e12c08e8d1
Apply clang format as proposed in T53211. For details on usage and instructions for migrating branches without conflicts, see: https://wiki.blender.org/wiki/Tools/ClangFormat
71 lines
2.1 KiB
C++
71 lines
2.1 KiB
C++
/*
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* Copyright 2011-2015 Blender Foundation
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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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*/
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#include "util/util_math_cdf.h"
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#include "util/util_algorithm.h"
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#include "util/util_math.h"
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CCL_NAMESPACE_BEGIN
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/* Invert pre-calculated CDF function. */
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void util_cdf_invert(const int resolution,
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const float from,
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const float to,
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const vector<float> &cdf,
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const bool make_symmetric,
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vector<float> &inv_cdf)
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{
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const float inv_resolution = 1.0f / (float)resolution;
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const float range = to - from;
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inv_cdf.resize(resolution);
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if (make_symmetric) {
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const int half_size = (resolution - 1) / 2;
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for (int i = 0; i <= half_size; i++) {
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float x = i / (float)half_size;
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int index = upper_bound(cdf.begin(), cdf.end(), x) - cdf.begin();
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float t;
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if (index < cdf.size() - 1) {
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t = (x - cdf[index]) / (cdf[index + 1] - cdf[index]);
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}
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else {
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t = 0.0f;
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index = cdf.size() - 1;
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}
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float y = ((index + t) / (resolution - 1)) * (2.0f * range);
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inv_cdf[half_size + i] = 0.5f * (1.0f + y);
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inv_cdf[half_size - i] = 0.5f * (1.0f - y);
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}
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}
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else {
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for (int i = 0; i < resolution; i++) {
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float x = from + range * (float)i * inv_resolution;
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int index = upper_bound(cdf.begin(), cdf.end(), x) - cdf.begin();
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float t;
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if (index < cdf.size() - 1) {
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t = (x - cdf[index]) / (cdf[index + 1] - cdf[index]);
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}
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else {
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t = 0.0f;
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index = resolution;
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}
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inv_cdf[i] = (index + t) * inv_resolution;
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}
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}
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}
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CCL_NAMESPACE_END
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