Merge pull request #5 from kellegous/drawing

added basic drawing

.github/workflows/php.yml

@@ -1,4 +1,4 @@
-name: PHP Composer
+name: Validation
 
 on:
   push:

bin/test.php

@@ -2,8 +2,19 @@
 
 declare(strict_types=1);
 
+use Kellegous\Algs4\Graphics\Destination;
+use Kellegous\Algs4\Graphics\Drawing;
+
 require __DIR__ . '/../vendor/autoload.php';
 
-var_dump(
-    ['3' => 1]
-);
+$m = new Drawing(800, 600);
+$m->floodFill(400, 300, $m->colorFromRGB(0xff, 0xff, 0xff));
+$m->ellipse(400, 300, 200, 150)
+    ->fill($m->colorFromRGBA(0, 0, 0, 200));
+$m->writePNG(Destination::toFile('test.png'));
+
+$a = $m->colorFromRGB(0xff, 0xff, 0xff);
+var_dump($a->alpha());
+printf("%x\n", $a->getID());
+$b = $m->colorFromRGBA(0xff, 0xff, 0xff, 127);
+printf("alpha = %x\n", $b->alpha());

composer.json

@@ -11,6 +11,7 @@
   ],
   "require": {
     "php": "^8.3",
+    "ext-gd": "*",
     "symfony/console": "^7.0"
   },
   "require-dev": {

src/Graphics/Color.php

@@ -0,0 +1,114 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kellegous\Algs4\Graphics;
+
+/**
+ * Representation of an RGBA color.
+ */
+final readonly class Color
+{
+    /**
+     * @param int $id
+     */
+    private function __construct(
+        private int $id
+    ) {
+    }
+
+    /**
+     * Create a new opaque color from the given RGB values.
+     * @param Drawing $drawing
+     * @param int<0,255> $r
+     * @param int<0,255> $g
+     * @param int<0,255> $b
+     * @return self
+     * @throws Exception
+     * @see Drawing::colorFromRGB()
+     */
+    public static function fromRGB(
+        Drawing $drawing,
+        int $r,
+        int $g,
+        int $b,
+    ): self {
+        $c = imagecolorallocate($drawing->getImage(), $r, $g, $b);
+        if ($c === false) {
+            throw new Exception('unable to allocate color');
+        }
+        return new self($c);
+    }
+
+    /**
+     * Create a new opaque color from the given RGB values.
+     * @param Drawing $drawing
+     * @param int<0,255> $r
+     * @param int<0,255> $g
+     * @param int<0,255> $b
+     * @param int<0,255> $a
+     * @return self
+     * @throws Exception
+     */
+    public static function fromRGBA(
+        Drawing $drawing,
+        int $r,
+        int $g,
+        int $b,
+        int $a,
+    ): self {
+        $c = imagecolorallocatealpha($drawing->getImage(), $r, $g, $b, $a >> 1);
+        if ($c === false) {
+            throw new Exception('unable to allocate color');
+        }
+        return new self($c);
+    }
+
+    /**
+     * Get the GD color index. This will be the color as an integer.
+     * @return int
+     * @internal
+     */
+    public function getID(): int
+    {
+        return $this->id;
+    }
+
+    /**
+     * Get the red component of the color.
+     * @return int<0,255>
+     */
+    public function red(): int
+    {
+        return ($this->id >> 16) & 0xff;
+    }
+
+    /**
+     * Get the green component of the color.
+     * @return int<0,255>
+     */
+    public function green(): int
+    {
+        return ($this->id >> 8) & 0xff;
+    }
+
+    /**
+     * Get the blue component of the color.
+     * @return int<0,255>
+     */
+    public function blue(): int
+    {
+        return $this->id & 0xff;
+    }
+
+    /**
+     * Get the alpha component of the color.
+     * @return int<0,255>
+     */
+    public function alpha(): int
+    {
+        $a = (($this->id >> 24) & 0xff) << 1;
+        assert($a >= 0 && $a <= 255);
+        return $a;
+    }
+}

src/Graphics/Destination.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kellegous\Algs4\Graphics;
+
+/**
+ * An ouput destination for a drawing.
+ */
+final readonly class Destination
+{
+    /**
+     * @param resource|string $destination
+     */
+    private function __construct(private mixed $destination)
+    {
+    }
+
+    /**
+     * Create a destination that writes to the given stream.
+     * @param resource $destination
+     * @return self
+     */
+    public static function toStream(mixed $destination): self
+    {
+        return new self($destination);
+    }
+
+    /**
+     * Create a destination that writes to the given file.
+     * @param string $path
+     * @return self
+     */
+    public static function toFile(string $path): self
+    {
+        return new self($path);
+    }
+
+    /**
+     * @return resource|string
+     * @internal
+     */
+    public function get(): mixed
+    {
+        return $this->destination;
+    }
+}

src/Graphics/Drawing.php

@@ -0,0 +1,150 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kellegous\Algs4\Graphics;
+
+use GdImage;
+
+/**
+ *
+ */
+final readonly class Drawing
+{
+    /**
+     * @var GdImage
+     */
+    private GdImage $im;
+
+    /**
+     * @param int $width
+     * @param int $height
+     * @param bool $with_alpha_blending
+     * @param bool $with_antialiasing
+     * @throws Exception
+     */
+    public function __construct(
+        int $width,
+        int $height,
+        bool $with_alpha_blending = true,
+        bool $with_antialiasing = true
+    ) {
+        $im = imagecreatetruecolor($width, $height);
+        if ($im === false) {
+            throw new Exception('unable to create image');
+        }
+
+        if (!imagealphablending($im, $with_alpha_blending)) {
+            throw new Exception('unable to set alpha blending');
+        }
+
+        if (!imageantialias($im, $with_antialiasing)) {
+            throw new Exception('unable to set antialiasing');
+        }
+        $this->im = $im;
+    }
+
+    /**
+     * @return GdImage
+     * @internal
+     */
+    public function getImage(): GdImage
+    {
+        return $this->im;
+    }
+
+    /**
+     * @param Destination $dest
+     * @param int $quality
+     * @param int $filters
+     * @return void
+     * @throws Exception
+     */
+    public function writePNG(
+        Destination $dest,
+        int $quality = -1,
+        int $filters = -1,
+    ): void {
+        if (!imagepng($this->im, $dest->get(), $quality, $filters)) {
+            throw new Exception('unable to write PNG');
+        }
+    }
+
+    /**
+     * @param Destination $dest
+     * @param int $quality
+     * @return void
+     * @throws Exception
+     */
+    public function writeJPEG(
+        Destination $dest,
+        int $quality = -1,
+    ): void {
+        if (!imagejpeg($this->im, $dest->get(), $quality)) {
+            throw new Exception('unable to write JPEG');
+        }
+    }
+
+    /**
+     * @param int<0,255> $r
+     * @param int<0,255> $g
+     * @param int<0,255> $b
+     * @return Color
+     * @throws Exception
+     */
+    public function colorFromRGB(int $r, int $g, int $b): Color
+    {
+        return Color::fromRGB($this, $r, $g, $b);
+    }
+
+    /**
+     * @param int<0,255> $r
+     * @param int<0,255> $g
+     * @param int<0,255> $b
+     * @param int<0,255> $a
+     * @return Color
+     * @throws Exception
+     */
+    public function colorFromRGBA(int $r, int $g, int $b, int $a): Color
+    {
+        return Color::fromRGBA($this, $r, $g, $b, $a);
+    }
+
+    /**
+     * @param int $x1
+     * @param int $y1
+     * @param int $x2
+     * @param int $y2
+     * @return Rectangle
+     */
+    public function rectangle(int $x1, int $y1, int $x2, int $y2): Rectangle
+    {
+        return new Rectangle($this, $x1, $y1, $x2, $y2);
+    }
+
+    /**
+     * @param int $center_x
+     * @param int $center_y
+     * @param int $width
+     * @param int $height
+     * @return Ellipse
+     */
+    public function ellipse(int $center_x, int $center_y, int $width, int $height): Ellipse
+    {
+        return new Ellipse($this, $center_x, $center_y, $width, $height);
+    }
+
+    /**
+     * @param int $x
+     * @param int $y
+     * @param Color $color
+     * @return void
+     * @throws Exception
+     */
+    public function floodFill(int $x, int $y, Color $color): void
+    {
+        if (!imagefill($this->im, $x, $y, $color->getID())) {
+            throw new Exception('unable to flood fill');
+        }
+    }
+}