//---------------------------------------------------------------------------
/*
Rainbow, class for a rainbow color gradient
Copyright (C) 2011 Richel Bilderbeek
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
//From http://www.richelbilderbeek.nl/CppRainbow.htm
//---------------------------------------------------------------------------
#include <cassert>
#include <cmath>
//---------------------------------------------------------------------------
#include "rainbow.h"
//---------------------------------------------------------------------------
void Rainbow::GetRgb(
const double x,
double& r,
double& g,
double& b)
{
assert(x >= 0.0);
assert(x <= 1.0);
const double f_r = std::max(0.0,
(x < 0.5
? std::cos(x * 1.5 * M_PI)
: -std::sin(x * 1.5 * M_PI)
) );
const double f_g = std::max(0.0, std::sin( x * 1.5 * M_PI ) );
const double f_b = std::max(0.0, -std::cos( x * 1.5 * M_PI ) );
const double max = std::max(f_r, std::max(f_g,f_b));
assert(max!=0);
r = f_r / max;
g = f_g / max;
b = f_b / max;
}
//---------------------------------------------------------------------------
const std::string Rainbow::GetVersion()
{
return "1.0";
}
//---------------------------------------------------------------------------
const std::vector<std::string> Rainbow::GetVersionHistory()
{
std::vector<std::string> v;
v.push_back("2011-08-31: Version 1.0: initial version");
return v;
}
//---------------------------------------------------------------------------
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