Merge pull request #2 from willemstuursma/closest-color

Improve mechanism that picks the closest color
ricardofiorani · Oct 11, 2018 · 7a91c1a · 7a91c1a
2 parents 787e18e + d7adb4c
commit 7a91c1a
Showing 1 changed file with 14 additions and 12 deletions.
diff --git a/src/Pallete/ColorPalette.php b/src/Pallete/ColorPalette.php
@@ -6,7 +6,7 @@
 
 class ColorPalette implements LegoPaletteInterface
 {
-    private $palette = [
+    private const PALETTE = [
         '024' => [
             254,
             196,
@@ -264,28 +264,30 @@ class ColorPalette implements LegoPaletteInterface
         ],
     ];
 
+    /**
+     * @link https://stackoverflow.com/questions/4485229/rgb-to-closest-predefined-color
+     */
     public function pickClosestColor(AbstractColor $color): AbstractColor
     {
         $distances = [];
 
         $colorArray = $color->getArray();
 
-        foreach ($this->palette as $colorIdentifier => $colorSchema) {
-            $distance =
-                abs($colorSchema[0] - $colorArray[0]) +
-                abs($colorSchema[1] - $colorArray[1]) +
-                abs($colorSchema[2] - $colorArray[2]);
+        foreach (self::PALETTE as $colorIdentifier => $colorSchema) {
+            $rDistance = $colorSchema[0] - $colorArray[0];
+            $gDistance = $colorSchema[1] - $colorArray[1];
+            $bDistance = $colorSchema[2] - $colorArray[2];
 
-            $distances[$distance] = [$colorSchema[0], $colorSchema[1], $colorSchema[2]];
-        }
+            $distance = ($rDistance * .299) ** 2 + ($gDistance * .587) ** 2 + ($bDistance * .114) ** 2;
 
-        ksort($distances);
+            $distances[$colorIdentifier] = $distance;
+        }
 
-        $colorFound = reset($distances);
+        asort($distances);
 
-        list($r, $g, $b) = $colorFound;
+        $colorIdentifier = array_keys($distances)[0];
 
-        $color->initFromRgb($r, $g, $b);
+        $color->initFromRgb(...self::PALETTE[$colorIdentifier]);
 
         return $color;
     }