The GmagickDraw::polyline() function is an inbuilt function in PHP which is used to draw a polyline using the current stroke, stroke width, and fill color or texture, using the specified array of coordinates.
Syntax:
GmagickDraw GmagickDraw::polyline( array $coordinates_array )
Parameters: This function accepts a single parameter $coordinates_array which is used to hold the coordinates of the point as an array.
Return Value: This function returns GmagickDraw object on success.
Exceptions: This function throws GmagickDrawException on error.
Used Image: 
Below examples illustrate the GmagickDraw::polyline() function in PHP:
Program 1: Drawing over an image
<?php   // Create a new Gmagick object $gmagick = new Gmagick('neveropen.png');   // Create a GmagickDraw object $draw = new GmagickDraw();   // Set the fill color $draw->setFillColor('#0E0E0E');   // Set the stroke color $draw->setstrokecolor('green');   // Set the stroke width $draw->setStrokeWidth(5);   // Create a polygonline $draw->polyline([     ['x' => 100, 'y' => 50],     ['x' => 40, 'y' => 150],     ['x' => 480, 'y' => 150],     ['x' => 110, 'y' => 75], ]);   // Use of drawimage function $gmagick->drawImage($draw);   // Display the output image header("Content-Type: image/png"); echo $gmagick->getImageBlob(); ?> |
Output:
Program 2: Drawing from scratch
<?php   // Create a new Gmagick object $gmagick = new Gmagick('neveropen.png');   // Create a GmagickDraw object $draw = new GmagickDraw();   // Draw rectangle for background $draw->rectangle(-10, -10, 800, 400);   // Set the fill color $draw->setFillColor('white');   // Set the stroke color $draw->setstrokecolor('red');   // Set the stroke width $draw->setStrokeWidth(5);   // Create a polygonline $draw->polyline([     ['x' => 400, 'y' => 0],     ['x' => 40, 'y' => 170],     ['x' => 480, 'y' => 150],     ['x' => 110, 'y' => 5], ]);   // Use of drawimage function $gmagick->drawImage($draw);   // Display the output image header("Content-Type: image/png"); echo $gmagick->getImageBlob(); ?> |
Output:
Reference: https://www.php.net/manual/en/gmagickdraw.polyline.php
