1 files changed, 81 insertions, 0 deletions
diff --git a/app/ColorGenerator.php b/app/ColorGenerator.php
new file mode 100644
index 0000000000..89c4ef6425
--- /dev/null
+++ b/app/ColorGenerator.php
@@ -0,0 +1,81 @@
+<?php
+namespace Fisharebest\Webtrees;
+
+	/**
+	 * webtrees: online genealogy
+	 * Copyright (C) 2015 webtrees development team
+	 * 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/>.
+	 */
+
+/**
+ * Class colorGenerator
+ */
+class ColorGenerator {
+
+	private $hue;
+	private $basehue;
+	private $saturation;
+	private $lightness;
+	private $baselightness;
+	private $alpha;
+	private $range;
+
+	/**
+	 * @param integer $hue (0Deg = Red, 120Deg = green, 240Deg = blue)
+	 * @param integer $saturation
+	 * @param integer $lightness
+	 * @param integer $alpha
+	 * @param integer $range (sign determines direction. positive = clockwise, negative = anticlockwise)
+	 */
+	public function __construct($hue, $saturation, $lightness, $alpha, $range) {
+		$this->hue           = $hue;
+		$this->basehue       = $hue;
+		$this->saturation    = $saturation;
+		$this->lightness     = $lightness;
+		$this->baselightness = $lightness;
+		$this->alpha         = $alpha;
+		$this->range         = $range;
+	}
+
+	/**
+	 * Function getNextColor
+	 *
+	 * $lightness cycles between $baselightness and 100% in $lightnessStep steps
+	 * $hue cycles on each complete $lightness cycle
+	 * between $basehue and $basehue + $range degrees in $hueStep degrees
+	 *
+	 * @param int $lightnessStep
+	 * @param int $hueStep
+	 * @return string
+	 */
+	public function getNextColor($lightnessStep = 10, $hueStep = 15) {
+		$lightness = $this->lightness + $lightnessStep;
+		$hue       = $this->hue;
+
+		if ($lightness >= 100) {
+			$lightness = $this->baselightness;
+			$hue += $hueStep * (abs($this->range) / $this->range);
+			if (($hue - $this->basehue) * ($hue - ($this->basehue + $this->range)) >= 0) {
+				$hue = $this->basehue;
+			}
+			$this->hue = $hue;
+		}
+		$this->lightness = $lightness;
+
+		return sprintf("hsla(%s, %s%%, %s%%, %s)",
+			$this->hue,
+			$this->saturation,
+			$this->lightness,
+			$this->alpha);
+	}
+
+}