通过文字传递创建的图形按钮

通过文字传递创建的图形按钮,详细说明请看文内英文说明
<?php header( "content-type: image/gif"); // info for the browser
    /* php3 button generator, (c) 2000 by izzysoft (izzysoft@buntspecht.de)
    * license: gpl (and it would be nice to drop me a note that you find it
    * useful - if you use it. and, of course, i am very interested in
    * enhancements you made to the script!
    *
    * purpose: generate buttons with text passed by parameter.
    *
    * possible parameters to the script:
    *button- input gif image. just the part of the filename before the dot.
    *the specified image file is expected in the same directory
    *as this script resides in.
    *font - font to use (1 - 5; 1 is very small, 3 medium, 5 normal size.
    *the script will automatically use a smaller font if text is
    *too long for selected size.) default: 5
    *text - the text to be put on the button. will be centered.
    *textcolor - color for the letters. default: white.
    *in this example code only blue, white and black are defined;
    *but you can add custom colors easily.
    *width,heigth - width and heigth of the button. useful only if target
    *button should have different size than source image.
    *
    * example for usage:
    * <img src="button.php3?button=yellow&text=example">
    * will look for yellow.gif and put the string "example" on it.
    *
    * i use to have three buttons i normally generate (one displays selected
    * item, one is for mouseover(), and one is the default button). the source
    * images are yellow.gif, white.gif and blue.gif - so my script assumes
    * blue.gif as default if "button=" not specified - you may wish to change
    * this below, it's easy ;)
    */
    // ===========================[ check fo
    //     r parameters and/or set defaults ]===
    if (($font == "") || ($font > 5) || ($font < 1)) { $font = 5; }
    if ($text == "") { $text="moin!"; }// button text
    if ($textcolor == "") {// color for the letters
    switch ($button) {
    case "yellow":
    case "white":
    $textcolor = "black";
    break;
    default:
    if ($button == "") { $button = "blue"; }
    $textcolor = "white";
    break;
    }
    } // textcolor end
    $im_info = getimagesize("$button.gif"); // button size
    if ($width == "") {
    if ($im_info == "") {
    $buttonwidth = 125;
    } else {
    $buttonwidth = "$im_info[0]";
    }
    } else {
    $buttonwidth = $width;
    }
    if ($heigth == "") {
    if ($im_info == "") {
    $buttonheigth = 30;
    } else {
    $buttonheigth = "$im_info[1]";
    }
    } else {
    $buttonheigth = $heigth;
    }
    $vmidth = ceil($buttonheigth / 2);
    // =====================================
    //     ===[ now lets define some colors ]===

    $white = "255,255,255";
    $black = "0,0,0";
    $blue = "0x2c,0c6d,0xaf";
    // =====================================
    //     =============[ build color array ]===
    // now we put the needed color into an a
    //     rray (if e.g. "$textcolor=white",
    // the array $textcolor_array represents
    //     "white")
    $textcolor_array = explode(",", $$textcolor);
    // =======================[ calculate po
    //     sition of the text on the button ]===
    do {
    $textwidth = strlen($text) * imagefontwidth($font);
    $x = ($buttonwidth - $textwidth) / 2; $x = ceil($x);
    $y = $vmidth - (imagefontheight($font) / 2);
    $font--;
    } while (($x < 0) && ($font > 0)); $font++;
    // =====================================
    //     ======[ now we create the button ]===
    if (isset($width) || isset($heigth)) {// size change expected?
    $ima = imagecreatefromgif("$button.gif");// open input gif
    $im = imagecreate($buttonwidth,$buttonheigth); // create img in desired size
    $uglybg = imagecolorallocate($im,0xf4,0xb2,0xe5);
    imagerectangle($im,0,0,$buttonwidth,$buttonheigth,$uglybg);
    $dummy = imagecopyresized($im,$ima,0,0,0,0,$buttonwidth,$buttonheigth,$im_info[0],$im_info[1]);
    if ($dummy == "") {
    imagedestroy($im); // if it didn't work, create default below instead
    } else {;}
    imagedestroy($ima);
    imagecolortransparent($im,$uglybg);
    } else {
    $im = imagecreatefromgif("$button.gif");// open input gif
    }
    if ($im == "") { $im = imagecreate($buttonwidth,$buttonheigth); // if input gif not found,
    $rblue = imagecolorallocate($im, 0x2c,0x6d,0xaf);// create a default box
    imagerectangle($im,0,0,200,100,$rblue);
    }
    $color = imagecolorallocate($im, $textcolor_array[0], $textcolor_array[1], $textcolor_array[2]); // allocate the color
    imagestring($im, $font, $x, $y, "$text", $color); // put the text on it
    imagegif($im);// send button to browser
    imagedestroy($im);// free the used memory
    ?>