无法在图像中包装文本

Question

我已经创建了一个PHP脚本，您可以在其中输入HTML输入框中的文本，然后它将生成带有背景图像和特定位置文本的图像。我发现这个代码可以将文本换成HTML，但是如何在30个字符之后创建它在图像上创建一个新行？

HTML换行符的代码是：

$dir = html_entity_decode($_POST['sig']).' ' ;  
$sig = wordwrap($dir , 30, "<br />", true);

图片代码为：

<?php   

// clean up the input
if(empty($_GET['date']))    fatal_error('Error: No text specified.') ;


$date = Date("F d, Y, h:i A", $now);
$name = html_entity_decode($_GET['pname']).' ' ;
$email = html_entity_decode($_GET['dob']).' ' ;


if(empty($date))

    fatal_error('Error: Text not properly formatted.') ;


// customizable variables
$font_file      = 'Muli-Regular.ttf';
$font_size      = 10 ; // font size in pts
$font_color     = '#000' ;
$image_file     = 'background.png';

// x and y for the bottom right of the text
// so it expands like right aligned text
$x_finalpos     = 340;
$y_finalpos     = 250;

$xpos = 180; 
$ypos = 278;

$xpos1 = 225; 
$ypos1 = 305;


$mime_type          = 'image/png' ;
$extension          = '.png' ;
$s_end_buffer_size  = 4096 ;

// check for GD support
if(!function_exists('ImageCreate'))
    fatal_error('Error: Server does not support PHP image generation') ;

// check font availability;
if(!is_readable($font_file)) {
    fatal_error('Error: The server is missing the specified font.') ;
}

// create and measure the text
$font_rgb = hex_to_rgb($font_color) ;
$box = @ImageTTFBBox($font_size,0,$font_file,$date) ;
$box1 = @ImageTTFBBox($font_size,0,$font_file,$pname) ;
$box2 = @ImageTTFBBox($font_size,0,$font_file,$dob) ;

$date_width = abs($box[2]-$box[0]);
$date_height = abs($box[5]-$box[3]);

$name_width = abs($box1[2]-$box1[0]);
$name_height = abs($box1[5]-$box1[3]);  

$email_width = abs($box2[2]-$box2[0]);
$email_height = abs($box2[5]-$box2[3]);


$medOther_width = abs($box10[2]-$box10[0]);
$medOther_height = abs($box10[5]-$box10[3]);

$image =  imagecreatefrompng($image_file);

if(!$image || !$box)
{
    fatal_error('Error: The server could not create this image.') ;
}

// allocate colors and measure final text position
$font_color = ImageColorAllocate($image,$font_rgb['red'],$font_rgb['green'],$font_rgb['blue']) ;

$image_width = imagesx($image);

$put_date_x = $image_width - ($image_width - $x_finalpos);
$put_date_y = $y_finalpos;

$put_name_x = $image_width - ($image_width - $xpos);
$put_name_y = $ypos;

$put_email_x = $image_width - ($image_width - $xpos1);
$put_email_y = $ypos1;


// Write the text
imagettftext($image, $font_size, 0, $put_date_x,  $put_date_y, $font_color, $font_file, $date);
imagettftext($image, $font_size, 0, $put_name_x,  $put_name_y, $font_color, $font_file, $name);
imagettftext($image, $font_size, 0, $put_email_x,  $put_email_y, $font_color, $font_file, $email);


header('Content-type: ' . $mime_type) ;
ImagePNG($image) ;

ImageDestroy($image) ;
exit ;


/*
    attempt to create an image containing the error message given. 
    if this works, the image is sent to the browser. if not, an error
    is logged, and passed back to the browser as a 500 code instead.
*/
function fatal_error($message)
{
    // send an image
    if(function_exists('ImageCreate'))
    {
        $width = ImageFontWidth(5) * strlen($message) + 10 ;
        $height = ImageFontHeight(5) + 10 ;
        if($image = ImageCreate($width,$height))
        {
            $background = ImageColorAllocate($image,255,255,255) ;
            $text_color = ImageColorAllocate($image,0,0,0) ;
            ImageString($image,5,5,5,$message,$text_color) ;    
            header('Content-type: image/png') ;
            ImagePNG($image) ;
            ImageDestroy($image) ;
            exit ;
        }
    }

    // send 500 code
    header("HTTP/1.0 500 Internal Server Error") ;
    print($message) ;
    exit ;
}


/* 
    decode an HTML hex-code into an array of R,G, and B values.
    accepts these formats: (case insensitive) #ffffff, ffffff, #fff, fff 
*/    
function hex_to_rgb($hex) {
    // remove '#'
    if(substr($hex,0,1) == '#')
        $hex = substr($hex,1) ;

    // expand short form ('fff') color to long form ('ffffff')
    if(strlen($hex) == 3) {
        $hex = substr($hex,0,1) . substr($hex,0,1) .
               substr($hex,1,1) . substr($hex,1,1) .
               substr($hex,2,1) . substr($hex,2,1) ;
    }

    if(strlen($hex) != 6)
        fatal_error('Error: Invalid color "'.$hex.'"') ;

    // convert from hexidecimal number systems
    $rgb['red'] = hexdec(substr($hex,0,2)) ;
    $rgb['green'] = hexdec(substr($hex,2,2)) ;
    $rgb['blue'] = hexdec(substr($hex,4,2)) ;

    return $rgb ;
}
?>

Answer 1

这很简单，试试这段代码：

<?php
header('Content-type: image/png');
$dir = html_entity_decode($_POST['sig']).' ';
$text_length = 30;
$sig = wordwrap($dir, $text_length, "<br />", true);
$fontsize = 12;
$fontfile = './arial.ttf';

$img = imagecreatetruecolor(500, 500); //there will be opened background image
$c = imagecolorallocate($img, 255, 255, 255);

//Just wrap text by newlines
$text = str_replace('<br />', "\n", $sig);
imagettftext($img, $fontsize, 0, 0, $fontsize+2, $c, $fontfile, $text); // "+2" - height of space-line

imagepng($img);
imagedestroy($img);

当然，您将更改图像的初始坐标和宽度和高度，但在此示例中，您可以看到它是如何工作的：）

Answer 2

对此的回答是manual page of imagettftext的第二条评论。具体来说，imagettftext无法识别换行符并处理它们。相反，您必须使用wordwrap将字符串拆分为行，并单独放置每一行。