GD Library - Draw Graphical Elements

This section provides a tutorial example on how to draw graphical elements using GD Library functions.

You can use GD Library functions to create a new image and draw some graphical elements.

1. Write a PHP script to create an image with some graphical elements added and save it to GD-Graphics.png:

<?php
#  GD-Create-Image.php
#- Copyright 2009 (c) HerongYang.com. All Rights Reserved.

$image = imagecreatetruecolor(400,400);

$blue = imagecolorallocate($image, 0, 0, 255);
$green = imagecolorallocate($image, 0, 255, 0);
$red = imagecolorallocate($image, 255, 0, 0);

print("Drawing a box...\n");
imagefilledrectangle($image, 50, 50, 350, 350, $blue);

print("Drawing a circle...\n");
imagefilledellipse($image, 200, 200, 200, 200, $green);

print("Drawing 2 lines...\n");
imageline($image, 0,0, 400, 400, $red);
imageline($image, 400,0, 0, 400, $red);

$file = "GD-Graphics.png";
imagepng($image, $file);
print("Image saved:\n");
print("   File: $file\n");
?>

2. Run the above script:

herong$ php GD-Create-Image.php
Drawing a box...
Drawing a circle...
Drawing 2 lines...
Image saved:
   File: GD-Graphics.png

3. View GD-Graphics.png. You see a nice image.

Table of Contents

 About This Book

 Introduction and Installation of PHP

 Managing PHP Engine and Modules on macOS

 Managing PHP Engine and Modules on CentOS

 cURL Module - Client for URL

 DOM Module - Parsing HTML Documents

GD Module - Manipulating Images and Pictures

 GD Library of Image Functions

GD Library - Draw Graphical Elements

 GD Library - Print 2 Pictures on 1 Page

 GD Library - Create Transparent Image

 Transparent Image Over Text Web Page

 GD Library - Pad Transparent Image

 MySQLi Module - Accessing MySQL Server

 OpenSSL Module - Cryptography and SSL/TLS Toolkit

 PCRE Module - Perl Compatible Regular Expressions

 SOAP Module - Creating and Calling Web Services

 SOAP Module - Server Functions and Examples

 Zip Module - Managing ZIP Archive Files

 References

 Full Version in PDF/EPUB