7c2d654d67
Chrome can't use Absl's CHECK because of collisions with its own version. PiperOrigin-RevId: 561740965
71 lines
2.2 KiB
C++
71 lines
2.2 KiB
C++
// Copyright 2019 The MediaPipe Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "mediapipe/examples/desktop/autoflip/quality/piecewise_linear_function.h"
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#include <stddef.h>
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#include <algorithm>
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#include <limits>
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#include <vector>
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#include "absl/log/absl_check.h"
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#include "mediapipe/framework/port/status.h"
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namespace mediapipe {
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namespace autoflip {
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void PiecewiseLinearFunction::AddPoint(double x, double y) {
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if (!points_.empty()) {
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ABSL_CHECK_GE(x, points_.back().x)
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<< "Points must be provided in non-decreasing x order.";
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}
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points_.push_back(PiecewiseLinearFunction::Point(x, y));
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}
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std::vector<PiecewiseLinearFunction::Point>::const_iterator
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PiecewiseLinearFunction::GetIntervalIterator(double input) const {
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PiecewiseLinearFunction::Point input_point(input, 0);
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std::vector<PiecewiseLinearFunction::Point>::const_iterator iter =
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std::lower_bound(points_.begin(), points_.end(), input_point,
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PointCompare());
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return iter;
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}
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double PiecewiseLinearFunction::Interpolate(
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const PiecewiseLinearFunction::Point& p1,
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const PiecewiseLinearFunction::Point& p2, double input) const {
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ABSL_CHECK_LT(p1.x, input);
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ABSL_CHECK_GE(p2.x, input);
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return p2.y - (p2.x - input) / (p2.x - p1.x) * (p2.y - p1.y);
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}
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double PiecewiseLinearFunction::Evaluate(double const input) const {
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std::vector<PiecewiseLinearFunction::Point>::const_iterator i =
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GetIntervalIterator(input);
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if (i == points_.begin()) {
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return points_.front().y;
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}
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if (i == points_.end()) {
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return points_.back().y;
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}
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std::vector<PiecewiseLinearFunction::Point>::const_iterator prev = i - 1;
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return Interpolate(*prev, *i, input);
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}
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} // namespace autoflip
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} // namespace mediapipe
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