gistfile1.php

<?php
// Usage: icon_letters.php?FN=symbol&L=m&L_B=250&L_R=00&L_G=150&BG_B=100&BG_R=150&BG_G=250
// Usage: icon_letters.php?FN=kaiu&dx=-3&dy=0&BG_B=100&BG_R=100&L=陈

$width_height = 320;

//Send a generated image to the browser
$LETTERS_MAX_LEN = 3;
$letters = "SDP";
if (isset($_GET['L'])) {
  $letters = $_GET['L'];
	if (strlen($letters) == 0) {
		$letters = "SDP";
	}
}
if (strlen($letters) > $LETTERS_MAX_LEN) {
	$letters = substr($letters, 0, $LETTERS_MAX_LEN);
}
# detect if the string was passed in as unicode
# make sure it's in unicode
if (mb_detect_encoding($letters, 'UTF-8, ISO-8859-1') != 'UTF-8') {
    $letters = mb_convert_encoding($letters, 'UTF-8', $text_encoding);
}
# html numerically-escape everything (&#[dec];)
$letters = mb_encode_numericentity($letters, array (0x0, 0xffff, 0, 0xffff), 'UTF-8');


$avail_fonts = array("arial", "arialb", "ariali", "cour", "courb", "georgia", "georgiab", "georgiai", "tahoma", "tahomab", "verdana", "verdanai", "verdanab", "symbol", "kaiu");
$font = "arial";
if (isset($_GET['FN'])) {
	$font = $_GET['FN'];
	if (!in_array($font, $avail_fonts)) {
		$font = "arial";
	}
}

$letter_R = 1;
if (isset($_GET['L_R'])) {
	$letter_R = intval($_GET['L_R']);
	if ($letter_R > 255) {
		$letter_R = 255;
	}
	if ($letter_R < 1) {
		$letter_R = 1;
	}
}

$letter_G = 1;
if (isset($_GET['L_G'])) {
	$letter_G = intval($_GET['L_G']);
	if ($letter_G > 255) {
		$letter_G = 255;
	}
	if ($letter_G < 1) {
		$letter_G = 1;
	}
}

$letter_B = 1;
if (isset($_GET['L_B'])) {
	$letter_B = intval($_GET['L_B']);
	if ($letter_B > 255) {
		$letter_B = 255;
	}
	if ($letter_B < 1) {
		$letter_B = 1;
	}
}




$BG_R = 255;
if (isset($_GET['BG_R'])) {
	$BG_R = intval($_GET['BG_R']);
	if ($BG_R > 255) {
		$BG_R = 255;
	}
	if ($BG_R < 0) {
		$BG_R = 0;
	}
}

$BG_G = 10;
if (isset($_GET['BG_G'])) {
	$BG_G = intval($_GET['BG_G']);
	if ($BG_G > 255) {
		$BG_G = 255;
	}
	if ($BG_G < 0) {
		$BG_G = 0;
	}
}

$BG_B = 10;
if (isset($_GET['BG_B'])) {
	$BG_B = intval($_GET['BG_B']);
	if ($BG_B > 255) {
		$BG_B = 255;
	}
	if ($BG_B < 0) {
		$BG_B = 0;
	}
}

$dx = 0;
if (isset($_GET['dx'])) {
	$dx = (int)($_GET['dx']);
}

$dy = 0;
if (isset($_GET['dy'])) {
	$dy = (int)($_GET['dy']);
}


create_image($width_height, $letters, $font, $dx, $dy, $letter_R, $letter_G, $letter_B, $BG_R, $BG_G, $BG_B);
exit();

function create_image($width_height, $letters, $font, $dx, $dy, $letter_R, $letter_G, $letter_B, $BG_R, $BG_G, $BG_B)
{
    //Set the image width and height
    $border_radius = floor($width_height/9);
    $inner_border_radius = ceil($width_height/8);
	$fontfile = "./fonts/".$font.".ttf";

    //Create the image resource
    $image = ImageCreateTrueColor($width_height, $width_height);

    //We are making three colors, white, black and gray
    $transparent = ImageColorAllocateAlpha($image, 0, 0, 0, 127);

    $letter_color = ImageColorAllocateAlpha($image, $letter_R, $letter_G, $letter_B, 15);
    $BG_color = ImageColorAllocateAlpha($image, $BG_R, $BG_G, $BG_B, 30);

	// draw corners
    filled_rounded_rect($image, 0, 0, $width_height, $width_height, $border_radius, $BG_color);

	$ok = false;
	$fontsize = $width_height - 2*$inner_border_radius;
	$text_position_x = 0;
	$text_position_y = 0;
	while (!$ok) {
		$ok = true;

		$curr_ttf_box = imagettfbbox( $fontsize, 0, $fontfile, $letters );

		// key	contents
		// 0	lower left corner, X position
		// 1	lower left corner, Y position
		// 2	lower right corner, X position
		// 3	lower right corner, Y position
		// 4	upper right corner, X position
		// 5	upper right corner, Y position
		// 6	upper left corner, X position
		// 7	upper left corner, Y position

		if ( (($curr_ttf_box[2] - $curr_ttf_box[0]) > $width_height - 2*$inner_border_radius) || (($curr_ttf_box[1] - $curr_ttf_box[7]) > $width_height - 2*$inner_border_radius) )
		{
			$ok = false;
			$fontsize = $fontsize - 1;
		}
		else
		{
			$text_position_x = floor($inner_border_radius + (($width_height - 2*$inner_border_radius)-($curr_ttf_box[2] - $curr_ttf_box[0]))/2);

			$text_position_y = floor($inner_border_radius - $curr_ttf_box[7] + (($width_height - 2*$inner_border_radius)-($curr_ttf_box[1] - $curr_ttf_box[7]))/2);

			// imageline($image, $text_position_x, $text_position_y, $text_position_x+($curr_ttf_box[2] - $curr_ttf_box[0]), $text_position_y - ($curr_ttf_box[1] - $curr_ttf_box[7]), $letter_color );
			// imageline($image, $text_position_x, $text_position_y - ($curr_ttf_box[1] - $curr_ttf_box[7]), $text_position_x+($curr_ttf_box[2] - $curr_ttf_box[0]), $text_position_y, $letter_color );
			// imageline($image, $text_position_x, $text_position_y, $text_position_x, $text_position_y - ($curr_ttf_box[1] - $curr_ttf_box[7]), $letter_color );
			// imageline($image, $text_position_x, $text_position_y, $text_position_x+($curr_ttf_box[2] - $curr_ttf_box[0]), $text_position_y, $letter_color );
			// imageline($image, $text_position_x+($curr_ttf_box[2] - $curr_ttf_box[0]), $text_position_y, $text_position_x+($curr_ttf_box[2] - $curr_ttf_box[0]), $text_position_y - ($curr_ttf_box[1] - $curr_ttf_box[7]), $letter_color );
			// imageline($image, $text_position_x, $text_position_y - ($curr_ttf_box[1] - $curr_ttf_box[7]), $text_position_x+($curr_ttf_box[2] - $curr_ttf_box[0]), $text_position_y - ($curr_ttf_box[1] - $curr_ttf_box[7]), $letter_color );

			}

	}

    //Add string to the image
	ImageTTFText($image, $fontsize, 0, $text_position_x + $dx, $text_position_y - $dy, $letter_color, $fontfile, $letters);

	ImageAlphaBlending($image, false);
	ImageSaveAlpha($image, true);

    //Tell the browser what kind of file is come in
    header("Content-Type: image/png");

    //Output the newly created image in png format
    ImagePng($image);

    //Free up resources
    ImageDestroy($image);
}

function filled_rounded_rect($image, $x0, $y0, $width, $height, $corner, $color)
{
    $x1 = $x0 + $width - 1;
    $y1 = $y0 + $height - 1;

    // Approach #1: Draws border then flood fill

    /* imagearc($image, $x0+$corner-1, $y0+$corner-1, $corner*2, $corner*2, 180, 270, $color); */
    /* imagearc($image, $x1-$corner+1, $y0+$corner-1, $corner*2, $corner*2, 270, 0, $color); */
    /* imagearc($image, $x0+$corner-1, $y1-$corner+1, $corner*2, $corner*2, 90, 180, $color); */
    /* imagearc($image, $x1-$corner+1, $y1-$corner+1, $corner*2, $corner*2, 0, 90, $color); */

    /* imageline($image, $x0+$corner, $y0, $x1-$corner, $y0, $color); */
    /* imageline($image, $x0+$corner, $y1, $x1-$corner, $y1, $color); */
    /* imageline($image, $x0, $y0+$corner, $x0, $y1-$corner, $color); */
    /* imageline($image, $x1, $y0+$corner, $x1, $y1-$corner, $color); */

    /* imagefilltoborder($image, ($x0+$x1)/2, ($y0+$y1)/2, $color, $color); */

    // Approach #2: Draws 4 filled arcs, followed by 3 filled rectangles

    imagefilledarc($image, $x0+$corner-1, $y0+$corner-1, $corner*2, $corner*2, 180, 270, $color, IMG_ARC_PIE);
    imagefilledarc($image, $x1-$corner+1, $y0+$corner-1, $corner*2, $corner*2, 270, 0, $color, IMG_ARC_PIE);
    imagefilledarc($image, $x0+$corner-1, $y1-$corner+1, $corner*2, $corner*2, 90, 180, $color, IMG_ARC_PIE);
    imagefilledarc($image, $x1-$corner+1, $y1-$corner+1, $corner*2, $corner*2, 0, 90, $color, IMG_ARC_PIE);

    imagefilledrectangle($image, $x0, $y0+$corner, $x1, $y1-$corner, $color);
    imagefilledrectangle($image, $x0+$corner-1, $y0, $x1-$corner+1, $y0+$corner-1, $color);
    imagefilledrectangle($image, $x0+$corner-1, $y1-$corner+1, $x1-$corner+1, $y1, $color);
}