<?PHP
error_reporting(E_ALL ^ E_NOTICE);
/*
btn.php
Outputs a glossy button PNG based on text & color inputs & button state
*/
// set some global parameters where they are easy to change
$font_sz = 12;
$font = 'luxisr.ttf' ; // local ttfs were trouble, so use an X11 font
$text_top = 8 ; // Distance in pixels from top the text should start
$min_cap = 32 ; // The minimum width of text area
// validate the user input
$bg = hex2int(validHexColor($_REQUEST['bg'],'ffffff'));
$fg = hex2int(validHexColor($_REQUEST['fg'],'000000'));
$string = safeString($_REQUEST['string']) ;
// if button is in "down" state, move 2 pixels down & right
$offset = ($_REQUEST['state'] === 'down') ? 2 : 0 ;
// open button body image & calculate height & initial width
$btn_body = imageCreateFromPNG('btn_body.png');
$btn_ht = imagesy($btn_body);
$start_wd = imagesx($btn_body);
$cap_wd = $start_wd/2;
// Recolor button body based upon user input
// from the number of colors, calculate distance between each color step
$colorSteps = imageColorsTotal($btn_body) - 2 ; // don't count transparency
$step['r'] = ($fg['r'] - $bg['r']) / $colorSteps ;
$step['g'] = ($fg['g'] - $bg['g']) / $colorSteps ;
$step['b'] = ($fg['b'] - $bg['b']) / $colorSteps ;
// for each index in the palette starting with white,
// set color to new calculated value
for ($n=$colorSteps;$n>=0;--$n)
imageColorSet($btn_body,$n,
round(($n * $step['r']) + $bg['r']),
round(($n * $step['g']) + $bg['g']),
round(($n * $step['b']) + $bg['b'])
) ;
// calculate the width of the text block
$tbb = imageFTBBox ($font_sz, 0, $font, $string, array());
$text_wd = $tbb[4] - $tbb[0]; // image width
// use text width to calculate final button width & x,y
$btn_wd = $start_wd + max(0,$text_wd - $min_cap) ;
$x = (($btn_wd - $text_wd) / 2) ;
$y = $font_sz + $text_top ;
// Create final button image & allocate foreground & background
$btn_out = imageCreateTrueColor($btn_wd,34);
$bgColor = imageColorAllocate($btn_out,$bg['r'],$bg['g'],$bg['b']);
$fgColor = imageColorAllocate($btn_out,$fg['r'],$fg['g'],$fg['b']);
imageFill($btn_out,0,0,$bgColor); // this isn't automatic w/ imageCreateTrueColor
// if the button is not in a down state, first draw the shadow beneath all else
if ($offset == 0) {
$btn_shadow = imageCreateFromPNG('btn_shadow.png');
// draw middle of image stretching to accomodate longer text
imageCopyResampled ($btn_out, $btn_shadow, $cap_wd, 0, $cap_wd, 0, $btn_wd-($cap_wd*2), $btn_ht, 5, $btn_ht) ;
// copy left & right sides "caps"
imageCopy($btn_out, $btn_shadow, 0, 0, 0, 0, $cap_wd, $btn_ht) ;
imageCopy($btn_out, $btn_shadow, $btn_wd - $cap_wd, 0, $cap_wd, 0, $cap_wd, $btn_ht) ;
// done with shadow, so destroy it
imageDestroy($btn_shadow);
}
// Then add the main body of the recolored button
// draw middle of image stretching to accomodate longer text
imageCopyResampled ($btn_out, $btn_body, ($cap_wd + $offset), $offset, $cap_wd, 0, $btn_wd-($cap_wd*2), $btn_ht, 5, $btn_ht) ;
// copy left & right sides "caps"
imageCopy($btn_out, $btn_body, $offset, $offset, 0, 0, $cap_wd, $btn_ht) ;
imageCopy($btn_out, $btn_body, ($btn_wd - $cap_wd + $offset), $offset, $cap_wd, 0, $cap_wd, $btn_ht) ;
// done with shadow, so destroy it
imageDestroy($btn_body);
// Add the text offset by a pixel colored in the foreground to act as highlight
$tbb = imageFTText ($btn_out, $font_sz, 0, ($x+$offset-1), ($y+$offset+1), $fgColor, $font, "$string", array());
// Next add the highlight layer, whitening anything beneath it
$btn_highlight = imageCreateFromPNG('btn_highlight.png');
// draw middle of image stretching to accomodate longer text
imageCopyResampled ($btn_out, $btn_highlight, ($cap_wd + $offset), $offset, $cap_wd, 0, $btn_wd-($cap_wd*2), $btn_ht, 5, $btn_ht) ;
// copy left & right sides "caps"
imageCopy($btn_out, $btn_highlight, $offset, $offset, 0, 0, $cap_wd, $btn_ht) ;
imageCopy($btn_out, $btn_highlight, ($btn_wd - $cap_wd + $offset), $offset, $cap_wd, 0, $cap_wd, $btn_ht) ;
// done with highlight, so destroy it
imageDestroy($btn_highlight);
// Finally add the text again, not offset, in the background color
$tbb = imageFTText ($btn_out, $font_sz, 0, ($x+$offset), ($y+$offset), $bgColor, $font, "$string", array());
// send headers, output & destroy
header("Content-type: image/png");
imagePNG($btn_out);
imageDestroy($btn_out);
/**
* @param $hex string 6-digit hexadecimal color
* @return array 3 elements 'r', 'g', & 'b' = int color values
* @desc Converts a 6 digit hexadecimal number into an array of
* 3 integer values ('r' => red value, 'g' => green, 'b' => blue)
*/
function hex2int($hex) {
return array(
'r' => hexdec(substr($hex, 0, 2)), // 1st pair of digits
'g' => hexdec(substr($hex, 2, 2)), // 2nd pair
'b' => hexdec(substr($hex, 4, 2)) // 3rd pair
);
}
/**
* @param $input string 6-digit hexadecimal string to be validated
* @param $default string default color to be returned if $input isn't valid
* @return string the validated 6-digit hexadecimal color
* @desc returns $input if it is a valid hexadecimal color,
* otherwise returns $default (which defaults to black)
*/
function validHexColor($input = '000000', $default = '000000') {
// A valid Hexadecimal color is exactly 6 characters long
// and eigher a digit or letter from a to f
return (eregi('^[0-9a-f]{6}$', $input)) ? $input : $default ;
}
function safeString($input) {
return (isset($input))?stripslashes($input):'Button';
}
?>
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