd
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.