From ad2a7ddd1642bedaa97915fcbd5d3a52fb809ece Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Torsten=20L=C3=BCcke?= <privat@torsten-hettstedt.de>
Date: Thu, 18 Mar 2021 08:34:54 +0100
Subject: [PATCH] Die Umwandlung von HSV zu CMYK ist erfolgreich.

---
 ...eSaturationValueToCyanMagentaYellowKey.php | 92 +++++++++----------
 1 file changed, 44 insertions(+), 48 deletions(-)

diff --git a/src/Transformer/Utilities/HueSaturationValueToCyanMagentaYellowKey.php b/src/Transformer/Utilities/HueSaturationValueToCyanMagentaYellowKey.php
index eb9bac5..6913fd7 100644
--- a/src/Transformer/Utilities/HueSaturationValueToCyanMagentaYellowKey.php
+++ b/src/Transformer/Utilities/HueSaturationValueToCyanMagentaYellowKey.php
@@ -10,11 +10,13 @@ use TorstenHettstedt\Colors\ColorModels\HueSaturationValue;
 class HueSaturationValueToCyanMagentaYellowKey
 {
     /** @var int : Größe des Intervals in 1/100 Grad */
-    protected const INTERVAL = 60 * 100;
+    protected const INTERVAL = 60.0 * 100.0;
 
     // Daten für HSV
     /** @var float : Definition des Farbton als Anteil eines Vollkreises '$Hue * π' */
     protected float $hue;
+    /** @var float : Anteil am Vollkreis in 1/100 Grad  */
+    protected float $hueAsPercentGrad;
     /** @var float : Definition der Sättigung der Farbe */
     protected float $saturation;
     /** @var float : Definition der Helligkeit der Farbe */
@@ -38,6 +40,7 @@ class HueSaturationValueToCyanMagentaYellowKey
     public function __construct(HueSaturationValue $from_color)
     {
         $this->hue = $from_color->getHue();
+        $this->hueAsPercentGrad = intval($this->hue * self::INTERVAL * 6);
         $this->saturation = $from_color->getSaturation();
         $this->value = $from_color->getValue();
     }
@@ -56,59 +59,52 @@ class HueSaturationValueToCyanMagentaYellowKey
 
     protected function processConvert(): void
     {
-        if ($this->saturation === 0.0) {
-            $this->key = $this->value;
-        } else {
+        $this->key = 1 - $this->value;
+        if ($this->saturation !== 0.0) {
             $this->splitColor();
         }
     }
 
     protected function splitColor(): void
     {
-//        // Anteil am Vollkreis in 1/100 Grad
-//        $percent_grad = intval($this->hue * 360 * 100);
-//        // ID des zu nutzenden Interval
-//        $interval_id = intdiv($percent_grad , self::INTERVAL);
-//        // Rest-Anteil am Vollkreis des aktuellen Intervals als Wert '[0,1]'
-//        $remainder = (($percent_grad % self::INTERVAL) / self::INTERVAL);
-//        $help_values = [
-//            $this->value,
-//            $this->value * ( 1 - $this->saturation),
-//            $this->value * ( 1 - $this->saturation * $remainder),
-//            $this->value * ( 1 - $this->saturation * (1 - $remainder)),
-//        ];
-//        switch ($interval_id) {
-//            case 1:
-//                $this->red = $help_values[2];
-//                $this->green = $help_values[0];
-//                $this->blu = $help_values[1];
-//                break;
-//            case 2:
-//                $this->red = $help_values[1];
-//                $this->green = $help_values[0];
-//                $this->blu = $help_values[3];
-//                break;
-//            case 3:
-//                $this->red = $help_values[1];
-//                $this->green = $help_values[2];
-//                $this->blu = $help_values[0];
-//                break;
-//            case 4:
-//                $this->red = $help_values[3];
-//                $this->green = $help_values[1];
-//                $this->blu = $help_values[0];
-//                break;
-//            case 5:
-//                $this->red = $help_values[0];
-//                $this->green = $help_values[1];
-//                $this->blu = $help_values[2];
-//                break;
-//            default:
-//                $this->red = $help_values[0];
-//                $this->green = $help_values[3];
-//                $this->blu = $help_values[1];
-//                break;
-//        }
+        // ID des zu nutzenden Interval
+        $interval_id = intdiv($this->hueAsPercentGrad , self::INTERVAL);
+
+        switch ($interval_id) {
+            case 1: // Yellow
+                $this->cyan = $this->calcRemainder();
+                $this->yellow = $this->saturation;
+                break;
+            case 2:
+                $this->cyan = $this->saturation;
+                $this->yellow = $this->calcRemainder(true);
+                break;
+            case 3: // Cyan
+                $this->cyan = $this->saturation;
+                $this->magenta = $this->calcRemainder();
+                break;
+            case 4:
+                $this->cyan = $this->calcRemainder(true);
+                $this->magenta = $this->saturation;
+                break;
+            case 5: // Magenta
+                $this->magenta = $this->saturation;
+                $this->yellow = $this->calcRemainder();
+                break;
+            default:
+                $this->magenta = $this->calcRemainder(true);
+                $this->yellow = $this->saturation;
+                break;
+        }
+    }
+
+    protected function calcRemainder($reciprocal = false): float
+    {
+        // Rest-Anteil am Vollkreis des aktuellen Intervals als Wert '[0,1]'
+        $remainder_grad = $this->hueAsPercentGrad % self::INTERVAL;
+        // Rest-Anteil am Vollkreis des aktuellen Intervals als Wert '[0,1]'
+        $remainder = $remainder_grad / self::INTERVAL;
+        return $this->saturation * ($reciprocal ? (1 - $remainder) : $remainder);
     }
 
 }
\ No newline at end of file