Function _FilterTimeDependentOutputs

pxr/exec/exec/program.cpp:717–757

}

static TfBits
_FilterTimeDependentOutputs(
    const VdfMaskedOutputVector &timeDependentInputNodeOutputs,
    const EfTime &oldTime,
    const EfTime &newTime)
{
    TRACE_FUNCTION();

    // One bitset per thread.
    const size_t numInputs = timeDependentInputNodeOutputs.size();
    tbb::enumerable_thread_specific<TfBits> threadBits([numInputs](){
        return TfBits(numInputs);
    });

    // For each time-dependent output, figure out if the computed value actually
    // changes between oldTime and newTime. If so, set the corresponding bit
    // in the bit set.
    WorkWithScopedParallelism(
        [&numInputs, &timeDependentInputNodeOutputs, &oldTime, &newTime,
            &threadBits](){
        WorkParallelForN(numInputs,[&](size_t b, size_t e){
            TfBits *const bits = &threadBits.local();
            for (size_t i = b; i != e; ++i) {
                const VdfNode &node =
                    timeDependentInputNodeOutputs[i].GetOutput()->GetNode();
                const Exec_AttributeInputNode *const inputNode =
                        dynamic_cast<const Exec_AttributeInputNode*>(&node);
                if (!inputNode || inputNode->IsTimeVarying(oldTime, newTime)) {
                    bits->Set(i);
                }
            }
        });
    });

    // Combine the thread-local bit sets into a single bit set and return it.
    TfBits result(numInputs);
    threadBits.combine_each([&result](const TfBits &bits){
        result |= bits;
    });
    return result;
}

PXR_NAMESPACE_CLOSE_SCOPE