test(color): add unit tests for color mode conversions

Author: vlakoff

test/Renderer/Color/CmykTest.php

@@ -0,0 +1,62 @@
+<?php
+declare(strict_types = 1);
+
+namespace BaconQrCodeTest\Renderer\Color;
+
+use BaconQrCode\Renderer\Color\Cmyk;
+use BaconQrCode\Renderer\Color\Gray;
+use BaconQrCode\Renderer\Color\Rgb;
+use PHPUnit\Framework\TestCase;
+
+final class CmykTest extends TestCase
+{
+    /**
+     * Tests CMYK to RGB conversion, focusing on correct application of rounding.
+     */
+    public function testToRgb() : void
+    {
+        // Pure Black (C:0, M:0, Y:0, K:100) -> RGB(0, 0, 0)
+        $cmykBlack = new Cmyk(0, 0, 0, 100);
+        $this->assertEquals(new Rgb(0, 0, 0), $cmykBlack->toRgb(), 'CMYK Black to RGB');
+
+        // Pure White (C:0, M:0, Y:0, K:0) -> RGB(255, 255, 255)
+        $cmykWhite = new Cmyk(0, 0, 0, 0);
+        $this->assertEquals(new Rgb(255, 255, 255), $cmykWhite->toRgb(), 'CMYK White to RGB');
+
+        // Mid Gray (C:0, M:0, Y:0, K:50) -> RGB(128, 128, 128)
+        // Check for rounding: 255 * (1 - 0) * (1 - 0.5) = 127.5 -> round(127.5) = 128
+        $cmykGray = new Cmyk(0, 0, 0, 50);
+        $this->assertEquals(new Rgb(128, 128, 128), $cmykGray->toRgb(), 'CMYK Gray to RGB (rounding check)');
+
+        // Complex Color (Dark Red): C:10, M:80, Y:70, K:30
+        // R: round(255 * 0.9 * 0.7) = round(160.65) = 161
+        // G: round(255 * 0.2 * 0.7) = round(35.7) = 36
+        // B: round(255 * 0.3 * 0.7) = round(53.55) = 54
+        $cmykColor = new Cmyk(10, 80, 70, 30);
+        $this->assertEquals(new Rgb(161, 36, 54), $cmykColor->toRgb(), 'CMYK Complex Color to RGB');
+    }
+
+    public function testToCmyk() : void
+    {
+        $cmyk = new Cmyk(10, 20, 30, 40);
+        $this->assertSame($cmyk, $cmyk->toCmyk(), 'toCmyk should return $this');
+    }
+
+    /**
+     * Tests CMYK to Gray conversion via RGB.
+     */
+    public function testToGray() : void
+    {
+        // White (K:0) -> Gray(100)
+        $cmykWhite = new Cmyk(0, 0, 0, 0);
+        $this->assertEquals(new Gray(100), $cmykWhite->toGray(), 'CMYK White to Gray');
+
+        // Black (K:100) -> Gray(0)
+        $cmykBlack = new Cmyk(0, 0, 0, 100);
+        $this->assertEquals(new Gray(0), $cmykBlack->toGray(), 'CMYK Black to Gray');
+
+        // Pure Gray (K:50) -> Should result in Gray(50)
+        $cmykGray = new Cmyk(0, 0, 0, 50);
+        $this->assertEquals(new Gray(50), $cmykGray->toGray(), 'CMYK Gray to Gray');
+    }
+}

test/Renderer/Color/GrayTest.php

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+<?php
+declare(strict_types = 1);
+
+namespace BaconQrCodeTest\Renderer\Color;
+
+use BaconQrCode\Renderer\Color\Cmyk;
+use BaconQrCode\Renderer\Color\Gray;
+use BaconQrCode\Renderer\Color\Rgb;
+use PHPUnit\Framework\TestCase;
+
+final class GrayTest extends TestCase
+{
+    /**
+     * Tests Gray to RGB conversion, focusing on using 255/100 and correct rounding.
+     */
+    public function testToRgb() : void
+    {
+        // Black (0) -> RGB(0, 0, 0)
+        $grayBlack = new Gray(0);
+        $this->assertEquals(new Rgb(0, 0, 0), $grayBlack->toRgb(), 'Gray Black to RGB');
+
+        // White (100) -> RGB(255, 255, 255)
+        // 100 * 255 / 100 = 255
+        $grayWhite = new Gray(100);
+        $this->assertEquals(new Rgb(255, 255, 255), $grayWhite->toRgb(), 'Gray White to RGB');
+
+        // Midpoint (50) -> RGB(128, 128, 128)
+        // Check for rounding: 50 * 255 / 100 = 127.5 -> round(127.5) = 128
+        $grayMiddle = new Gray(50);
+        $this->assertEquals(new Rgb(128, 128, 128), $grayMiddle->toRgb(), 'Gray 50 to RGB (rounding check)');
+
+        // Custom value checking rounding
+        // 33 * 255 / 100 = 84.15 -> round(84.15) = 84
+        $grayCustom = new Gray(33);
+        $this->assertEquals(new Rgb(84, 84, 84), $grayCustom->toRgb(), 'Gray Custom to RGB');
+    }
+
+    /**
+     * Tests Gray to CMYK conversion (K=100-Gray).
+     */
+    public function testToCmyk() : void
+    {
+        // Black (0) -> K:100
+        $grayBlack = new Gray(0);
+        $this->assertEquals(new Cmyk(0, 0, 0, 100), $grayBlack->toCmyk(), 'Gray Black to CMYK');
+
+        // White (100) -> K:0
+        $grayWhite = new Gray(100);
+        $this->assertEquals(new Cmyk(0, 0, 0, 0), $grayWhite->toCmyk(), 'Gray White to CMYK');
+
+        // Middle (50) -> K:50
+        $grayMiddle = new Gray(50);
+        $this->assertEquals(new Cmyk(0, 0, 0, 50), $grayMiddle->toCmyk(), 'Gray Middle to CMYK');
+    }
+
+    public function testToGray() : void
+    {
+        $gray = new Gray(75);
+        $this->assertSame($gray, $gray->toGray(), 'toGray should return $this');
+    }
+}

test/Renderer/Color/RgbTest.php

@@ -0,0 +1,78 @@
+<?php
+declare(strict_types = 1);
+
+namespace BaconQrCodeTest\Renderer\Color;
+
+use BaconQrCode\Renderer\Color\Cmyk;
+use BaconQrCode\Renderer\Color\Gray;
+use BaconQrCode\Renderer\Color\Rgb;
+use PHPUnit\Framework\TestCase;
+
+final class RgbTest extends TestCase
+{
+    public function testToRgb() : void
+    {
+        $rgb = new Rgb(10, 20, 30);
+        $this->assertSame($rgb, $rgb->toRgb(), 'toRgb should return $this');
+    }
+
+    /**
+     * Tests RGB to CMYK conversion, focusing on:
+     * 1. Handling the special case RGB(0, 0, 0) -> CMYK(0, 0, 0, 100).
+     * 2. Correct application of rounding.
+     */
+    public function testToCmyk() : void
+    {
+        // Special Case: Black (0, 0, 0) -> C:0, M:0, Y:0, K:100
+        $rgbBlack = new Rgb(0, 0, 0);
+        $this->assertEquals(new Cmyk(0, 0, 0, 100), $rgbBlack->toCmyk(), 'RGB Black to CMYK (special case)');
+
+        // White (255, 255, 255) -> C:0, M:0, Y:0, K:0
+        $rgbWhite = new Rgb(255, 255, 255);
+        $this->assertEquals(new Cmyk(0, 0, 0, 0), $rgbWhite->toCmyk(), 'RGB White to CMYK');
+
+        // Pure Red (255, 0, 0) -> C:0, M:100, Y:100, K:0
+        $rgbRed = new Rgb(255, 0, 0);
+        $this->assertEquals(new Cmyk(0, 100, 100, 0), $rgbRed->toCmyk(), 'RGB Red to CMYK');
+
+        // Complex Color checking rounding: RGB(100, 150, 200)
+        // K=22 (round(100 * 0.2156))
+        // C=50 (round(100 * 0.3922 / 0.7844))
+        // M=25 (round(100 * 0.1961 / 0.7844))
+        // Y=0
+        $rgbCustom = new Rgb(100, 150, 200);
+        $this->assertEquals(new Cmyk(50, 25, 0, 22), $rgbCustom->toCmyk(), 'RGB Custom to CMYK (rounding check)');
+    }
+
+    /**
+     * Tests RGB to Gray conversion, focusing on:
+     * 1. Correct luminance coefficients (2126, 7152, 722).
+     * 2. Integer-based calculation (division by 25500).
+     * 3. Correct application of rounding.
+     */
+    public function testToGray() : void
+    {
+        // Black (0, 0, 0) -> Gray(0)
+        $rgbBlack = new Rgb(0, 0, 0);
+        $this->assertEquals(new Gray(0), $rgbBlack->toGray(), 'RGB Black to Gray');
+
+        // White (255, 255, 255) -> Gray(100)
+        $rgbWhite = new Rgb(255, 255, 255);
+        $this->assertEquals(new Gray(100), $rgbWhite->toGray(), 'RGB White to Gray');
+
+        // Pure Red (255, 0, 0)
+        // round((255 * 2126) / 25500) = round(21.26) = 21
+        $rgbRed = new Rgb(255, 0, 0);
+        $this->assertEquals(new Gray(21), $rgbRed->toGray(), 'RGB Red to Gray');
+
+        // Pure Green (0, 255, 0)
+        // round((255 * 7152) / 25500) = round(71.52) = 72
+        $rgbGreen = new Rgb(0, 255, 0);
+        $this->assertEquals(new Gray(72), $rgbGreen->toGray(), 'RGB Green to Gray');
+
+        // Complex Color checking rounding: RGB(100, 150, 200)
+        // round((100*2126 + 150*7152 + 200*722) / 25500) = round(56.07...) = 56
+        $rgbCustom = new Rgb(100, 150, 200);
+        $this->assertEquals(new Gray(56), $rgbCustom->toGray(), 'RGB Custom to Gray (rounding check)');
+    }
+}