From 823f7e60d88c826389be9502a10f93dbbe5f1ba1 Mon Sep 17 00:00:00 2001
From: Chris <christian@haschek.at>
Date: Sun, 26 Aug 2018 15:50:10 +0200
Subject: [PATCH] added gradient support. closes #55

---
 README.md                 | 13 ++-------
 inc/core.php              | 21 +++++++++++++-
 models/pictsharemodel.php | 59 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 578e97c..68e9c12 100644
--- a/README.md
+++ b/README.md
@@ -79,17 +79,6 @@ By using this compose file, you should know that:
 - (optional) You can and should put a [nginx](https://www.nginx.com/) proxy before the Apache server. That thing is just insanely fast with static content like images.
 - (optional) To secure your traffic I'd highly recommend getting an [SSL Cert](https://letsencrypt.org/) for your server if you don't already have one.
 
-
-UPDATES
-========
-- Nov. 23: Added support for MP4 uploads and conversion from gif to MP4
-- Nov. 12: Created new git project: [Pictshare stats](https://github.com/chrisiaut/pictshare_stats)
-- Nov. 07: Added 9 new (instagram-like) filters
-- Nov. 06: Master delete code. One code to delete them all
-- Nov. 01: [Restricted uploads and option-use](#restriction-settings)
-- Oct. 30: [Rotations and filters](#smart-query-system)
-- Oct. 10: [Album functionality](#smart-query-system) finally ready
-
 ## Why would I want to host my own images?
 If you own a server (even a home server) you can host your own PictShare instance so you have full control over your content and can delete images hasslefree.
 
@@ -106,10 +95,12 @@ If you're a blogger like myself, you can use it as storage for your images so th
 - MP4 resizing
 - PictShare removes all exif data so you can upload photos from your phone and all GPS tags and camera model info get wiped
 - Smart [resize, filter and rotation](#smart-query-system) features
+- Generate gradients by specifying only a size. eg: https://pictshare.net/800x200
 - Duplicates don't take up space. If the exact same images is uploaded twice, the second upload will link to the first
 - You can control who can upload images or use filters/resizes by defining an [upload-code](#restriction-settings)
 - You can set a code in your ```/inc/config.inc.php``` (MASTER_DELETE_CODE) that, if appended to any URL of an Image, will delete the image and all cached versions of it from the server
 - Detailed traffic and view statistics of your images via [Pictshare stats](https://github.com/chrisiaut/pictshare_stats)
+- For more configuration possibilities check out the ```/inc/example.config.inc.php``` file
 
 ## Smart query system
 PictShare images can be changed after upload just by modifying the URL. It works like this:
diff --git a/inc/core.php b/inc/core.php
index 580da8b..c7675d0 100644
--- a/inc/core.php
+++ b/inc/core.php
@@ -84,7 +84,26 @@ function whatToDo($url)
     
     $data = $pm->urlToData($url);
     
-    if(!is_array($data) || !$data['hash'])
+    if(!$data['hash'] && $data['size']) //if there is only a size but no hash, generate a pattern
+    {
+        $sd = $pm->sizeStringToWidthHeight($data['size']);
+        $width = ($sd['width'] <= 2000)?$sd['width']:2000;
+        $height = ($sd['height'] <= 2000)?$sd['height']:2000;
+
+        $cachefile = ROOT.DS.'tmp'.DS.$width .'x'.$height.'.png';
+        if(!file_exists($cachefile))
+        {
+            $image=$pm->gradient($width, $height, array('#A7FF78', '#A7FF78', '#78FFD4', '#78FFD4'));
+            imagepng($image,$cachefile);
+        }
+        else 
+            $image = imagecreatefrompng($cachefile);
+        header('Content-type: image/png');
+        imagepng($image);
+        imagedestroy($image);
+        exit();
+    }
+    else if(!is_array($data) || !$data['hash'])
     {
         if((UPLOAD_FORM_LOCATION && $url==UPLOAD_FORM_LOCATION) || (!UPLOAD_FORM_LOCATION))
         {
diff --git a/models/pictsharemodel.php b/models/pictsharemodel.php
index e16aba0..cc1ae61 100644
--- a/models/pictsharemodel.php
+++ b/models/pictsharemodel.php
@@ -1042,4 +1042,63 @@ class PictshareModel extends Model
 		return array('width'=>$maxwidth,'height'=>$maxheight);
 	}
 
+
+	function gradient($w=100, $h=100, $c=array('#FFFFFF','#FF0000','#00FF00','#0000FF'), $hex=true)
+	{
+		/*
+		Generates a gradient image
+		
+		Author: Christopher Kramer
+		
+		Parameters:
+		w: width in px
+		h: height in px
+		c: color-array with 4 elements:
+			$c[0]:   top left color
+			$c[1]:   top right color
+			$c[2]:   bottom left color
+			$c[3]:   bottom right color
+			
+		if $hex is true (default), colors are hex-strings like '#FFFFFF' (NOT '#FFF')
+		if $hex is false, a color is an array of 3 elements which are the rgb-values, e.g.:
+		$c[0]=array(0,255,255);
+		
+		*/
+		
+		$im=imagecreatetruecolor($w,$h);
+		
+		if($hex) {  // convert hex-values to rgb
+		  for($i=0;$i<=3;$i++) { 
+		   $c[$i]=$this->hex2rgb($c[$i]);
+		  }
+		}
+		
+		$rgb=$c[0]; // start with top left color
+		for($x=0;$x<=$w;$x++) { // loop columns
+		  for($y=0;$y<=$h;$y++) { // loop rows
+		   // set pixel color 
+		   $col=imagecolorallocate($im,$rgb[0],$rgb[1],$rgb[2]);
+		   imagesetpixel($im,$x-1,$y-1,$col);
+		   // calculate new color  
+		   for($i=0;$i<=2;$i++) {
+			$rgb[$i]=
+			  $c[0][$i]*(($w-$x)*($h-$y)/($w*$h)) +
+			  $c[1][$i]*($x     *($h-$y)/($w*$h)) +
+			  $c[2][$i]*(($w-$x)*$y     /($w*$h)) +
+			  $c[3][$i]*($x     *$y     /($w*$h));
+		   }
+		  }
+		}
+		return $im;
+	}
+	
+	function hex2rgb($hex)
+	{
+		$rgb[0]=hexdec(substr($hex,1,2));
+		$rgb[1]=hexdec(substr($hex,3,2));
+		$rgb[2]=hexdec(substr($hex,5,2));
+		return($rgb);
+	}
+
 }
+