godot/thirdparty/etc2comp/EtcColor.h

65 lines
1.3 KiB
C++
Raw Normal View History

/*
* Copyright 2015 The Etc2Comp Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <math.h>
namespace Etc
{
inline float LogToLinear(float a_fLog)
{
static const float ALPHA = 0.055f;
static const float ONE_PLUS_ALPHA = 1.0f + ALPHA;
if (a_fLog <= 0.04045f)
{
return a_fLog / 12.92f;
}
else
{
return powf((a_fLog + ALPHA) / ONE_PLUS_ALPHA, 2.4f);
}
}
inline float LinearToLog(float &a_fLinear)
{
static const float ALPHA = 0.055f;
static const float ONE_PLUS_ALPHA = 1.0f + ALPHA;
if (a_fLinear <= 0.0031308f)
{
return 12.92f * a_fLinear;
}
else
{
return ONE_PLUS_ALPHA * powf(a_fLinear, (1.0f/2.4f)) - ALPHA;
}
}
class ColorR8G8B8A8
{
public:
unsigned char ucR;
unsigned char ucG;
unsigned char ucB;
unsigned char ucA;
};
}