Page 552 - Beginning PHP 5.3

Part III: Using PHP in Practice
Next the script calls the imageline() function to draw the line. The first argument is the image
resource. The next two arguments tell the imageline() function where the line starts — in this
example, 15 pixels across and 35 pixels down from the top-left corner. The next two parameters then
tell the function where the line should end — 120 pixels across and 60 pixels down in the example.
The last parameter is, of course, the color in which to draw the line.

After the image is drawn, the script calls the header() and imagepng() functions to output the
image to the Web browser. Finally, the image is removed from memory by calling the
imagedestroy() function.

Drawing Rectangles
To draw a rectangle you only need to specify two positions on the canvas: the two opposite corners of
your rectangle. Because of this, the syntax for the imagerectangle() function is exactly the same as the
imageline() function. In the case of imagerectangle() , the two coordinates you provide are used as
opposite corners of the rectangle.
To try this out, open the line.php file that you just created and save it as rectangle.php . Replace
the line:

imageline( $myImage, 15, 35, 120, 60, $myBlack );
with the line:

imagerectangle( $myImage, 15, 35, 120, 60, $myBlack );

As you can see, the arguments passed to the imagerectangle() function are exactly the same as those
used in the line - drawing example. Save the file as rectangle.php and open the script ’ s URL in your
Web browser. Figure 17 - 6 shows the image generated by this code.

Figure 17-6
If you left the imageline() call in the code as well, you ’ d get the output shown in Figure 17 - 7.

Figure 17-7
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