Rename some variables to improve legibility

Author: ksubileau

lib/ColorThief/ColorThief.php

@@ -262,8 +262,8 @@ private static function vboxFromHistogram(array $histo)
         $rgbMax = [-PHP_INT_MAX, -PHP_INT_MAX, -PHP_INT_MAX];
 
         // find min/max
-        foreach ($histo as $index => $count) {
-            $rgb = static::getColorsFromIndex($index, self::SIGBITS);
+        foreach ($histo as $bucketIndex => $count) {
+            $rgb = static::getColorsFromIndex($bucketIndex, self::SIGBITS);
 
             // For each color components
             for ($i = 0; $i < 3; $i++) {
@@ -285,7 +285,7 @@ private static function vboxFromHistogram(array $histo)
      * @param array  $partialSum
      * @param int    $total
      *
-     * @return array
+     * @return array|void
      */
     private static function doCut($color, $vBox, $partialSum, $total)
     {

lib/ColorThief/VBox.php

@@ -110,6 +110,8 @@ public function avg($force = false)
                             ColorThief::SIGBITS
                         );
 
+                        // The bucket values need to be multiplied by $mult to get the RGB values.
+                        // Can't use a left shift here, as we're working with a floating point number to put the value at the bucket's midpoint.
                         $hval = isset($this->histo[$bucketIndex]) ? $this->histo[$bucketIndex] : 0;
                         $ntot += $hval;
                         $rsum += ($hval * ($redBucket + 0.5) * $mult);
@@ -143,19 +145,20 @@ public function avg($force = false)
         return $this->avg;
     }
 
-    public function contains(array $pixel, $rshift = ColorThief::RSHIFT)
+    public function contains(array $rgbValue, $rshift = ColorThief::RSHIFT)
     {
-        $rval = $pixel[0] >> $rshift;
-        $gval = $pixel[1] >> $rshift;
-        $bval = $pixel[2] >> $rshift;
+        // Get the buckets from the RGB values.
+        $redBucket = $rgbValue[0] >> $rshift;
+        $greenBucket = $rgbValue[1] >> $rshift;
+        $blueBucket = $rgbValue[2] >> $rshift;
 
         return
-            $rval >= $this->r1 &&
-            $rval <= $this->r2 &&
-            $gval >= $this->g1 &&
-            $gval <= $this->g2 &&
-            $bval >= $this->b1 &&
-            $bval <= $this->b2;
+            $redBucket >= $this->r1 &&
+            $redBucket <= $this->r2 &&
+            $greenBucket >= $this->g1 &&
+            $greenBucket <= $this->g2 &&
+            $blueBucket >= $this->b1 &&
+            $blueBucket <= $this->b2;
     }
 
     /**