Merge branch 'PHP-5.6'

* PHP-5.6:
  Added basic test for imagewebp() and imagecreatefromwebp()

Author: cmb69

ext/gd/tests/similarity.inc

@@ -0,0 +1,64 @@
+<?php
+
+/**
+ * A very simple algorithm for finding the dissimilarity between images,
+ * mainly useful for checking lossy compression.
+ */
+
+/**
+ * Gets the individual components of an RGB value.
+ *
+ * @param int $color
+ * @param int $red
+ * @param int $green
+ * @param int $blue
+ *
+ * @return void
+ */
+function get_rgb($color, &$red, &$green, &$blue)
+{
+    // assumes $color is an RGB value
+    $red = ($color >> 16) & 0xFF;
+    $green = ($color >> 8) & 0xFF;
+    $blue = $color & 0xFF;
+}
+
+/**
+ * Calculates the euclidean distance of two RGB values.
+ *
+ * @param int $color1
+ * @param int $color2
+ *
+ * @return int
+ */
+function calc_pixel_distance($color1, $color2)
+{
+    get_rgb($color1, $red1, $green1, $blue1);
+    get_rgb($color2, $red2, $green2, $blue2);
+    return sqrt(
+        pow($red1 - $red2, 2) + pow($green1 - $green2, 2) + pow($blue1 - $blue2, 2)
+    );
+}
+
+/**
+ * Calculates dissimilarity of two images.
+ *
+ * @param resource $image1
+ * @param resource $image2
+ *
+ * @return int The dissimilarity. 0 means the images are identical. The higher
+ *             the value, the more dissimilar are the images.
+ */
+function calc_image_dissimilarity($image1, $image2)
+{
+    // assumes image1 and image2 have same width and height
+    $dissimilarity = 0;
+    for ($i = 0, $n = imagesx($image1); $i < $n; $i++) {
+        for ($j = 0, $m = imagesy($image1); $j < $m; $j++) {
+            $color1 = imagecolorat($image1, $i, $j);
+            $color2 = imagecolorat($image2, $i, $j);
+            $dissimilarity += calc_pixel_distance($color1, $color2);
+        }
+    }
+    return $dissimilarity;
+}

ext/gd/tests/webp_basic.phpt

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+--TEST--
+imagewebp() and imagecreatefromwebp() - basic test
+--SKIPIF--
+<?php
+if (!extension_loaded('gd')) die('skip gd extension not available');
+if (!function_exists('imagewebp') || !function_exists('imagecreatefromwebp'))
+    die('skip WebP support not available');
+?>
+--FILE--
+<?php
+require_once __DIR__ . '/similarity.inc';
+
+$filename = __DIR__ . '/webp_basic.webp';
+
+$im1 = imagecreatetruecolor(75, 75);
+$white = imagecolorallocate($im1, 255, 255, 255);
+$red = imagecolorallocate($im1, 255, 0, 0);
+$green = imagecolorallocate($im1, 0, 255, 0);
+$blue = imagecolorallocate($im1, 0, 0, 255);
+imagefilledrectangle($im1, 0, 0, 74, 74, $white);
+imageline($im1, 3, 3, 71, 71, $red);
+imageellipse($im1, 18, 54, 36, 36, $green);
+imagerectangle($im1, 41, 3, 71, 33, $blue);
+imagewebp($im1, $filename);
+
+$im2 = imagecreatefromwebp($filename);
+imagewebp($im2, $filename);
+var_dump(calc_image_dissimilarity($im1, $im2) < 10e5);
+?>
+--CLEAN--
+<?php
+@unlink(__DIR__ . '/webp_basic.webp');
+?>
+--EXPECT--
+bool(true)