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Ogre::PatchSurface Class Reference

A surface which is defined by curves of some kind to form a patch, e.g. More...

#include <OgrePatchSurface.h>

List of all members.

Public Types

enum  PatchSurfaceType { PST_BEZIER }
enum  { AUTO_LEVEL = -1 }
 Constant for indicating automatic determination of subdivision level for patches. More...

enum  VisibleSide { VS_FRONT, VS_BACK, VS_BOTH }

Public Member Functions

 PatchSurface ()
 ~PatchSurface ()
void defineSurface (void *controlPointBuffer, VertexDeclaration *declaration, size_t width, size_t height, PatchSurfaceType pType=PST_BEZIER, size_t uMaxSubdivisionLevel=AUTO_LEVEL, size_t vMaxSubdivisionLevel=AUTO_LEVEL, VisibleSide visibleSide=VS_FRONT)
 Sets up the surface by defining it's control points, type and initial subdivision level.

size_t getRequiredVertexCount (void) const
 Based on a previous call to defineSurface, establishes the number of vertices required to hold this patch at the maximum detail level.

size_t getRequiredIndexCount (void) const
 Based on a previous call to defineSurface, establishes the number of indexes required to hold this patch at the maximum detail level.

size_t getCurrentIndexCount (void) const
 Gets the current index count based on the current subdivision level.

size_t getIndexOffset (void) const
 Returns the index offset used by this buffer to write data into the buffer.

size_t getVertexOffset (void) const
 Returns the vertex offset used by this buffer to write data into the buffer.

const AxisAlignedBox & getBounds (void) const
 Gets the bounds of this patch, only valid after calling defineSurface.

Real getBoundingSphereRadius (void) const
 Gets the radius of the bounding sphere for this patch, only valid after defineSurface has been called.

void build (HardwareVertexBufferSharedPtr destVertexBuffer, size_t vertexStart, HardwareIndexBufferSharedPtr destIndexBuffer, size_t indexStart)
 Tells the system to build the mesh relating to the surface into externally created buffers.

void setSubdivisionFactor (Real factor)
 Alters the level of subdivision for this surface.

Real getSubdivisionFactor (void) const
 Gets the current level of subdivision.

void * getControlPointBuffer (void) const
void notifyControlPointBufferDeallocated (void)
 Convenience method for telling the patch that the control points have been deleted, since once the patch has been built they are not required.


Protected Member Functions

size_t findLevel (Vector3 &a, Vector3 &b, Vector3 &c)
 Internal method for finding the subdivision level given 3 control points.

void distributeControlPoints (void *lockedBuffer)
void subdivideCurve (void *lockedBuffer, size_t startIdx, size_t stepSize, size_t numSteps, size_t iterations)
void interpolateVertexData (void *lockedBuffer, size_t leftIndex, size_t rightIndex, size_t destIndex)
void makeTriangles (void)
size_t getAutoULevel (bool forMax=false)
size_t getAutoVLevel (bool forMax=false)

Protected Attributes

VertexDeclaration * mDeclaration
 Vertex declaration describing the control point buffer.

void * mControlPointBuffer
 Buffer containing the system-memory control points.

PatchSurfaceType mType
 Type of surface.

size_t mCtlWidth
 Width in control points.

size_t mCtlHeight
 Height in control points.

size_t mCtlCount
 TotalNumber of control points.

size_t mULevel
 U-direction subdivision level.

size_t mVLevel
 V-direction subdivision level.

size_t mMaxULevel
 Max subdivision level.

size_t mMaxVLevel
size_t mMeshWidth
 Width of the subdivided mesh (big enough for max level).

size_t mMeshHeight
 Height of the subdivided mesh (big enough for max level).

VisibleSide mVSide
 Which side is visible.

Real mSubdivisionFactor
std::vector< Vector3 > mVecCtlPoints
HardwareVertexBufferSharedPtr mVertexBuffer
HardwareIndexBufferSharedPtr mIndexBuffer
size_t mVertexOffset
size_t mIndexOffset
size_t mRequiredVertexCount
size_t mRequiredIndexCount
size_t mCurrIndexCount
AxisAlignedBox mAABB
Real mBoundingSphere

Detailed Description

A surface which is defined by curves of some kind to form a patch, e.g.

a Bezier patch.

Remarks:
This object will take a list of control points with various assorted data, and will subdivide it into a patch mesh. Currently only Bezier curves are supported for defining the surface, but other techniques such as NURBS would follow the same basic approach.

Definition at line 43 of file OgrePatchSurface.h.

Member Enumeration Documentation

anonymous enum
 

Constant for indicating automatic determination of subdivision level for patches.

Enumeration values:
AUTO_LEVEL 

Definition at line 56 of file OgrePatchSurface.h.

enum Ogre::PatchSurface::PatchSurfaceType
 

Enumeration values:
PST_BEZIER  A patch defined by a set of bezier curves.

Definition at line 49 of file OgrePatchSurface.h.

enum Ogre::PatchSurface::VisibleSide
 

Enumeration values:
VS_FRONT  The side from which u goes right and v goes up (as in texture coords).
VS_BACK  The side from which u goes right and v goes down (reverse of texture coords).
VS_BOTH  Both sides are visible - warning this creates 2x the number of triangles and adds extra overhead for calculating normals.

Definition at line 61 of file OgrePatchSurface.h.

Constructor & Destructor Documentation

Ogre::PatchSurface::PatchSurface (   ) 
 

Ogre::PatchSurface::~PatchSurface (   ) 
 

Member Function Documentation

void Ogre::PatchSurface::build (  HardwareVertexBufferSharedPtr  destVertexBuffer,
size_t  vertexStart,
HardwareIndexBufferSharedPtr  destIndexBuffer,
size_t  indexStart
) 
 

Tells the system to build the mesh relating to the surface into externally created buffers.

Remarks:
The VertexDeclaration of the vertex buffer must be identical to the one passed into defineSurface. In addition, there must be enough space in the buffer to accommodate the patch at full detail level; you should call getRequiredVertexCount and getRequiredIndexCount to determine this. This method does not create an internal mesh for this patch and so getMesh will return null if you call it after building the patch this way.
Parameters:
destVertexBuffer The destination vertex buffer in which to build the patch.
vertexStart The offset at which to start writing vertices for this patch
destIndexBuffer The destination index buffer in which to build the patch.
vertexStart The offset at which to start writing indexes for this patch

void Ogre::PatchSurface::defineSurface (  void *  controlPointBuffer,
VertexDeclaration *  declaration,
size_t  width,
size_t  height,
PatchSurfaceType  pType = PST_BEZIER,
size_t  uMaxSubdivisionLevel = AUTO_LEVEL,
size_t  vMaxSubdivisionLevel = AUTO_LEVEL,
VisibleSide  visibleSide = VS_FRONT
) 
 

Sets up the surface by defining it's control points, type and initial subdivision level.

Remarks:
This method initialises the surface by passing it a set of control points. The type of curves to be used are also defined here, although the only supported option currently is a bezier patch. You can also specify a global subdivision level here if you like, although it is recommended that the parameter is left as AUTO_LEVEL, which means the system decides how much subdivision is required (based on the curvature of the surface)
Parameters:
controlPointBuffer A pointer to a buffer containing the vertex data which defines control points of the curves rather than actual vertices. Note that you are expected to provide not just position information, but potentially normals and texture coordinates too. The format of the buffer is defined in the VertexDeclaration parameter
decaration VertexDeclaration describing the contents of the buffer. Note this declaration must _only_ draw on buffer source 0!
width Specifies the width of the patch in control points.
height Specifies the height of the patch in control points.
pType The type of surface - currently only PST_BEZIER is supported
uMaxSubdivisionLevel,vMaxSubdivisionLevel If you want to manually set the top level of subdivision, do it here, otherwise let the system decide.
visibleSide Determines which side of the patch (or both) triangles are generated for.

void Ogre::PatchSurface::distributeControlPoints (  void *  lockedBuffer  )  [protected]
 

size_t Ogre::PatchSurface::findLevel (  Vector3 &  a,
Vector3 &  b,
Vector3 &  c
)  [protected]
 

Internal method for finding the subdivision level given 3 control points.

size_t Ogre::PatchSurface::getAutoULevel (  bool  forMax = false  )  [protected]
 

size_t Ogre::PatchSurface::getAutoVLevel (  bool  forMax = false  )  [protected]
 

Real Ogre::PatchSurface::getBoundingSphereRadius (  void   )  const
 

Gets the radius of the bounding sphere for this patch, only valid after defineSurface has been called.

const AxisAlignedBox& Ogre::PatchSurface::getBounds (  void   )  const
 

Gets the bounds of this patch, only valid after calling defineSurface.

void* Ogre::PatchSurface::getControlPointBuffer (  void   )  const
 

Definition at line 159 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::getCurrentIndexCount (  void   )  const
 

Gets the current index count based on the current subdivision level.

size_t Ogre::PatchSurface::getIndexOffset (  void   )  const
 

Returns the index offset used by this buffer to write data into the buffer.

Definition at line 118 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::getRequiredIndexCount (  void   )  const
 

Based on a previous call to defineSurface, establishes the number of indexes required to hold this patch at the maximum detail level.

Remarks:
This is useful when you wish to build the patch into external vertex / index buffers.

size_t Ogre::PatchSurface::getRequiredVertexCount (  void   )  const
 

Based on a previous call to defineSurface, establishes the number of vertices required to hold this patch at the maximum detail level.

Remarks:
This is useful when you wish to build the patch into external vertex / index buffers.

Real Ogre::PatchSurface::getSubdivisionFactor (  void   )  const
 

Gets the current level of subdivision.

size_t Ogre::PatchSurface::getVertexOffset (  void   )  const
 

Returns the vertex offset used by this buffer to write data into the buffer.

Definition at line 120 of file OgrePatchSurface.h.

void Ogre::PatchSurface::interpolateVertexData (  void *  lockedBuffer,
size_t  leftIndex,
size_t  rightIndex,
size_t  destIndex
)  [protected]
 

void Ogre::PatchSurface::makeTriangles (  void   )  [protected]
 

void Ogre::PatchSurface::notifyControlPointBufferDeallocated (  void   ) 
 

Convenience method for telling the patch that the control points have been deleted, since once the patch has been built they are not required.

Definition at line 165 of file OgrePatchSurface.h.

void Ogre::PatchSurface::setSubdivisionFactor (  Real  factor  ) 
 

Alters the level of subdivision for this surface.

Remarks:
This method changes the proportionate detail level of the patch; since the U and V directions can have different subdivision levels, this method takes a single Real value where 0 is the minimum detail (the control points) and 1 is the maximum detail level as supplied to the original call to defineSurface.

void Ogre::PatchSurface::subdivideCurve (  void *  lockedBuffer,
size_t  startIdx,
size_t  stepSize,
size_t  numSteps,
size_t  iterations
)  [protected]
 

Member Data Documentation

AxisAlignedBox Ogre::PatchSurface::mAABB [protected]
 

Definition at line 219 of file OgrePatchSurface.h.

Real Ogre::PatchSurface::mBoundingSphere [protected]
 

Definition at line 220 of file OgrePatchSurface.h.

void* Ogre::PatchSurface::mControlPointBuffer [protected]
 

Buffer containing the system-memory control points.

Definition at line 172 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCtlCount [protected]
 

TotalNumber of control points.

Definition at line 180 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCtlHeight [protected]
 

Height in control points.

Definition at line 178 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCtlWidth [protected]
 

Width in control points.

Definition at line 176 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCurrIndexCount [protected]
 

Definition at line 217 of file OgrePatchSurface.h.

VertexDeclaration* Ogre::PatchSurface::mDeclaration [protected]
 

Vertex declaration describing the control point buffer.

Definition at line 170 of file OgrePatchSurface.h.

HardwareIndexBufferSharedPtr Ogre::PatchSurface::mIndexBuffer [protected]
 

Definition at line 212 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mIndexOffset [protected]
 

Definition at line 214 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMaxULevel [protected]
 

Max subdivision level.

Definition at line 186 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMaxVLevel [protected]
 

Definition at line 187 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMeshHeight [protected]
 

Height of the subdivided mesh (big enough for max level).

Definition at line 191 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMeshWidth [protected]
 

Width of the subdivided mesh (big enough for max level).

Definition at line 189 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mRequiredIndexCount [protected]
 

Definition at line 216 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mRequiredVertexCount [protected]
 

Definition at line 215 of file OgrePatchSurface.h.

Real Ogre::PatchSurface::mSubdivisionFactor [protected]
 

Definition at line 195 of file OgrePatchSurface.h.

PatchSurfaceType Ogre::PatchSurface::mType [protected]
 

Type of surface.

Definition at line 174 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mULevel [protected]
 

U-direction subdivision level.

Definition at line 182 of file OgrePatchSurface.h.

std::vector<Vector3> Ogre::PatchSurface::mVecCtlPoints [protected]
 

Definition at line 197 of file OgrePatchSurface.h.

HardwareVertexBufferSharedPtr Ogre::PatchSurface::mVertexBuffer [protected]
 

Definition at line 211 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mVertexOffset [protected]
 

Definition at line 213 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mVLevel [protected]
 

V-direction subdivision level.

Definition at line 184 of file OgrePatchSurface.h.

VisibleSide Ogre::PatchSurface::mVSide [protected]
 

Which side is visible.

Definition at line 193 of file OgrePatchSurface.h.

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

Copyright © 2000-2005 by The OGRE Team
Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sun Mar 12 14:41:38 2006