1 files changed, 119 insertions, 0 deletions

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+#include "palette.h"
+#include <algorithm>
+
+const std::vector<Magick::ColorRGB> palette::reds = {
+  {"#ff4848"}, {"#ff7575"}, {"#ff8a8a"}, {"#ff9797"}, {"#ffa8a8"}, {"#ffbbbb"}
+};
+
+const std::vector<Magick::ColorRGB> palette::oranges = {
+  {"#ffbf85"}, {"#ffcfa4"}, {"#ffbd82"}, {"#ffc48e"}
+};
+
+const std::vector<Magick::ColorRGB> palette::yellows = {
+  {"#fdfda5"}, {"#eff0ac"}, {"#fef495"}
+};
+
+const std::vector<Magick::ColorRGB> palette::greens = {
+  {"#c6fcb4"}, {"#d4ffa2"}, {"#93eeaa"}
+};
+
+const std::vector<Magick::ColorRGB> palette::blues = {
+  {"#62d0ff"}, {"#62a9ff"}, {"#63e9fc"}, {"#7bcae1"}, {"#92fef9"}
+};
+
+const std::vector<Magick::ColorRGB> palette::purples = {
+  {"#dfb0fe"}, {"#b0a7f1"}, {"#ff86ff"}, {"#ffacec"}, {"#ff86c2"}, {"#ea8dfe"}
+};
+
+palette::palette(std::vector<Magick::Color> foci)
+{
+  if (foci.size() < 1)
+  {
+    throw std::invalid_argument("Must have at least one focus");
+  }
+
+  if (foci.size() < 2)
+  {
+    // Degenerate scenario, but deal with it gracefully.
+    foci.push_back(foci.front());
+  }
+
+  int sections = foci.size() - 1;
+  double sectionSize = 256.0 / static_cast<double>(sections);
+  for (int i=0; i<256; i++)
+  {
+    int section = std::floor(static_cast<double>(i) / sectionSize);
+    double interpolation = (static_cast<double>(i) / sectionSize) - section;
+
+    Magick::ColorHSL interpLeft = foci[section];
+    Magick::ColorHSL interpRight = foci[section+1];
+
+    double newHue;
+    double diff = interpRight.hue() - interpLeft.hue();
+    if (diff < 0)
+    {
+      std::swap(interpLeft, interpRight);
+      
+      diff = -diff;
+      interpolation = 1 - interpolation;
+    }
+    
+    if (diff > 0.5)
+    {
+      newHue = 1.0 + interpLeft.hue()
+        * (interpolation * (interpRight.hue() - interpLeft.hue() - 1.0));
+      
+      if (newHue > 1.0)
+      {
+        newHue -= 1.0;
+      }
+    } else {
+      newHue = interpLeft.hue() + interpolation * diff;
+    }
+    
+    Magick::ColorHSL interpolated(
+      newHue,
+      ((1.0 - interpolation) * interpLeft.saturation())
+        + (interpolation * interpRight.saturation()),
+      ((1.0 - interpolation) * interpLeft.luminosity())
+        + (interpolation * interpRight.luminosity()));
+
+    gradient_.push_back(interpolated);
+  }
+}
+
+palette palette::randomPalette(std::mt19937& rng)
+{
+  std::vector<Magick::Color> foci;
+  foci.push_back(reds[
+      std::uniform_int_distribution<int>(0, reds.size()-1)(rng)]);
+  foci.push_back(oranges[
+      std::uniform_int_distribution<int>(0, oranges.size()-1)(rng)]);
+  foci.push_back(yellows[
+      std::uniform_int_distribution<int>(0, yellows.size()-1)(rng)]);
+  foci.push_back(greens[
+      std::uniform_int_distribution<int>(0, greens.size()-1)(rng)]);
+  foci.push_back(blues[
+      std::uniform_int_distribution<int>(0, blues.size()-1)(rng)]);
+  foci.push_back(purples[
+      std::uniform_int_distribution<int>(0, purples.size()-1)(rng)]);
+
+  std::shuffle(std::begin(foci), std::end(foci), rng);
+
+  int origNum = foci.size();
+  int numOfFoci = std::uniform_int_distribution<int>(4, origNum)(rng);
+  for (int i=0; i<(origNum-numOfFoci); i++)
+  {
+    foci.pop_back();
+  }
+
+  foci.push_back(foci[0]);
+
+  return palette(std::move(foci));
+}
+
+Magick::Color palette::getColor(double shade) const
+{
+  int index = std::min((int)floor(shade * 256.0), 255);
+  return gradient_[index];
+}