Add Watermark

src/Pkcs11Command.php

@@ -447,7 +447,7 @@ class Pkcs11Command
                 throw new \Exception('Failed to decrypt PDF content.');
             }
 
-            $fpdi = new Fpdi();
+            $fpdi = new MyPdf();
 
             // Write decrypted bytes to a memory stream
             $pdfStream = fopen('php://memory', 'r+');
@@ -465,6 +465,24 @@ class Pkcs11Command
                 $fpdi->AddPage($orientation, [$size['width'], $size['height']]);
                 $fpdi->useTemplate($tplIdx);
 
+                // Set watermark style
+                $fpdi->SetFont('Helvetica', '', 10);
+                // $fpdi->SetTextColor(200, 200, 200); // light gray
+                $fpdi->SetTextColor(245, 245, 245);
+
+                // Create loop stripes across page
+                $watermarkText = auth()->user()->name . "|" . date("d/m/y") . "|" . date("h:i:s A");
+                $angle = 45; // diagonal
+                $spacing = 80; // distance between stripes
+
+                // Loop and place watermark repeatedly
+                for ($x = -50; $x < $size['width'] + 200; $x += $spacing) {
+                    for ($y = 0; $y < $size['height'] + 200; $y += $spacing) {
+                        $fpdi->Rotate($angle, $x, $y);
+                        $fpdi->Text($x, $y, $watermarkText);
+                        $fpdi->Rotate(0); // reset rotation
+                    }
+                }
             }
 
             // Output to string (S = string)
@@ -491,3 +509,35 @@ class Pkcs11Command
         }
     }
 }
+
+class MyPdf extends Fpdi {
+    protected $angle = 0;
+
+    function Rotate($angle, $x = -1, $y = -1) {
+        if ($x == -1) $x = $this->x;
+        if ($y == -1) $y = $this->y;
+        if ($this->angle != 0) {
+            $this->_out('Q');
+        }
+        $this->angle = $angle;
+        if ($angle != 0) {
+            $angle *= M_PI/180;
+            $c = cos($angle);
+            $s = sin($angle);
+            $cx = $x * $this->k;
+            $cy = ($this->h - $y) * $this->k;
+            $this->_out(sprintf(
+                'q %.5f %.5f %.5f %.5f %.5f %.5f cm 1 0 0 1 %.5f %.5f cm',
+                $c, $s, -$s, $c, $cx, $cy, -$cx, -$cy
+            ));
+        }
+    }
+
+    function _endpage() {
+        if ($this->angle != 0) {
+            $this->angle = 0;
+            $this->_out('Q');
+        }
+        parent::_endpage();
+    }
+}