add setOpacity

docs/classes/DantSu/PHPImageEditor/Image.md

@@ -55,6 +55,7 @@ DantSu\PHPImageEditor\Image is PHP library to easily edit image with GD extensio
 - [pasteOn](#-pasteon) 
 - [pasteGdImageOn](#-pastegdimageon) 
 - [alphaMask](#-alphamask) 
+- [setOpacity](#-setopacity) 
 - [grayscale](#-grayscale) 
 - [writeText](#-writetext) 
 - [writeTextAndGetBoundingBox](#-writetextandgetboundingbox) 
@@ -781,6 +782,31 @@ Use a grayscale image (`$mask`) to apply transparency to the image.
 
 
 
+---
+### ->setOpacity
+
+change the image opacity
+
+
+
+
+
+
+
+
+#### Parameters:
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `opacity` | **float** | Opacity (0 to 1) |
+
+
+#### Return Value:
+
+ **$this** : Fluent interface
+
+
+
 ---
 ### ->grayscale
 
@@ -1404,4 +1430,4 @@ Get image GIF base64 data for <img src=""> tag.
 
 
 ---
-> Automatically generated from source code comments on 2022-05-24 using [phpDocumentor](http://www.phpdoc.org/)
+> Automatically generated from source code comments on 2022-05-30 using [phpDocumentor](http://www.phpdoc.org/)

docs/index.md

@@ -19,4 +19,4 @@ This is an automatically generated documentation for **PHP Image Editor**.
 
 
 ---
-> Automatically generated from source code comments on 2022-05-24 using [phpDocumentor](http://www.phpdoc.org/)
+> Automatically generated from source code comments on 2022-05-30 using [phpDocumentor](http://www.phpdoc.org/)

src/Image.php

@@ -136,7 +136,7 @@ public function resetCanvas(int $width, int $height): Image
 
         \imagealphablending($this->image, false);
         \imagesavealpha($this->image, true);
-        \imagecolortransparent($this->image, \imagecolorallocate($this->image, 0, 0, 0));
+        \imagefill($this->image, 0, 0, \imagecolorallocatealpha($this->image, 0, 0, 0, 127));
 
         $this->width = $width;
         $this->height = $height;
@@ -478,14 +478,9 @@ public function resize(int $width, int $height): Image
             return $this;
         }
 
-        if (
-            ($image = \imagecreatetruecolor($width, $height)) !== false &&
-            \imagealphablending($image, false) !== false &&
-            \imagesavealpha($image, true) !== false &&
-            ($transparent = $this->colorAllocate('#000000FF')) !== false &&
-            \imagefill($image, 0, 0, $transparent) !== false &&
-            \imagecopyresampled($image, $this->image, 0, 0, 0, 0, $width, $height, $this->width, $this->height) !== false
-        ) {
+        $image = Image::newCanvas($width, $height)->getImage();
+
+        if (\imagecopyresampled($image, $this->image, 0, 0, 0, 0, $width, $height, $this->width, $this->height) !== false) {
             $this->image = $image;
             $this->width = $width;
             $this->height = $height;
@@ -512,7 +507,6 @@ public function downscaleAndCrop(int $width, int $height, $posX = Image::ALIGN_C
             $height = $this->height;
         }
 
-
         $finalWidth = \round($this->width * $height / $this->height);
         $finalHeight = $height;
 
@@ -724,6 +718,10 @@ public function alphaMask(Image $mask): Image
 
                 if ($alpha != 127) {
                     $rgb = \imagecolorat($this->image, $j, $i);
+                    $alpha = 127 - \ceil((127 - (($rgb >> 24) & 0x7F)) * (127 - $alpha) / 127);
+                }
+
+                if ($alpha != 127) {
                     $red = ($rgb >> 16) & 0xFF;
                     $green = ($rgb >> 8) & 0xFF;
                     $blue = $rgb & 0xFF;
@@ -746,6 +744,25 @@ public function alphaMask(Image $mask): Image
         return $this;
     }
 
+    /**
+     * change the image opacity
+     *
+     * @param float $opacity Opacity (0 to 1)
+     * @return $this Fluent interface
+     */
+    public function setOpacity(float $opacity): Image
+    {
+        if (!$this->isImageDefined()) {
+            return $this;
+        }
+
+        \imagealphablending($this->image, false);
+        \imagesavealpha($this->image, true);
+        \imagefilter($this->image, IMG_FILTER_COLORIZE, 0, 0, 0, 127 * (1 - $opacity));
+
+        return $this;
+    }
+
     //===============================================================================================================================
     //=========================================================POST PROD=============================================================
     //===============================================================================================================================
@@ -1204,18 +1221,17 @@ public function displayGIF()
     /**
      * Get image raw data
      *
-     * @param string $nameFunction Image function to be called
-     * @param int $quality JPG quality : 0 to 100
+     * @param callable $imgFunction Image function to be called
      * @return string Data
      */
-    private function getData(string $nameFunction, int $quality = -1): string
+    private function getData(callable $imgFunction): string
     {
         if (!$this->isImageDefined()) {
             return '';
         }
 
         \ob_start();
-        $nameFunction($this->image, null, $quality, -1);
+        $imgFunction();
         $image_data = \ob_get_contents();
         \ob_end_clean();
 
@@ -1229,7 +1245,7 @@ private function getData(string $nameFunction, int $quality = -1): string
      */
     public function getDataPNG(): string
     {
-        return $this->getData('imagepng');
+        return $this->getData(function () {$this->displayPNG();});
     }
 
     /**
@@ -1240,7 +1256,7 @@ public function getDataPNG(): string
      */
     public function getDataJPG(int $quality = -1): string
     {
-        return $this->getData('imagejpeg', $quality);
+        return $this->getData(function () use ($quality) {$this->displayJPG($quality);});
     }
 
     /**
@@ -1250,7 +1266,7 @@ public function getDataJPG(int $quality = -1): string
      */
     public function getDataGIF(): string
     {
-        return $this->getData('imagegif');
+        return $this->getData(function () {$this->displayGIF();});
     }
 
     /**

src/samples/sample4.php

@@ -14,8 +14,9 @@
     ->drawCircle(450, 600, 200, '#FFFFFF88')
     ->pasteOn(
         Image::newCanvas(1920, 1080)
-            ->drawPolygon([1110, 500, 1240, 250, 1400, 140, 1650, 280, 1400, 400, 1800, 510, 1400, 950, 1180, 620, 1230, 540], '#88229988')
-            ->drawCircle(1450, 600, 200, '#FFFFFF88'),
+            ->drawPolygon([1110, 500, 1240, 250, 1400, 140, 1650, 280, 1400, 400, 1800, 510, 1400, 950, 1180, 620, 1230, 540], '#882299')
+            ->drawCircle(1450, 600, 200)
+            ->setOpacity(0.6),
         0,
         0
     )

src/samples/sample5.php

@@ -0,0 +1,14 @@
+<?php
+
+require_once '../Geometry2D.php';
+require_once '../Image.php';
+
+use \DantSu\PHPImageEditor\Image;
+
+\header('Content-type: image/png');
+
+Image::fromPath(__DIR__ . '/resources/sample5_base.png')
+    ->alphaMask(Image::fromPath(__DIR__ . '/resources/sample5_mask.png'))
+    ->crop(494, 494, 9, 12)
+    ->setOpacity(0.5)
+    ->displayPNG();