Add contrastRatio method

spatie · Apr 12, 2021 · 6a24b0d · 6a24b0d
1 parent 1da100f
commit 6a24b0d
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Showing 6 changed files with 82 additions and 0 deletions.
diff --git a/src/Color.php b/src/Color.php
@@ -14,6 +14,8 @@ public function blue();
 
     public function luminance(): float;
 
+    public function contrastRatio(): float;
+
     public function toHex(): Hex;
 
     public function toHsl(): Hsl;

diff --git a/src/Hex.php b/src/Hex.php
@@ -50,6 +50,22 @@ public function luminance(): float
         return Convert::rgbValueToLuminance($rgb->red(), $rgb->green(), $rgb->blue());
     }
 
+    public function contrastRatio(): float
+    {
+        $luminance = $this->luminance();
+        $black = new Rgb(0, 0, 0);
+        $blackLuminance = $black->luminance();
+
+        $contrastRatio = 0;
+        if ($luminance > $blackLuminance) {
+            $contrastRatio = (int) (($luminance + 0.05) / ($blackLuminance + 0.05));
+        } else {
+            $contrastRatio = (int) (($blackLuminance + 0.05) / ($luminance + 0.05));
+        }
+
+        return $contrastRatio;
+    }
+
     public function toHex(): self
     {
         return new self($this->red, $this->green, $this->blue);

diff --git a/src/Hsl.php b/src/Hsl.php
@@ -65,6 +65,22 @@ public function luminance(): float
         return Convert::rgbValueToLuminance($rgb->red(), $rgb->green(), $rgb->blue());
     }
 
+    public function contrastRatio(): float
+    {
+        $luminance = $this->luminance();
+        $black = new Rgb(0, 0, 0);
+        $blackLuminance = $black->luminance();
+
+        $contrastRatio = 0;
+        if ($luminance > $blackLuminance) {
+            $contrastRatio = (int) (($luminance + 0.05) / ($blackLuminance + 0.05));
+        } else {
+            $contrastRatio = (int) (($blackLuminance + 0.05) / ($luminance + 0.05));
+        }
+
+        return $contrastRatio;
+    }
+
     public function toHex(): Hex
     {
         return new Hex(

diff --git a/src/Hsla.php b/src/Hsla.php
@@ -73,6 +73,22 @@ public function luminance(): float
         return Convert::rgbValueToLuminance($rgb->red(), $rgb->green(), $rgb->blue());
     }
 
+    public function contrastRatio(): float
+    {
+        $luminance = $this->luminance();
+        $black = new Rgb(0, 0, 0);
+        $blackLuminance = $black->luminance();
+
+        $contrastRatio = 0;
+        if ($luminance > $blackLuminance) {
+            $contrastRatio = (int) (($luminance + 0.05) / ($blackLuminance + 0.05));
+        } else {
+            $contrastRatio = (int) (($blackLuminance + 0.05) / ($luminance + 0.05));
+        }
+
+        return $contrastRatio;
+    }
+
     public function toHex(): Hex
     {
         return new Hex(

diff --git a/src/Rgb.php b/src/Rgb.php
@@ -53,6 +53,22 @@ public function luminance(): float
         return Convert::rgbValueToLuminance($this->red, $this->green, $this->blue);
     }
 
+    public function contrastRatio(): float
+    {
+        $luminance = $this->luminance();
+        $black = new self(0, 0, 0);
+        $blackLuminance = $black->luminance();
+
+        $contrastRatio = 0;
+        if ($luminance > $blackLuminance) {
+            $contrastRatio = (int) (($luminance + 0.05) / ($blackLuminance + 0.05));
+        } else {
+            $contrastRatio = (int) (($blackLuminance + 0.05) / ($luminance + 0.05));
+        }
+
+        return $contrastRatio;
+    }
+
     public function toHex(): Hex
     {
         return new Hex(

diff --git a/src/Rgba.php b/src/Rgba.php
@@ -63,6 +63,22 @@ public function luminance(): float
         return Convert::rgbValueToLuminance($this->red, $this->green, $this->blue);
     }
 
+    public function contrastRatio(): float
+    {
+        $luminance = $this->luminance();
+        $black = new self(0, 0, 0);
+        $blackLuminance = $black->luminance();
+
+        $contrastRatio = 0;
+        if ($luminance > $blackLuminance) {
+            $contrastRatio = (int) (($luminance + 0.05) / ($blackLuminance + 0.05));
+        } else {
+            $contrastRatio = (int) (($blackLuminance + 0.05) / ($luminance + 0.05));
+        }
+
+        return $contrastRatio;
+    }
+
     public function toHex(): Hex
     {
         return $this->toRgb()->toHex();