php - 在多行上转换单行字符串，然后插入图像

Question

I'm programming a script that inserts a text on an image, it works but not entirely, ie if a user adds a line break in the textarea is fine, but if all the text is on one line looks bad . This is my code

$str="this is a string inserted by an user";
$img_width= 500;
$img_height= 500;
$font_size = 1; 
$txt_max_width = intval(0.6 * $img_width);
do {
    $font_size++;
    $p = imagettfbbox($font_size,0,$font,$str);
    $txt_width=$p[2]-$p[0];
    } while ($txt_width <= $txt_max_width);
    $y = $img_height * 0.4;
$x = ($img_width - $txt_width) / 2;
$white = imagecolorallocate($img, 255, 255, 255);
imagettftext($img, $font_size, 0, $x, $y, $white, $font, $str);
imagepng($img);
imagedestroy($img);

Look at this for understand http://app.xskarx.com

PS: sorry for my bad english

Answer 1

What you want to do, is to split the string into smaller block or chunks, for that, you have chunk_split in PHP.

You will use it this way:

// initialize variables
$final_string = false;
$size_of_the_chunk = 20;
$str = "_this_is_a_very_long_string__this_is_a_very_long_string__this_is_a_very_long_string__this_is_a_very_long_string__this_is_a_very_long_string__this_is_a_very_long_string_";
$length_of_string = strlen( $str );

// work only if necessary
if ( $length_of_string > $size_of_the_chunk ) {
    $final_string = chunk_split( $str, $size_of_the_chunk );
} else {
    $final_string = $str;
}

The main problem you may have, is that the string will get split on random places, at least random from the perspective of the user, and so, the fragments may not make much sense. Try to improve the user interface by informing that they should use line breaks.