imagerectangle() creates a rectangle starting at the specified coordinates.
image
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
x1
Upper left x coordinate
y1
Upper left y coordinate 0, 0 is the top left corner of the image.
x2
Bottom right x coordinate
y2
Bottom right y coordinate
color
A color identifier created with imagecolorallocate()