make_button.php

《PHP和MySQL Web开发》(第三版) Source

<?php
// check we have the appropriate variable data 
// variables are button-text and color

$button_text = $_REQUEST['button_text'];
$color = $_REQUEST['color'];

if (empty($button_text) || empty($color))
{
  echo 'Could not create image - form not filled out correctly';
  exit;
}

// create an image of the right background and check size
$im = ImageCreateFromPNG ($color.'-button.png');

$width_image = ImageSX($im);
$height_image = ImageSY($im);

// Our images need an 18 pixel margin in from the edge of the image
$width_image_wo_margins = $width_image - (2 * 18);
$height_image_wo_margins = $height_image - (2 * 18);

// Work out if the font size will fit and make it smaller until it does 
// Start out with the biggest size that will reasonably fit on our buttons
$font_size = 33;

// you need to tell GD2 where your fonts reside
putenv('GDFONTPATH=C:\WINDOWS\Fonts');
$fontname = 'arial';

do
{
  $font_size--;

  // find out the size of the text at that font size
  $bbox=ImageTTFBBox ($font_size, 0, $fontname, $button_text);

  $right_text = $bbox[2];   // right co-ordinate
  $left_text = $bbox[0];    // left co-ordinate
  $width_text = $right_text - $left_text;  // how wide is it?
  $height_text = abs($bbox[7] - $bbox[1]);  // how tall is it?
   
} 
while ( $font_size>8 &&
       ( $height_text>$height_image_wo_margins ||
         $width_text>$width_image_wo_margins )
      );

if ( $height_text>$height_image_wo_margins ||
     $width_text>$width_image_wo_margins ) 
{
  // no readable font size will fit on button
  echo 'Text given will not fit on button.<br />';
}
else
{
  // We have found a font size that will fit
  // Now work out where to put it

  $text_x = $width_image/2.0 - $width_text/2.0;
  $text_y = $height_image/2.0 - $height_text/2.0 ;

  if ($left_text < 0)
      $text_x += abs($left_text);    // add factor for left overhang

  $above_line_text = abs($bbox[7]);   // how far above the baseline?
  $text_y += $above_line_text;        // add baseline factor 
  
  $text_y -= 2;  // adjustment factor for shape of our template

  $white = ImageColorAllocate ($im, 255, 255, 255);

  ImageTTFText ($im, $font_size, 0, $text_x, $text_y, $white, $fontname,
                $button_text);

  Header ('Content-type: image/png');
  ImagePNG ($im);
}

ImageDestroy ($im);
?>