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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 47 of file OgrePatchSurface.h.

## Member Enumeration Documentation

enum Ogre::PatchSurface::PatchSurfaceType

Enumerator:

  PST_BEZIER | A patch defined by a set of bezier curves.

Definition at line 53 of file OgrePatchSurface.h.

anonymous enum

Constant for indicating automatic determination of subdivision level for patches.

Enumerator:

  AUTO_LEVEL |

Definition at line 60 of file OgrePatchSurface.h.

enum Ogre::PatchSurface::VisibleSide

Enumerator:

  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 65 of file OgrePatchSurface.h.

## Constructor & Destructor Documentation

Ogre::PatchSurface::PatchSurface | ( |  | ) |

Ogre::PatchSurface::~PatchSurface | ( |  | ) |

## Member Function Documentation

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.

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.

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::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 122 of file OgrePatchSurface.h.

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

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

Definition at line 124 of file OgrePatchSurface.h.

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

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

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

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

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::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.

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

Gets the current level of subdivision.

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

Definition at line 163 of file OgrePatchSurface.h.

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 169 of file OgrePatchSurface.h.

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

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

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

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

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

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

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

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

## Member Data Documentation

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

Vertex declaration describing the control point buffer.

Definition at line 174 of file OgrePatchSurface.h.

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

Buffer containing the system-memory control points.

Definition at line 176 of file OgrePatchSurface.h.

PatchSurfaceType Ogre::PatchSurface::mType`[protected]`

Type of surface.

Definition at line 178 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCtlWidth`[protected]`

Width in control points.

Definition at line 180 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCtlHeight`[protected]`

Height in control points.

Definition at line 182 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCtlCount`[protected]`

TotalNumber of control points.

Definition at line 184 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mULevel`[protected]`

U-direction subdivision level.

Definition at line 186 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mVLevel`[protected]`

V-direction subdivision level.

Definition at line 188 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMaxULevel`[protected]`

Max subdivision level.

Definition at line 190 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMaxVLevel`[protected]`

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 193 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mMeshHeight`[protected]`

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

Definition at line 195 of file OgrePatchSurface.h.

VisibleSide Ogre::PatchSurface::mVSide`[protected]`

Which side is visible.

Definition at line 197 of file OgrePatchSurface.h.

Real Ogre::PatchSurface::mSubdivisionFactor`[protected]`

Definition at line 199 of file OgrePatchSurface.h.

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

Definition at line 201 of file OgrePatchSurface.h.

HardwareVertexBufferSharedPtr Ogre::PatchSurface::mVertexBuffer`[protected]`

Definition at line 215 of file OgrePatchSurface.h.

HardwareIndexBufferSharedPtr Ogre::PatchSurface::mIndexBuffer`[protected]`

Definition at line 216 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mVertexOffset`[protected]`

Definition at line 217 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mIndexOffset`[protected]`

Definition at line 218 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mRequiredVertexCount`[protected]`

Definition at line 219 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mRequiredIndexCount`[protected]`

Definition at line 220 of file OgrePatchSurface.h.

size_t Ogre::PatchSurface::mCurrIndexCount`[protected]`

Definition at line 221 of file OgrePatchSurface.h.

AxisAlignedBox Ogre::PatchSurface::mAABB`[protected]`

Definition at line 223 of file OgrePatchSurface.h.

Real Ogre::PatchSurface::mBoundingSphere`[protected]`

Definition at line 224 of file OgrePatchSurface.h.

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

- OgrePatchSurface.h

Copyright © 2000-2005 by The OGRE Team
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Mon Jun 16 12:51:46 2008