/* ----------------------------------------------------------------------------- This source file is part of OGRE (Object-oriented Graphics Rendering Engine) For the latest info, see http://www.ogre3d.org/ Copyright (c) 2000-2013 Torus Knot Software Ltd 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 __ShadowCaster_H__ #define __ShadowCaster_H__ #include "OgrePrerequisites.h" #include "OgreRenderable.h" #include "OgreHeaderPrefix.h" namespace Ogre { /** \addtogroup Core * @{ */ /** \addtogroup Scene * @{ */ /** Class which represents the renderable aspects of a set of shadow volume faces. @remarks Note that for casters comprised of more than one set of vertex buffers (e.g. SubMeshes each using their own geometry), it will take more than one ShadowRenderable to render the shadow volume. Therefore for shadow caster geometry, it is best to stick to one set of vertex buffers (not necessarily one buffer, but the positions for the entire geometry should come from one buffer if possible) */ class _OgreExport ShadowRenderable : public Renderable, public ShadowDataAlloc { protected: MaterialPtr mMaterial; RenderOperation mRenderOp; ShadowRenderable* mLightCap; /// Used only if isLightCapSeparate == true public: ShadowRenderable() : mMaterial(), mLightCap(0) {} virtual ~ShadowRenderable() { delete mLightCap; } /** Set the material to be used by the shadow, should be set by the caller before adding to a render queue */ void setMaterial(const MaterialPtr& mat) { mMaterial = mat; } /// @copydoc Renderable::getMaterial const MaterialPtr& getMaterial(void) const { return mMaterial; } /// @copydoc Renderable::getRenderOperation void getRenderOperation(RenderOperation& op) { op = mRenderOp; } /// Get the internal render operation for set up. RenderOperation* getRenderOperationForUpdate(void) {return &mRenderOp;} /// @copydoc Renderable::getWorldTransforms void getWorldTransforms(Matrix4* xform) const = 0; /// @copydoc Renderable::getSquaredViewDepth Real getSquaredViewDepth(const Camera*) const{ return 0; /* not used */} /// @copydoc Renderable::getLights. const LightList& getLights(void) const; /** Does this renderable require a separate light cap? @remarks If possible, the light cap (when required) should be contained in the usual geometry of the shadow renderable. However, if for some reason the normal depth function (less than) could cause artefacts, then a separate light cap with a depth function of 'always fail' can be used instead. The primary example of this is when there are floating point inaccuracies caused by calculating the shadow geometry separately from the real geometry. */ bool isLightCapSeparate(void) const { return mLightCap != 0; } /// Get the light cap version of this renderable. ShadowRenderable* getLightCapRenderable(void) { return mLightCap; } /// Should this ShadowRenderable be treated as visible? virtual bool isVisible(void) const { return true; } /** This function informs the shadow renderable that the global index buffer from the SceneManager has been updated. As all shadow use this buffer their pointer must be updated as well. @param indexBuffer Pointer to the new index buffer. */ virtual void rebindIndexBuffer(const HardwareIndexBufferSharedPtr& indexBuffer) = 0; }; /** A set of flags that can be used to influence ShadowRenderable creation. */ enum ShadowRenderableFlags { /// For shadow volume techniques only, generate a light cap on the volume. SRF_INCLUDE_LIGHT_CAP = 0x00000001, /// For shadow volume techniques only, generate a dark cap on the volume. SRF_INCLUDE_DARK_CAP = 0x00000002, /// For shadow volume techniques only, indicates volume is extruded to infinity. SRF_EXTRUDE_TO_INFINITY = 0x00000004 }; /** This class defines the interface that must be implemented by shadow casters. */ class _OgreExport ShadowCaster { public: virtual ~ShadowCaster() { } /** Returns whether or not this object currently casts a shadow. */ virtual bool getCastShadows(void) const = 0; /** Returns details of the edges which might be used to determine a silhouette. */ virtual EdgeData* getEdgeList(void) = 0; /** Returns whether the object has a valid edge list. */ virtual bool hasEdgeList(void) = 0; /** Get the world bounding box of the caster. */ virtual const AxisAlignedBox& getWorldBoundingBox(bool derive = false) const = 0; /** Gets the world space bounding box of the light cap. */ virtual const AxisAlignedBox& getLightCapBounds(void) const = 0; /** Gets the world space bounding box of the dark cap, as extruded using the light provided. */ virtual const AxisAlignedBox& getDarkCapBounds(const Light& light, Real dirLightExtrusionDist) const = 0; typedef vector::type ShadowRenderableList; typedef VectorIterator ShadowRenderableListIterator; /** 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. @param shadowTechnique The technique being used to generate the shadow. @param light The light to generate the shadow from. @param indexBuffer The index buffer to build the renderables into, the current contents are assumed to be disposable. @param extrudeVertices If @c 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). @param extrusionDistance The distance to extrude the shadow volume. @param flags Technique-specific flags, see ShadowRenderableFlags. */ virtual ShadowRenderableListIterator getShadowVolumeRenderableIterator( ShadowTechnique shadowTechnique, const Light* light, HardwareIndexBufferSharedPtr* indexBuffer, size_t* indexBufferUsedSize, bool extrudeVertices, Real extrusionDistance, unsigned long flags = 0 ) = 0; /** 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. @param vertexBuffer The vertex buffer containing ONLY xyz position values, which must be originalVertexCount * 2 * 3 floats long. @param 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. @param lightPos 4D light position in object space, when w=0.0f this represents a directional light. @param extrudeDist The distance to extrude. */ static void extrudeVertices(const HardwareVertexBufferSharedPtr& vertexBuffer, size_t originalVertexCount, const Vector4& lightPos, Real extrudeDist); /** Get the distance to extrude for a point/spot light. */ virtual Real getPointExtrusionDistance(const Light* l) const = 0; protected: /// Helper method for calculating extrusion distance. Real getExtrusionDistance(const Vector3& objectPos, const Light* light) const; /** 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. @param edgeData The edge information to update. @param lightPos 4D vector representing the light, a directional light has w=0.0. */ virtual void updateEdgeListLightFacing(EdgeData* edgeData, const Vector4& lightPos); /** Generates the indexes required to render a shadow volume into the index buffer which is passed in, and updates shadow renderables to use it. @param edgeData The edge information to use. @param indexBuffer The buffer into which to write data into; current contents are assumed to be discardable. @param 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. @param light The light, mainly for type info as silhouette calculations should already have been done in updateEdgeListLightFacing @param shadowRenderables A list of shadow renderables which has already been constructed but will need populating with details of the index ranges to be used. @param flags Additional controller flags, see ShadowRenderableFlags. */ virtual void generateShadowVolume(EdgeData* edgeData, const HardwareIndexBufferSharedPtr& indexBuffer, size_t& indexBufferUsedSize, const Light* light, ShadowRenderableList& shadowRenderables, unsigned long flags); /** Utility method for extruding a bounding box. @param box Original bounding box, will be updated in-place. @param lightPos 4D light position in object space, when w=0.0f this represents a directional light. @param extrudeDist The distance to extrude. */ virtual void extrudeBounds(AxisAlignedBox& box, const Vector4& lightPos, Real extrudeDist) const; }; /** @} */ /** @} */ } // namespace Ogre #include "OgreHeaderSuffix.h" #endif // __ShadowCaster_H__