Color.cpp

/*
 Copyright (C) 2010-2017 Kristian Duske

 This file is part of TrenchBroom.

 TrenchBroom 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.

 TrenchBroom 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 TrenchBroom. If not, see <http://www.gnu.org/licenses/>.
 */

#include "Color.h"

#include <vecmath/scalar.h>
#include <vecmath/vec.h>
#include <vecmath/vec_io.h>

#include <sstream>

namespace TrenchBroom {
std::optional<Color> Color::parse(const std::string& str) {
  if (const auto c4 = vm::parse<float, 4>(str)) {
    return Color(c4->x(), c4->y(), c4->z(), c4->w());
  } else if (const auto c3 = vm::parse<float, 3>(str)) {
    return Color(c3->x(), c3->y(), c3->z());
  } else {
    return std::nullopt;
  }
}

std::string Color::toString() const {
  std::stringstream ss;
  if (a() == 1.0f) {
    ss << this->xyz();
  } else {
    ss << this;
  }
  return ss.str();
}

Color::Color()
  : vec<float, 4>(0.0f, 0.0f, 0.0f, 0.0f) {}

Color::Color(const vec<float, 4>& i_v)
  : vec<float, 4>(i_v) {}

Color::Color(const float r, const float g, const float b, const float a)
  : vec<float, 4>(r, g, b, a) {}

Color::Color(const Color& color, const float a)
  : vec<float, 4>(color.r(), color.g(), color.b(), a) {}

Color::Color(
  const unsigned char r, const unsigned char g, const unsigned char b, const unsigned char a)
  : vec<float, 4>(
      static_cast<float>(r) / 255.0f, static_cast<float>(g) / 255.0f,
      static_cast<float>(b) / 255.0f, static_cast<float>(a) / 255.0f) {}

Color::Color(const int r, const int g, const int b, const int a)
  : vec<float, 4>(
      static_cast<float>(r) / 255.0f, static_cast<float>(g) / 255.0f,
      static_cast<float>(b) / 255.0f, static_cast<float>(a) / 255.0f) {}

Color::Color(const int r, const int g, const int b, const float a)
  : vec<float, 4>(
      static_cast<float>(r) / 255.0f, static_cast<float>(g) / 255.0f,
      static_cast<float>(b) / 255.0f, a) {}

float Color::r() const {
  return x();
}

float Color::g() const {
  return y();
}

float Color::b() const {
  return z();
}

float Color::a() const {
  return w();
}

void Color::rgbToHSB(const float r, const float g, const float b, float& h, float& s, float& br) {
  assert(r >= 0.0f && r <= 1.0f);
  assert(g >= 0.0f && g <= 1.0f);
  assert(b >= 0.0f && b <= 1.0f);

  const float max = vm::max(r, g, b);
  const float min = vm::min(r, g, b);
  const float dist = max - min;

  br = max;
  if (br != 0.0f)
    s = dist / max;
  else
    s = 0.0f;

  if (s == 0.0f) {
    h = 0.0f;
  } else {
    const float rc = (max - r) / dist;
    const float gc = (max - g) / dist;
    const float bc = (max - b) / dist;
    if (r == max)
      h = bc - gc;
    else if (g == max)
      h = 2.0f + rc - bc;
    else
      h = 4.0f + gc - rc;
    h = h / 6.0f;
    if (h < 0)
      h = h + 1.0f;
  }
}
} // namespace TrenchBroom