64 lines
1.3 KiB
C++
64 lines
1.3 KiB
C++
/*
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* Copyright 2015 The Etc2Comp 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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*/
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#pragma once
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#include <math.h>
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namespace Etc
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{
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inline float LogToLinear(float a_fLog)
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{
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static const float ALPHA = 0.055f;
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static const float ONE_PLUS_ALPHA = 1.0f + ALPHA;
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if (a_fLog <= 0.04045f)
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{
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return a_fLog / 12.92f;
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}
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else
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{
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return powf((a_fLog + ALPHA) / ONE_PLUS_ALPHA, 2.4f);
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}
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}
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inline float LinearToLog(float &a_fLinear)
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{
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static const float ALPHA = 0.055f;
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static const float ONE_PLUS_ALPHA = 1.0f + ALPHA;
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if (a_fLinear <= 0.0031308f)
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{
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return 12.92f * a_fLinear;
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}
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else
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{
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return ONE_PLUS_ALPHA * powf(a_fLinear, (1.0f/2.4f)) - ALPHA;
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}
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}
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class ColorR8G8B8A8
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{
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public:
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unsigned char ucR;
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unsigned char ucG;
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unsigned char ucB;
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unsigned char ucA;
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};
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}
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