Calculate the width of a string in cm

[Ballad]

Hi, I use this script below to se how different texts looks with diffrents fonts.

Now I would like to know how wide the text is, in cm if you enter the hight of the text in cm, or viseversa.

 

I have looked around alot but could´t find a sulition, but I found this forum and maybe someone can help me.

 

/Runar

 

 

 

 

   <?php
header('Content-Type: image/png');


$myImage = imagecreatefrompng($vag);

$path = '/fonts/'; 
if (!$_GET['font']) { $font = "arial"; } 
$usefont = $path . $font . '.ttf';

$rad = $_GET['text'];

$fontcolor = $_GET['fontcolor'];
$fontsize = $_GET['size'];

if (!$fontcolor) { $fontcolor = "ffffff"; } 
if (!$fontsize) { $fontsize = 40; } 

$fc1 = hexdec(substr($fontcolor,0,2));
$fc2 = hexdec(substr($fontcolor,2,2));
$fc3 = hexdec(substr($fontcolor,4,2));

$fontcolor = imagecolorallocate($myImage,$fc1,$fc2,$fc3);

            
$angle = 0;   // Angle of the text
$px = 10;     //X-koordinat were the center of the text start in the image
$y = 42.5;   //Y-koordinat were the center of the text start in the image

               
           // retrieve boundingbox
           $bbox = imagettfbbox($fontsize, $angle, $usefont, $rad);
         
           // calculate deviation
           //$dx = ($bbox[2]-$bbox[0])/2.0 - ($bbox[2]-$bbox[4])/2.0;        // deviation left-right
           $dy = ($bbox[3]-$bbox[1])/2.0 + ($bbox[7]-$bbox[1])/2.0;        // deviation top-bottom
           
           // new pivotpoint
           //$px = $x-$dx;
           $py = $y-$dy;


                
          //Text Rad 
          $res = imagesx($myImage);
          $txtsize = imagettfbbox($fontsize,0,$usefont,$rad);
          $txtwidth = abs($txtsize[2]) + abs($txtsize[0]);
          $txt_x = ($res / 2) - ($txtwidth / 2);

         imagettftext($myImage, 40, $angle, $px, $py, $fontcolor, $usefont, $rad);
        
        
        
imagepng($myImage);
imagedestroy($myImage);
?>
      

[Orio]

In different screen resolutions the length in cm will change so there's nothing you can do...

 

Orio.

[cooldude832]

what you could do is measure it in pixels and then use some basic math to convert n pixels to x where x is a result in metric assuming you can do those conversion for all screen res out there.  I am pretty sure php can pick up screen resolution

[utexas_pjm]

PHP can not know the screen resolution as the client's screen resolution is not sent in with the HTTP request header.  You might be able to pass it in via javascript though (shrug).

 

Best,

 

Patrick