OpenSubdiv/opensubdiv/osd/ompKernel.cpp

127 lines
3.7 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.
//
#include "../osd/ompKernel.h"
#include "../osd/vertexDescriptor.h"
#include <cassert>
#include <cstdlib>
#include <omp.h>
#include <vector>
namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {
namespace Osd {
template <class T> T *
elementAtIndex(T * src, int index, VertexBufferDescriptor const &desc) {
return src + index * desc.stride;
}
static inline void
clear(float *dst, VertexBufferDescriptor const &desc) {
assert(dst);
memset(dst, 0, desc.length*sizeof(float));
}
static inline void
addWithWeight(float *dst, const float *src, int srcIndex, float weight,
VertexBufferDescriptor const &desc) {
assert(src and dst);
src = elementAtIndex(src, srcIndex, desc);
for (int k = 0; k < desc.length; ++k) {
dst[k] += src[k] * weight;
}
}
static inline void
copy(float *dst, int dstIndex, const float *src,
VertexBufferDescriptor const &desc) {
assert(src and dst);
dst = elementAtIndex(dst, dstIndex, desc);
memcpy(dst, src, desc.length*sizeof(float));
}
// XXXX manuelk this should be optimized further by using SIMD - considering
// OMP is somewhat obsolete - this is probably not worth it.
void
OmpEvalStencils(float const * src,
VertexBufferDescriptor const &srcDesc,
float * dst,
VertexBufferDescriptor const &dstDesc,
int const * sizes,
int const * offsets,
int const * indices,
float const * weights,
int start, int end) {
if (start > 0) {
sizes += start;
indices += offsets[start];
weights += offsets[start];
}
src += srcDesc.offset;
dst += dstDesc.offset;
int numThreads = omp_get_max_threads();
int n = end - start;
float * result = (float*)alloca(srcDesc.length * numThreads * sizeof(float));
#pragma omp parallel for
for (int i = 0; i < n; ++i) {
int index = i + (start > 0 ? start : 0); // Stencil index
// Get thread-local pointers
int const * threadIndices = indices + offsets[index];
float const * threadWeights = weights + offsets[index];
int threadId = omp_get_thread_num();
float * threadResult = result + threadId*srcDesc.length;
clear(threadResult, dstDesc);
for (int j=0; j<(int)sizes[index]; ++j) {
addWithWeight(threadResult, src,
threadIndices[j], threadWeights[j], srcDesc);
}
copy(dst, i, threadResult, dstDesc);
}
}
} // end namespace Osd
} // end namespace OPENSUBDIV_VERSION
} // end namespace OpenSubdiv