From e72b0ff6df6e596c41eb3f71f31a85f13c904082 Mon Sep 17 00:00:00 2001
From: Oliver Vogel <oliver@olivervogel.com>
Date: Mon, 9 Oct 2023 16:30:03 +0200
Subject: [PATCH] Refactor color management

---
 src/Colors/Cmyk/Channels/Cyan.php        |  45 +++++++++
 src/Colors/Cmyk/Channels/Key.php         |   8 ++
 src/Colors/Cmyk/Channels/Magenta.php     |   8 ++
 src/Colors/Cmyk/Channels/Yellow.php      |   8 ++
 src/Colors/Cmyk/Color.php                |  97 +++++++++++++++++++
 src/Colors/Cmyk/Colorspace.php           |  33 +++++++
 src/Colors/Rgb/Channels/Blue.php         |   8 ++
 src/Colors/Rgb/Channels/Green.php        |   8 ++
 src/Colors/Rgb/Channels/Red.php          |  45 +++++++++
 src/Colors/Rgb/Color.php                 | 115 +++++++++++++++++++++++
 src/Colors/Rgb/Colorspace.php            |  27 ++++++
 src/Exceptions/ColorException.php        |   8 ++
 src/Interfaces/ColorChannelInterface.php |  12 +++
 src/Interfaces/ColorInterface.php        |  20 ++--
 src/Interfaces/ColorspaceInterface.php   |   8 ++
 tests/Colors/Rgb/ColorTest.php           | 106 +++++++++++++++++++++
 16 files changed, 548 insertions(+), 8 deletions(-)
 create mode 100644 src/Colors/Cmyk/Channels/Cyan.php
 create mode 100644 src/Colors/Cmyk/Channels/Key.php
 create mode 100644 src/Colors/Cmyk/Channels/Magenta.php
 create mode 100644 src/Colors/Cmyk/Channels/Yellow.php
 create mode 100644 src/Colors/Cmyk/Color.php
 create mode 100644 src/Colors/Cmyk/Colorspace.php
 create mode 100644 src/Colors/Rgb/Channels/Blue.php
 create mode 100644 src/Colors/Rgb/Channels/Green.php
 create mode 100644 src/Colors/Rgb/Channels/Red.php
 create mode 100644 src/Colors/Rgb/Color.php
 create mode 100644 src/Colors/Rgb/Colorspace.php
 create mode 100644 src/Exceptions/ColorException.php
 create mode 100644 src/Interfaces/ColorChannelInterface.php
 create mode 100644 src/Interfaces/ColorspaceInterface.php
 create mode 100644 tests/Colors/Rgb/ColorTest.php

diff --git a/src/Colors/Cmyk/Channels/Cyan.php b/src/Colors/Cmyk/Channels/Cyan.php
new file mode 100644
index 00000000..cb40daac
--- /dev/null
+++ b/src/Colors/Cmyk/Channels/Cyan.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Intervention\Image\Colors\Cmyk\Channels;
+
+use Intervention\Image\Exceptions\ColorException;
+use Intervention\Image\Interfaces\ColorChannelInterface;
+
+class Cyan implements ColorChannelInterface
+{
+    protected int $value;
+
+    public function __construct(int $value)
+    {
+        $this->value = $this->validate($value);
+    }
+
+    public function value(): int
+    {
+        return $this->value;
+    }
+
+    public function normalize($precision = 32): float
+    {
+        return round($this->value() / $this->max(), $precision);
+    }
+
+    public function min(): int
+    {
+        return 0;
+    }
+
+    public function max(): int
+    {
+        return 100;
+    }
+
+    public function validate(mixed $value): mixed
+    {
+        if ($value < $this->min() || $value > $this->max()) {
+            throw new ColorException('CMYK color values must be in range 0-100.');
+        }
+
+        return $value;
+    }
+}
diff --git a/src/Colors/Cmyk/Channels/Key.php b/src/Colors/Cmyk/Channels/Key.php
new file mode 100644
index 00000000..2893d2af
--- /dev/null
+++ b/src/Colors/Cmyk/Channels/Key.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Colors\Cmyk\Channels;
+
+class Key extends Cyan
+{
+    //
+}
diff --git a/src/Colors/Cmyk/Channels/Magenta.php b/src/Colors/Cmyk/Channels/Magenta.php
new file mode 100644
index 00000000..7c255e8f
--- /dev/null
+++ b/src/Colors/Cmyk/Channels/Magenta.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Colors\Cmyk\Channels;
+
+class Magenta extends Cyan
+{
+    //
+}
diff --git a/src/Colors/Cmyk/Channels/Yellow.php b/src/Colors/Cmyk/Channels/Yellow.php
new file mode 100644
index 00000000..7446e522
--- /dev/null
+++ b/src/Colors/Cmyk/Channels/Yellow.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Colors\Cmyk\Channels;
+
+class Yellow extends Cyan
+{
+    //
+}
diff --git a/src/Colors/Cmyk/Color.php b/src/Colors/Cmyk/Color.php
new file mode 100644
index 00000000..63b90b6d
--- /dev/null
+++ b/src/Colors/Cmyk/Color.php
@@ -0,0 +1,97 @@
+<?php
+
+namespace Intervention\Image\Colors\Cmyk;
+
+use Intervention\Image\Colors\Cmyk\Channels\Cyan;
+use Intervention\Image\Colors\Cmyk\Channels\Magenta;
+use Intervention\Image\Colors\Cmyk\Channels\Yellow;
+use Intervention\Image\Colors\Cmyk\Channels\Key;
+use Intervention\Image\Colors\Cmyk\Colorspace as CmykColorspace;
+use Intervention\Image\Colors\Rgb\Color as RgbColor;
+use Intervention\Image\Colors\Rgb\Colorspace as RgbColorspace;
+use Intervention\Image\Interfaces\ColorInterface;
+use Intervention\Image\Interfaces\ColorspaceInterface;
+
+class Color implements ColorInterface
+{
+    protected array $channels;
+
+    protected Cyan $cyan;
+    protected Magenta $magenta;
+    protected Yellow $yellow;
+    protected Key $key;
+
+    public function __construct(int $c, int $m, int $y, int $k)
+    {
+        $this->cyan = new Cyan($c);
+        $this->magenta = new Magenta($m);
+        $this->yellow = new Yellow($y);
+        $this->key = new Key($k);
+    }
+
+    public function channels(): array
+    {
+        return $this->channels;
+    }
+
+    public function cyan(): Cyan
+    {
+        return $this->cyan;
+    }
+
+    public function magenta(): Magenta
+    {
+        return $this->magenta;
+    }
+
+    public function yellow(): Yellow
+    {
+        return $this->yellow;
+    }
+
+    public function key(): Key
+    {
+        return $this->key;
+    }
+
+    public function toArray(): array
+    {
+        return [
+            $this->cyan()->value(),
+            $this->magenta()->value(),
+            $this->yellow()->value(),
+            $this->key()->value(),
+        ];
+    }
+
+    public function transformTo(string|ColorspaceInterface $colorspace): ColorInterface
+    {
+        $colorspace = match (true) {
+            is_object($colorspace) => $colorspace,
+            default => new $colorspace(),
+        };
+
+        return $colorspace->transformColor($this);
+    }
+
+    public function toRgb(): RgbColor
+    {
+        return $this->transformTo(RgbColorspace::class);
+    }
+
+    public function toCmyk(): self
+    {
+        return $this->transformTo(CmykColorspace::class);
+    }
+
+    public function __toString(): string
+    {
+        return sprintf(
+            'cmyk(%d, %d, %d, %d)',
+            $this->cyan()->value(),
+            $this->magenta()->value(),
+            $this->yellow()->value(),
+            $this->key()->value()
+        );
+    }
+}
diff --git a/src/Colors/Cmyk/Colorspace.php b/src/Colors/Cmyk/Colorspace.php
new file mode 100644
index 00000000..968bd023
--- /dev/null
+++ b/src/Colors/Cmyk/Colorspace.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Intervention\Image\Colors\Cmyk;
+
+use Intervention\Image\Colors\Rgb\Color as RgbColor;
+use Intervention\Image\Colors\Cmyk\Color as CmykColor;
+use Intervention\Image\Interfaces\ColorInterface;
+use Intervention\Image\Interfaces\ColorspaceInterface;
+
+class Colorspace implements ColorspaceInterface
+{
+    public function transformColor(ColorInterface $color): ColorInterface
+    {
+        return match (get_class($color)) {
+            RgbColor::class => $this->convertRgbColor($color),
+            default => $color,
+        };
+    }
+
+    protected function convertRgbColor(RgbColor $color): CmykColor
+    {
+        $c = (255 - $color->red()->value()) / 255.0 * 100;
+        $m = (255 - $color->green()->value()) / 255.0 * 100;
+        $y = (255 - $color->blue()->value()) / 255.0 * 100;
+        $k = intval(round(min([$c, $m, $y])));
+
+        $c = intval(round($c - $k));
+        $m = intval(round($m - $k));
+        $y = intval(round($y - $k));
+
+        return new CmykColor($c, $m, $y, $k);
+    }
+}
diff --git a/src/Colors/Rgb/Channels/Blue.php b/src/Colors/Rgb/Channels/Blue.php
new file mode 100644
index 00000000..b83be821
--- /dev/null
+++ b/src/Colors/Rgb/Channels/Blue.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Colors\Rgb\Channels;
+
+class Blue extends Red
+{
+    //
+}
diff --git a/src/Colors/Rgb/Channels/Green.php b/src/Colors/Rgb/Channels/Green.php
new file mode 100644
index 00000000..28abe607
--- /dev/null
+++ b/src/Colors/Rgb/Channels/Green.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Colors\Rgb\Channels;
+
+class Green extends Red
+{
+    //
+}
diff --git a/src/Colors/Rgb/Channels/Red.php b/src/Colors/Rgb/Channels/Red.php
new file mode 100644
index 00000000..4a4e3446
--- /dev/null
+++ b/src/Colors/Rgb/Channels/Red.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Intervention\Image\Colors\Rgb\Channels;
+
+use Intervention\Image\Exceptions\ColorException;
+use Intervention\Image\Interfaces\ColorChannelInterface;
+
+class Red implements ColorChannelInterface
+{
+    protected int $value;
+
+    public function __construct(int $value)
+    {
+        $this->value = $this->validate($value);
+    }
+
+    public function value(): int
+    {
+        return $this->value;
+    }
+
+    public function normalize($precision = 32): float
+    {
+        return round($this->value() / $this->max(), $precision);
+    }
+
+    public function min(): int
+    {
+        return 0;
+    }
+
+    public function max(): int
+    {
+        return 255;
+    }
+
+    public function validate(mixed $value): mixed
+    {
+        if ($value < $this->min() || $value > $this->max()) {
+            throw new ColorException('RGB color values must be in range 0-255.');
+        }
+
+        return $value;
+    }
+}
diff --git a/src/Colors/Rgb/Color.php b/src/Colors/Rgb/Color.php
new file mode 100644
index 00000000..18be0fc2
--- /dev/null
+++ b/src/Colors/Rgb/Color.php
@@ -0,0 +1,115 @@
+<?php
+
+namespace Intervention\Image\Colors\Rgb;
+
+use Intervention\Image\Colors\Cmyk\Color as CmykColor;
+use Intervention\Image\Colors\Cmyk\Colorspace as CmykColorspace;
+use Intervention\Image\Colors\Rgb\Channels\Blue;
+use Intervention\Image\Colors\Rgb\Channels\Green;
+use Intervention\Image\Colors\Rgb\Channels\Red;
+use Intervention\Image\Interfaces\ColorChannelInterface;
+use Intervention\Image\Interfaces\ColorInterface;
+use Intervention\Image\Interfaces\ColorspaceInterface;
+
+class Color implements ColorInterface
+{
+    protected array $channels;
+
+    public function __construct(int $r, int $g, int $b)
+    {
+        $this->channels = [
+            new Red($r),
+            new Green($g),
+            new Blue($b),
+        ];
+    }
+
+    public function channels(): array
+    {
+        return $this->channels;
+    }
+
+    public function channel(string $classname): ColorChannelInterface
+    {
+        $channels = array_filter($this->channels(), function (ColorChannelInterface $channel) use ($classname) {
+            return is_a($channel, $classname);
+        });
+
+        return reset($channels);
+    }
+
+    public function red(): Red
+    {
+        return $this->channel(Red::class);
+    }
+
+    public function green(): Green
+    {
+        return $this->channel(Green::class);
+    }
+
+    public function blue(): Blue
+    {
+        return $this->channel(Blue::class);
+    }
+
+    public function toArray(): array
+    {
+        return array_map(function (ColorChannelInterface $channel) {
+            return $channel->value();
+        }, $this->channels());
+    }
+
+    public function normalize(): array
+    {
+        return array_map(function (ColorChannelInterface $channel) {
+            return $channel->normalize();
+        }, $this->channels());
+    }
+
+    public function toHex(string $prefix = ''): string
+    {
+        return sprintf(
+            '%s%02x%02x%02x',
+            $prefix,
+            $this->red()->value(),
+            $this->green()->value(),
+            $this->blue()->value()
+        );
+    }
+
+    public function toRgb(): Color
+    {
+        return $this;
+    }
+
+    public function toInt(): int
+    {
+        return $this->red()->value() * 256 * 256 + $this->green()->value() * 256 + $this->blue()->value();
+    }
+
+    public function transformTo(string|ColorspaceInterface $colorspace): ColorInterface
+    {
+        $colorspace = match (true) {
+            is_object($colorspace) => $colorspace,
+            default => new $colorspace(),
+        };
+
+        return $colorspace->transformColor($this);
+    }
+
+    public function toCmyk(): CmykColor
+    {
+        return $this->transformTo(CmykColorspace::class);
+    }
+
+    public function __toString(): string
+    {
+        return sprintf(
+            'rgb(%d, %d, %d)',
+            $this->red()->value(),
+            $this->green()->value(),
+            $this->blue()->value()
+        );
+    }
+}
diff --git a/src/Colors/Rgb/Colorspace.php b/src/Colors/Rgb/Colorspace.php
new file mode 100644
index 00000000..fd28b1e9
--- /dev/null
+++ b/src/Colors/Rgb/Colorspace.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace Intervention\Image\Colors\Rgb;
+
+use Intervention\Image\Colors\Cmyk\Color as CmykColor;
+use Intervention\Image\Interfaces\ColorInterface;
+use Intervention\Image\Interfaces\ColorspaceInterface;
+
+class Colorspace implements ColorspaceInterface
+{
+    public function transformColor(ColorInterface $color): ColorInterface
+    {
+        return match ($color) {
+            CmykColor::class => $this->convertCmykColor($color),
+            default => $color,
+        };
+    }
+
+    protected function convertCmykColor(CmykColor $color): Color
+    {
+        return new Color(
+            (int) (255 * (1 - $color->cyan()->value()) * (1 - $color->key()->value())),
+            (int) (255 * (1 - $color->magenta()->value()) * (1 - $color->key()->value())),
+            (int) (255 * (1 - $color->yellow()->value()) * (1 - $color->key()->value())),
+        );
+    }
+}
diff --git a/src/Exceptions/ColorException.php b/src/Exceptions/ColorException.php
new file mode 100644
index 00000000..4eda9322
--- /dev/null
+++ b/src/Exceptions/ColorException.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Exceptions;
+
+class ColorException extends \RuntimeException
+{
+    //
+}
diff --git a/src/Interfaces/ColorChannelInterface.php b/src/Interfaces/ColorChannelInterface.php
new file mode 100644
index 00000000..82de01da
--- /dev/null
+++ b/src/Interfaces/ColorChannelInterface.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Intervention\Image\Interfaces;
+
+interface ColorChannelInterface
+{
+    public function value(): int;
+    public function normalize(int $precision = 32): float;
+    public function validate(mixed $value): mixed;
+    public function min(): int;
+    public function max(): int;
+}
diff --git a/src/Interfaces/ColorInterface.php b/src/Interfaces/ColorInterface.php
index 2662258d..0953402d 100644
--- a/src/Interfaces/ColorInterface.php
+++ b/src/Interfaces/ColorInterface.php
@@ -2,14 +2,18 @@
 
 namespace Intervention\Image\Interfaces;
 
+use Intervention\Image\Colors\CmykColor;
+use Intervention\Image\Colors\RgbColor;
+
 interface ColorInterface
 {
-    public function red(): int;
-    public function green(): int;
-    public function blue(): int;
-    public function alpha(): float;
-    public function toArray(): array;
-    public function toHex(string $prefix = ''): string;
-    public function toInt(): int;
-    public function isGreyscale(): bool;
+    // public function channels(): array;
+    // public function channel(string $classname): ColorChannelInterface;
+    // public function colorspace(): ColorspaceInterface;
+    // public function toRgb(): RgbColor;
+    // public function toRgba(): RgbColor;
+    // public function toCmyk(): CmykColor;
+    // public function toArray(): array;
+    // public function transformTo(string|ColorspaceInterface $colorspace): ColorInterface;
+    // public function __toString(): string;
 }
diff --git a/src/Interfaces/ColorspaceInterface.php b/src/Interfaces/ColorspaceInterface.php
new file mode 100644
index 00000000..b1dc3bd1
--- /dev/null
+++ b/src/Interfaces/ColorspaceInterface.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Intervention\Image\Interfaces;
+
+interface ColorspaceInterface
+{
+    public function transformColor(ColorInterface $color): ColorInterface;
+}
diff --git a/tests/Colors/Rgb/ColorTest.php b/tests/Colors/Rgb/ColorTest.php
new file mode 100644
index 00000000..31e4436b
--- /dev/null
+++ b/tests/Colors/Rgb/ColorTest.php
@@ -0,0 +1,106 @@
+<?php
+
+namespace Intervention\Image\Tests\Colors\Rgb;
+
+use Intervention\Image\Colors\Rgb\Channels\Red;
+use Intervention\Image\Colors\Rgb\Channels\Green;
+use Intervention\Image\Colors\Rgb\Channels\Blue;
+use Intervention\Image\Colors\Rgb\Color as Color;
+use Intervention\Image\Tests\TestCase;
+
+/**
+ * @requires extension gd
+ * @covers \Intervention\Image\Colors\Rgb\Color
+ */
+class ColorTest extends TestCase
+{
+    public function testConstructor(): void
+    {
+        $color = new Color(0, 0, 0);
+        $this->assertInstanceOf(Color::class, $color);
+    }
+
+    public function testChannels(): void
+    {
+        $color = new Color(10, 20, 30);
+        $this->assertIsArray($color->channels());
+        $this->assertCount(3, $color->channels());
+    }
+
+    public function testChannel(): void
+    {
+        $color = new Color(10, 20, 30);
+        $channel = $color->channel(Red::class);
+        $this->assertInstanceOf(Red::class, $channel);
+        $this->assertEquals(10, $channel->value());
+    }
+
+    public function testRedGreenBlue(): void
+    {
+        $color = new Color(10, 20, 30);
+        $this->assertInstanceOf(Red::class, $color->red());
+        $this->assertInstanceOf(Green::class, $color->green());
+        $this->assertInstanceOf(Blue::class, $color->blue());
+        $this->assertEquals(10, $color->red()->value());
+        $this->assertEquals(20, $color->green()->value());
+        $this->assertEquals(30, $color->blue()->value());
+    }
+
+    public function testToArray(): void
+    {
+        $color = new Color(10, 20, 30);
+        $this->assertEquals([10, 20, 30], $color->toArray());
+    }
+
+    public function testToHex(): void
+    {
+        $color = new Color(181, 55, 23);
+        $this->assertEquals('b53717', $color->toHex());
+        $this->assertEquals('#b53717', $color->toHex('#'));
+    }
+
+    public function testNormalize(): void
+    {
+        $color = new Color(255, 0, 51);
+        $this->assertEquals([1.0, 0.0, 0.2], $color->normalize());
+    }
+
+    public function testToInt(): void
+    {
+        $color = new Color(0, 0, 0);
+        $this->assertEquals(0, $color->toInt());
+
+        $color = new Color(255, 255, 255);
+        $this->assertEquals(16777215, $color->toInt());
+
+        $color = new Color(181, 55, 23);
+        $this->assertEquals(11876119, $color->toInt());
+    }
+
+    public function testToString(): void
+    {
+        $color = new Color(181, 55, 23);
+        $this->assertEquals('rgb(181, 55, 23)', (string) $color);
+    }
+
+    public function testToCmyk(): void
+    {
+        $color = new Color(0, 0, 0);
+        $this->assertEquals([0, 0, 0, 100], $color->toCmyk()->toArray());
+
+        $color = new Color(255, 255, 255);
+        $this->assertEquals([0, 0, 0, 0], $color->toCmyk()->toArray());
+
+        $color = new Color(255, 0, 0);
+        $this->assertEquals([0, 100, 100, 0], $color->toCmyk()->toArray());
+
+        $color = new Color(255, 0, 255);
+        $this->assertEquals([0, 100, 0, 0], $color->toCmyk()->toArray());
+
+        $color = new Color(255, 255, 0);
+        $this->assertEquals([0, 0, 100, 0], $color->toCmyk()->toArray());
+
+        $color = new Color(255, 204, 204);
+        $this->assertEquals([0, 20, 20, 0], $color->toCmyk()->toArray());
+    }
+}