NEW: Ability to blend colors in templates

README.md

@@ -64,6 +64,7 @@ Here's a complete list of the `Color` methods available in templates:
  - `Blue` returns the blue color component
  - `CSSColor` returns the color as `rgba`. The alpha value can be specified with the (optional) argument.
  - `Luminance` the luminance of the color as a floating-point value ranging from 0-1
+ - `Blend` blends the color with a second background color (defaults to #FFFFFF) with the given opacity. `$BGColor.Blend(0.5, '#000000')` will give the color 50% opacity and put it on top of a black background.
  - `AlteredColorHSV` modifies the current color by the given HSV values. These values are offsets, so you could do something like this: `$BgColor.AlteredColorHSV(0.5, 0, 0)` which will return the color with the opposite hue. All parameters are percentage based and range from `0 - 1`. So doing: `$BgColor.AlteredColorHSV(0, 0, -0.2)` will result in a color with 20% less brightness (absolute, not relative).
 
 

code/Color.php

@@ -215,6 +215,31 @@ public function AlteredColorHSV($hChange, $sChange, $vChange){
 		return $color;
 	}
 
+	/**
+	 * Blend the color with a background color, with the given opacity level
+	 * @param float $opacity Opacity level of the current color (between 0 - 1)
+	 * @param string $background The background color
+	 * @return string
+	 */
+	public function Blend($opacity, $background = 'FFFFFF') {
+		list($R, $G, $B) = self::HEX_TO_RGB($this->value);
+		list($bgR, $bgG, $bgB) = self::HEX_TO_RGB(ltrim($background, '#'));
+		$opacity = self::clamp($opacity, 0, 1);
+
+		$add = array(
+			'r' => ($bgR - $R) / 100,
+			'g' => ($bgG - $G) / 100,
+			'b' => ($bgB - $B) / 100
+		);
+
+		$transparency = (1 - $opacity) * 100;
+		$R += intval($add['r'] * $transparency);
+		$G += intval($add['g'] * $transparency);
+		$B += intval($add['b'] * $transparency);
+
+		return self::RGB_TO_HEX($R, $G, $B);
+	}
+
 	private static function clamp($val, $min, $max){
 		return min($max, max($min, $val));
 	}