ext/gd adding imagecompare.

can be useful to detect subtle differences between two images,
size, transparent, background ... wise.

Author: devnexen

ext/gd/gd.c

@@ -4337,6 +4337,21 @@ PHP_FUNCTION(imageresolution)
 }
 /* }}} */
 
+PHP_FUNCTION(imagecompare)
+{
+	zval *IM1, *IM2;
+	gdImagePtr im1, im2;
+
+	ZEND_PARSE_PARAMETERS_START(2, 2)
+		Z_PARAM_OBJECT_OF_CLASS(IM1, gd_image_ce)
+		Z_PARAM_OBJECT_OF_CLASS(IM2, gd_image_ce)
+	ZEND_PARSE_PARAMETERS_END();
+
+	im1 = php_gd_libgdimageptr_from_zval_p(IM1);
+	im2 = php_gd_libgdimageptr_from_zval_p(IM2);
+
+	RETURN_LONG((zend_long)gdImageCompare(im1, im2));
+}
 
 /*********************************************************
  *

ext/gd/gd.stub.php

@@ -338,6 +338,52 @@
  */
 const IMG_AFFINE_SHEAR_VERTICAL = UNKNOWN;
 
+/**
+ * @var int
+ * @cvalue GD_CMP_IMAGE
+ */
+const IMG_CMP_IMAGE = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_NUM_COLORS
+ */
+const IMG_CMP_NUM_COLORS = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_COLOR
+ */
+const IMG_CMP_COLOR = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_SIZE_X
+ */
+const IMG_CMP_SIZE_X = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_SIZE_Y
+ */
+const IMG_CMP_SIZE_Y = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_TRANSPARENT
+ */
+const IMG_CMP_TRANSPARENT = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_BACKGROUND
+ */
+const IMG_CMP_BACKGROUND = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_INTERLACE
+ */
+const IMG_CMP_INTERLACE = UNKNOWN;
+/**
+ * @var int
+ * @cvalue GD_CMP_TRUECOLOR
+ */
+const IMG_CMP_TRUECOLOR = UNKNOWN;
+
 /**
  * @var int
  * @cvalue GD_BUNDLED
@@ -794,3 +840,5 @@ function imagesetinterpolation(GdImage $image, int $method = IMG_BILINEAR_FIXED)
  * @refcount 1
  */
 function imageresolution(GdImage $image, ?int $resolution_x = null, ?int $resolution_y = null): array|bool {}
+
+function imagecompare(GdImage $image1, GdImage $image2): int {}

ext/gd/gd_arginfo.h

@@ -0,0 +1,30 @@
+--TEST--
+imagefilter() function test
+--EXTENSIONS--
+gd
+--SKIPIF--
+<?php
+    if (!(imagetypes() & IMG_PNG)) die("skip No PNG support");
+?>
+--FILE--
+<?php
+$SAVE_DIR = __DIR__;
+$SOURCE_IMG = $SAVE_DIR . "/test.png";
+$im1 = imagecreatefrompng($SOURCE_IMG);
+$im2 = imagecreatefrompng($SOURCE_IMG);
+
+var_dump(imagecompare($im1, $im2) === 0);
+
+$cl = imagecolorallocate($im2, 255, 0, 0);
+imagecolortransparent($im2, $cl);
+var_dump((imagecompare($im1, $im2) & IMG_CMP_TRANSPARENT) === IMG_CMP_TRANSPARENT);
+
+$im3 = imagecreate(10, 10);
+imagecopyresized($im3, $im2, 0, 0, 0, 0, 10, 10, 10, 10);
+var_dump((imagecompare($im1, $im3) & IMG_CMP_SIZE_X) !== 0);
+var_dump((imagecompare($im1, $im3) & IMG_CMP_SIZE_Y) !== 0);
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)
+bool(true)