OpenSubdiv/opensubdiv/far/stencilTable.h
2015-07-16 09:27:48 -07:00

435 lines
13 KiB
C++

//
// Copyright 2013 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
// names, trademarks, service marks, or product names of the Licensor
// and its affiliates, except as required to comply with Section 4(c) of
// the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#ifndef OPENSUBDIV3_FAR_STENCILTABLE_H
#define OPENSUBDIV3_FAR_STENCILTABLE_H
#include "../version.h"
#include "../far/types.h"
#include <cassert>
#include <cstring>
#include <vector>
#include <iostream>
namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {
namespace Far {
/// \brief Vertex stencil descriptor
///
/// Allows access and manipulation of a single stencil in a StencilTable.
///
class Stencil {
public:
/// \brief Default constructor
Stencil() {}
/// \brief Constructor
///
/// @param size Table pointer to the size of the stencil
///
/// @param indices Table pointer to the vertex indices of the stencil
///
/// @param weights Table pointer to the vertex weights of the stencil
///
Stencil(int * size,
Index * indices,
float * weights)
: _size(size),
_indices(indices),
_weights(weights) {
}
/// \brief Copy constructor
Stencil(Stencil const & other) {
_size = other._size;
_indices = other._indices;
_weights = other._weights;
}
/// \brief Returns the size of the stencil
int GetSize() const {
return *_size;
}
/// \brief Returns the size of the stencil as a pointer
int * GetSizePtr() const {
return _size;
}
/// \brief Returns the control vertices indices
Index const * GetVertexIndices() const {
return _indices;
}
/// \brief Returns the interpolation weights
float const * GetWeights() const {
return _weights;
}
/// \brief Advance to the next stencil in the table
void Next() {
int stride = *_size;
++_size;
_indices += stride;
_weights += stride;
}
protected:
friend class StencilTableFactory;
friend class LimitStencilTableFactory;
int * _size;
Index * _indices;
float * _weights;
};
/// \brief Table of subdivision stencils.
///
/// Stencils are the most direct methods of evaluation of locations on the limit
/// of a surface. Every point of a limit surface can be computed by linearly
/// blending a collection of coarse control vertices.
///
/// A stencil assigns a series of control vertex indices with a blending weight
/// that corresponds to a unique parametric location of the limit surface. When
/// the control vertices move in space, the limit location can be very efficiently
/// recomputed simply by applying the blending weights to the series of coarse
/// control vertices.
///
class StencilTable {
StencilTable(int numControlVerts,
std::vector<int> const& offsets,
std::vector<int> const& sizes,
std::vector<int> const& sources,
std::vector<float> const& weights,
bool includeCoarseVerts,
size_t firstOffset);
public:
virtual ~StencilTable() {};
/// \brief Returns the number of stencils in the table
int GetNumStencils() const {
return (int)_sizes.size();
}
/// \brief Returns the number of control vertices indexed in the table
int GetNumControlVertices() const {
return _numControlVertices;
}
/// \brief Returns a Stencil at index i in the table
Stencil GetStencil(Index i) const;
/// \brief Returns the number of control vertices of each stencil in the table
std::vector<int> const & GetSizes() const {
return _sizes;
}
/// \brief Returns the offset to a given stencil (factory may leave empty)
std::vector<Index> const & GetOffsets() const {
return _offsets;
}
/// \brief Returns the indices of the control vertices
std::vector<Index> const & GetControlIndices() const {
return _indices;
}
/// \brief Returns the stencil interpolation weights
std::vector<float> const & GetWeights() const {
return _weights;
}
/// \brief Returns the stencil at index i in the table
Stencil operator[] (Index index) const;
/// \brief Updates point values based on the control values
///
/// \note The destination buffers are assumed to have allocated at least
/// \c GetNumStencils() elements.
///
/// @param controlValues Buffer with primvar data for the control vertices
///
/// @param values Destination buffer for the interpolated primvar
/// data
///
/// @param start (skip to )index of first value to update
///
/// @param end Index of last value to update
///
template <class T>
void UpdateValues(T const *controlValues, T *values, Index start=-1, Index end=-1) const {
update(controlValues, values, _weights, start, end);
}
/// \brief Clears the stencils from the table
void Clear();
protected:
// Update values by applying cached stencil weights to new control values
template <class T> void update( T const *controlValues, T *values,
std::vector<float> const & valueWeights, Index start, Index end) const;
// Populate the offsets table from the stencil sizes in _sizes (factory helper)
void generateOffsets();
// Resize the table arrays (factory helper)
void resize(int nstencils, int nelems);
protected:
StencilTable() : _numControlVertices(0) {}
StencilTable(int numControlVerts)
: _numControlVertices(numControlVerts)
{ }
friend class StencilTableFactory;
// XXX: temporarily, GregoryBasis class will go away.
friend class GregoryBasis;
int _numControlVertices; // number of control vertices
std::vector<int> _sizes; // number of coeffiecient for each stencil
std::vector<Index> _offsets, // offset to the start of each stencil
_indices; // indices of contributing coarse vertices
std::vector<float> _weights; // stencil weight coefficients
};
/// \brief Limit point stencil descriptor
///
class LimitStencil : public Stencil {
public:
/// \brief Constructor
///
/// @param size Table pointer to the size of the stencil
///
/// @param indices Table pointer to the vertex indices of the stencil
///
/// @param weights Table pointer to the vertex weights of the stencil
///
/// @param duWeights Table pointer to the 'u' derivative weights
///
/// @param dvWeights Table pointer to the 'v' derivative weights
///
LimitStencil( int* size,
Index * indices,
float * weights,
float * duWeights,
float * dvWeights )
: Stencil(size, indices, weights),
_duWeights(duWeights),
_dvWeights(dvWeights) {
}
/// \brief
float const * GetDuWeights() const {
return _duWeights;
}
/// \brief
float const * GetDvWeights() const {
return _dvWeights;
}
/// \brief Advance to the next stencil in the table
void Next() {
int stride = *_size;
++_size;
_indices += stride;
_weights += stride;
_duWeights += stride;
_dvWeights += stride;
}
private:
friend class StencilTableFactory;
friend class LimitStencilTableFactory;
float * _duWeights, // pointer to stencil u derivative limit weights
* _dvWeights; // pointer to stencil v derivative limit weights
};
/// \brief Table of limit subdivision stencils.
///
///
class LimitStencilTable : public StencilTable {
LimitStencilTable(int numControlVerts,
std::vector<int> const& offsets,
std::vector<int> const& sizes,
std::vector<int> const& sources,
std::vector<float> const& weights,
std::vector<float> const& duWeights,
std::vector<float> const& dvWeights,
bool includeCoarseVerts,
size_t firstOffset);
public:
/// \brief Returns the 'u' derivative stencil interpolation weights
std::vector<float> const & GetDuWeights() const {
return _duWeights;
}
/// \brief Returns the 'v' derivative stencil interpolation weights
std::vector<float> const & GetDvWeights() const {
return _dvWeights;
}
/// \brief Updates derivative values based on the control values
///
/// \note The destination buffers ('uderivs' & 'vderivs') are assumed to
/// have allocated at least \c GetNumStencils() elements.
///
/// @param controlValues Buffer with primvar data for the control vertices
///
/// @param uderivs Destination buffer for the interpolated 'u'
/// derivative primvar data
///
/// @param vderivs Destination buffer for the interpolated 'v'
/// derivative primvar data
///
/// @param start (skip to )index of first value to update
///
/// @param end Index of last value to update
///
template <class T>
void UpdateDerivs(T const *controlValues, T *uderivs, T *vderivs,
int start=-1, int end=-1) const {
update(controlValues, uderivs, _duWeights, start, end);
update(controlValues, vderivs, _dvWeights, start, end);
}
/// \brief Clears the stencils from the table
void Clear();
private:
friend class LimitStencilTableFactory;
// Resize the table arrays (factory helper)
void resize(int nstencils, int nelems);
private:
std::vector<float> _duWeights, // u derivative limit stencil weights
_dvWeights; // v derivative limit stencil weights
};
// Update values by appling cached stencil weights to new control values
template <class T> void
StencilTable::update(T const *controlValues, T *values,
std::vector<float> const &valueWeights, Index start, Index end) const {
int const * sizes = &_sizes.at(0);
Index const * indices = &_indices.at(0);
float const * weights = &valueWeights.at(0);
if (start>0) {
assert(start<(Index)_offsets.size());
sizes += start;
indices += _offsets[start];
weights += _offsets[start];
values += start;
}
if (end<start or end<0) {
end = GetNumStencils();
}
int nstencils = end - std::max(0, start);
for (int i=0; i<nstencils; ++i, ++sizes) {
// Zero out the result accumulators
values[i].Clear();
// For each element in the array, add the coefs contribution
for (int j=0; j<*sizes; ++j, ++indices, ++weights) {
values[i].AddWithWeight( controlValues[*indices], *weights );
}
}
}
inline void
StencilTable::generateOffsets() {
Index offset=0;
int noffsets = (int)_sizes.size();
_offsets.resize(noffsets);
for (int i=0; i<(int)_sizes.size(); ++i ) {
_offsets[i]=offset;
offset+=_sizes[i];
}
}
inline void
StencilTable::resize(int nstencils, int nelems) {
_sizes.resize(nstencils);
_indices.resize(nelems);
_weights.resize(nelems);
}
// Returns a Stencil at index i in the table
inline Stencil
StencilTable::GetStencil(Index i) const {
assert((not _offsets.empty()) and i<(int)_offsets.size());
Index ofs = _offsets[i];
return Stencil( const_cast<int*>(&_sizes[i]),
const_cast<Index *>(&_indices[ofs]),
const_cast<float *>(&_weights[ofs]) );
}
inline Stencil
StencilTable::operator[] (Index index) const {
return GetStencil(index);
}
inline void
LimitStencilTable::resize(int nstencils, int nelems) {
StencilTable::resize(nstencils, nelems);
_duWeights.resize(nelems);
_dvWeights.resize(nelems);
}
} // end namespace Far
} // end namespace OPENSUBDIV_VERSION
using namespace OPENSUBDIV_VERSION;
} // end namespace OpenSubdiv
#endif // OPENSUBDIV3_FAR_STENCILTABLE_H