imageopenpolygon() is an inbuilt function in PHP that is used to draw an open polygon on a given image.
Syntax
bool imageopenpolygon(resource $image,array $points,int $num_points,int $color)
Parameters
imageopenpolygon() takes four different parameters: $image, $points, $num_points and$color.
$image − Specifies the image resource to work on.
$image − Specifies the image resource to work on.
$points − Specifies the points of the polygon.
$num_points − Specifies the number of points. The total number of (vertices) points must be at least three.
$color − This parameter specifies the color of the polygon.
Return Values
imageopenpolygon() returns True on success and False on failure.
Example 1
<?php
// Create a blank image using imagecreatetruecolor() function.
$img = imagecreatetruecolor(700, 300);
// Allocate a color for the polygon
$col_poly = imagecolorallocate($img, 0, 255, 0);
// Draw the polygon
imageopenpolygon($img, array(
0, 0,
100, 200,
400, 200
),
3,
$col_poly);
// Output the picture to the browser
header('Content-type: image/png');
imagepng($img);
imagedestroy($img);
?>Output
Example 2
<?php
// Create a blank image using imagecreatetruecolor() function.
$image = imagecreatetruecolor(700, 300);
// allocate the colors
$blue = imagecolorallocate($image, 0, 255, 255);
// Six points of the array
$points = array(
60, 130,
130, 230,
280, 230,
350, 130,
210, 30,
60, 130
);
// Create a polygon
imageopenpolygon($image, $points, 6, $blue);
// Output to the browser
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
?>Output
