Jacques Lucke
ab444a80a2
This refactor had two main goals: * Simplify the sampling code by using an algorithm with fewer special cases. * Generalize the sampling to support non-sorted samples. The `SampleSegmentHint` optimization was inspired by `ValueAccessor` from OpenVDB and improves performance 2x in my test cases. Differential Revision: https://developer.blender.org/D15348
59 lines
2.0 KiB
C++
59 lines
2.0 KiB
C++
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#include "BLI_length_parameterize.hh"
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#include "BLI_task.hh"
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namespace blender::length_parameterize {
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void sample_uniform(const Span<float> lengths,
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const bool include_last_point,
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MutableSpan<int> r_segment_indices,
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MutableSpan<float> r_factors)
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{
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const int count = r_segment_indices.size();
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BLI_assert(count > 0);
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BLI_assert(lengths.size() >= 1);
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BLI_assert(std::is_sorted(lengths.begin(), lengths.end()));
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if (count == 1) {
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r_segment_indices[0] = 0;
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r_factors[0] = 0.0f;
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return;
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}
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const float total_length = lengths.last();
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const float step_length = total_length / (count - include_last_point);
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threading::parallel_for(IndexRange(count), 512, [&](const IndexRange range) {
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SampleSegmentHint hint;
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for (const int i : range) {
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/* Use minimum to avoid issues with floating point accuracy. */
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const float sample_length = std::min(total_length, i * step_length);
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sample_at_length(lengths, sample_length, r_segment_indices[i], r_factors[i], &hint);
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}
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});
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}
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void sample_at_lengths(const Span<float> accumulated_segment_lengths,
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const Span<float> sample_lengths,
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MutableSpan<int> r_segment_indices,
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MutableSpan<float> r_factors)
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{
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BLI_assert(
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std::is_sorted(accumulated_segment_lengths.begin(), accumulated_segment_lengths.end()));
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BLI_assert(std::is_sorted(sample_lengths.begin(), sample_lengths.end()));
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const int count = sample_lengths.size();
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BLI_assert(count == r_segment_indices.size());
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BLI_assert(count == r_factors.size());
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threading::parallel_for(IndexRange(count), 512, [&](const IndexRange range) {
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SampleSegmentHint hint;
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for (const int i : range) {
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const float sample_length = sample_lengths[i];
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sample_at_length(
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accumulated_segment_lengths, sample_length, r_segment_indices[i], r_factors[i], &hint);
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}
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});
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}
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} // namespace blender::length_parameterize
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