From 5bba32429159b35c048e6b93e519c3bd4c1f4529 Mon Sep 17 00:00:00 2001
From: Alex Buis <alex@wearebuilders.io>
Date: Wed, 27 Dec 2017 14:23:26 +0100
Subject: [PATCH] #130 Fix color higher than 255 - fixed coding standards in
 color conversion tool. - added unit test for the 0..255 range fix.

---
 library/Phue/Helper/ColorConversion.php       | 19 ++++++++++++++-----
 .../Phue/Test/Helper/ColorConversionTest.php  |  7 +++++++
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/library/Phue/Helper/ColorConversion.php b/library/Phue/Helper/ColorConversion.php
index 4e0dde0..2e9c2c2 100644
--- a/library/Phue/Helper/ColorConversion.php
+++ b/library/Phue/Helper/ColorConversion.php
@@ -59,7 +59,7 @@ public static function convertRGBToXY($red, $green, $blue)
             'bri' => round($xyz['y'] * 255)
         );
     }
-
+    
     /**
      * Converts XY (and brightness) values to RGB
      *
@@ -76,12 +76,13 @@ public static function convertXYToRGB($x, $y, $bri = 255)
         $xyz['y'] = $bri / 255;
         $xyz['x'] = ($xyz['y'] / $y) * $x;
         $xyz['z'] = ($xyz['y'] / $y) * $z;
-
+        
         // Convert to RGB using Wide RGB D65 conversion
         $color['red'] = $xyz['x'] * 1.656492 - $xyz['y'] * 0.354851 - $xyz['z'] * 0.255038;
         $color['green'] = -$xyz['x'] * 0.707196 + $xyz['y'] * 1.655397 + $xyz['z'] * 0.036152;
         $color['blue'] = $xyz['x'] * 0.051713 - $xyz['y'] * 0.121364 + $xyz['z'] * 1.011530;
-
+        
+        $maxValue = 0;
         foreach ($color as $key => $normalized) {
             // Apply reverse gamma correction
             if ($normalized <= 0.0031308) {
@@ -89,11 +90,19 @@ public static function convertXYToRGB($x, $y, $bri = 255)
             } else {
                 $color[$key] = (1.0 + 0.055) * pow($normalized, 1.0 / 2.4) - 0.055;
             }
-
+            $color[$key] = max(0, $color[$key]);
+            if ($maxValue < $color[$key]) {
+                $maxValue = $color[$key];
+            }
+        }
+        foreach ($color as $key => $normalized) {
+            if ($maxValue > 1) {
+                $color[$key] /= $maxValue;
+            }
             // Scale back from a maximum of 1 to a maximum of 255
             $color[$key] = round($color[$key] * 255);
         }
-
+        
         return $color;
     }
 }
diff --git a/tests/Phue/Test/Helper/ColorConversionTest.php b/tests/Phue/Test/Helper/ColorConversionTest.php
index 31c1be2..64119a1 100644
--- a/tests/Phue/Test/Helper/ColorConversionTest.php
+++ b/tests/Phue/Test/Helper/ColorConversionTest.php
@@ -68,5 +68,12 @@ public function testConvertXYToRGB()
         $this->assertEquals($rgb['red'], 61);
         $this->assertEquals($rgb['green'], 178);
         $this->assertEquals($rgb['blue'], 112);
+        
+        // Test to make sure single RGB values falls within 0..255 range.
+        // old situation this was r -18, g 186, b -613.
+        $rgb = ColorConversion::convertXYToRGB(0.1979, 1.5005, 81);
+        $this->assertEquals($rgb['red'], 0);
+        $this->assertEquals($rgb['green'], 186);
+        $this->assertEquals($rgb['blue'], 0);
     }
 }