PHP: imagettfbbox

User Contributed Notes
imagettfbbox

php@da dot mcbf dot net
30-Apr-2005 09:37


Pretty trivial, but still might save someone some trouble: on my system (Debian Linux), the absolute path to the font file had to be specified. I tried it relative to the current webpage and that did not work.

vegard at I dot DONT dot WANT dot SPAM dot programmer dot no
04-Apr-2005 08:37


Here is a function that wordwraps text you want to print, allows to specify where the text should be printed, what the maximum width should be, and returns the height used.



<?php

        function printWordWrapped(&$image, $top, $left, $maxWidth, $font, $color, $text, $textSize) {

                $words = explode(' ', strip_tags($text)); // split the text into an array of single words

                $line = '';

                while (count($words) > 0) {

                        $dimensions = imagettfbbox($textSize, 0, $font, $line.' '.$words[0]);

                        $lineWidth = $dimensions[2] - $dimensions[0]; // get the length of this line, if the word is to be included

                        if ($lineWidth > $maxWidth) { // if this makes the text wider that anticipated

                                $lines[] = $line; // add the line to the others

                                $line = ''; // empty it (the word will be added outside the loop)

                                }

                        $line .= ' '.$words[0]; // add the word to the current sentence

                        $words = array_slice($words, 1); // remove the word from the array

                        }

                if ($line != '') { $lines[] = $line; } // add the last line to the others, if it isn't empty

                $lineHeight = $dimensions[1] - $dimensions[7]; // the height of a single line

                $height = count($lines) * $lineHeight; // the height of all the lines total

                // do the actual printing

                $i = 0;

                foreach ($lines as $line) {

                        imagettftext($image, $textSize, 0, $left, $top + $lineHeight * $i, $color, $font, $line);

                        $i++;

                        }

                return $height;

                }



?>

ryan at retronetworks dot com
28-Mar-2005 09:46


Here is a function that lets you write a string with your own "font tracking" level (the amount of pixels separating each character).  It uses imagettfbbox to determine the width of each character, so it doesn't discriminate against the skinnier of characters.  For this example, let $t = the amount of distance in pixels you want to separate each character from its neighbors.



<?php

function ImageTTFTextWithTracking($im, $size, $angle, $t, $x, $y, $color, $font, $text) {

    $numchar = strlen($text);

    for($i = 0; $i < $numchar; $i++) {

        # Assign character

        $char[$i] = substr($text, $i, 1);



        # Write character

        imagettftext($im, $size, $angle, ($x + $w + ($i * $t)), $y, $color, $font, $char[$i]);

        

        # Get width of character

        $width = imagettfbbox($size, $angle, $font, $char[$i]);

        $w = $w + $width[2];

    }

}

?>



Be aware that it currently does not work for angles other than the 0 default (I have no need for that).

soukhinov at mail dot ru
15-Mar-2005 06:00


I have tryed all of fixes

The David Eder's fix is the only working fix.

The "jtopland at hive dot no"s fix is good enough, but it not working with angle = 180 degrees.

webmaster at funfragforce dot de
10-Mar-2005 08:50


Here a little code snippet to align the text to horizontally center:



<?php

$insert = imagecreatefromgif("test.gif"); 

$text="TEST";

$font="arial.ttf";



//choose textcolor (black)

$col=ImageColorAllocate ($insert, 0, 0, 0);



//check width of the text

$bbox=imagettfbbox (12, 0, $font, $text);

$xcorr=0-$bbox[6];

$mase=$bbox[2]+$xcorr;



//check width of the image

$width=imagesx($insert);



//calculate x coordinates for text

$new=($width-$mase)/2;



//write text

imagettftext ($insert, 12, 0, $new, 50, $col, $font, $text);



//output picture

imagegif($insert,"",100); 



?>

helloktk at naver dot com
24-Jun-2004 08:55


Here is a function which moves the center of text's bounding 

box to a given pivot point (px,py) and rotates text about

that point.

<?php

$width=500;

$height=400;

$fontpath = 'c:/windows/fonts/arial.ttf';

$text = 'Finally, I have a roated text box';

$fontsize = 20;

$angle = 30.0;

// create an image and fill the background with lightgray

$image = imagecreatetruecolor($width,$height);

imagefill($image, 0, 0, 0xDDDDDD);

// bounding box

$bbox = imagettfbbox($fontsize, 0, $fontpath, $text);

// baseline point for drawing non-rotated text.

$x0=  $bbox[6];

$y0=-$bbox[7];

// fixes bounding box w.r.t. image coordinate.

$bbox[5]=-$bbox[5]+$bbox[1];

$bbox[7]=-$bbox[7]+$bbox[3];

$bbox[1]=0;

$bbox[3]=0;

// get the size of image.

$sx=imagesx($image);

$sy=imagesy($image);

// center of bounding box (xc,yc);

$xc=($bbox[0]+$bbox[2])/2.0;

$yc=($bbox[1]+$bbox[7])/2.0;

// rotation angle in radian

$rad=$angle*pi()/180.0;

$sa=sin($rad);

$ca=cos($rad);

$x1=$x0-$xc;

$y1=$y0-$yc;

//pivot point(here, we take the center of image)

$px=$sx/2.0;

$py=$sy/2.0;

// new baseline point for rotated text.

$x2= intval( $x1*$ca+$y1*$sa+$px+0.5);

$y2= intval(-$x1*$sa+$y1*$ca+$py+0.5);



imagettftext($image,$fontsize,$angle,$x2,$y2,0xFF,$fontpath,$text);

// draw rotated bounding box;

rotbbox($bbox,$angle,$px,$py);   

for($i=0;$i<4;$i++){

   $x0=$bbox[2*$i+0];

   $y0=$bbox[2*$i+1];

   $j=$i+1; 

   if($j==4) $j=0;

   $x1=$bbox[2*$j+0];

   $y1=$bbox[2*$j+1];

   imageline($image,$x0,$y0,$x1,$y1,0xFF0000);

}

// Show the image

imagepng($image);



function rotbbox(&$bbox,$angle,$px,$py){

     $xc=($bbox[0]+$bbox[2])/2.0;

     $yc=($bbox[1]+$bbox[7])/2.0;

     $rad=$angle*pi()/180.0;

     $sa=sin($rad);

     $ca=cos($rad);

     for ($i=0;$i<4;$i++){

         $x=$bbox[$i*2+0]-$xc;

         $y=$bbox[$i*2+1]-$yc;

         $bbox[$i*2+0]= intval( $ca*$x+$sa*$y+$px+0.5);

         $bbox[$i*2+1]= intval(-$sa*$x+$ca*$y+$py+0.5);

     }

}

?>

jrisken at mn dot rr dot com
09-Mar-2004 04:12


I took Magicaltux's word wrap procedure and modified it in two ways.  I changed the order of processing so that the string plotting function is called only once for each word instead of for every character.  And I wrote the results to a string scalar instead of a string array, with embedded breaks <br> at line ends.  It should run pretty fast.  Mine breaks only on spaces, but hyphens could easily be added.



I'm new to PHP so I apologize for my idiosyncratic formatting conventions.

<?

function myWordWrap($txt,$font,$size,$width) 

{

    /*

        word-wrapper.  gets bounding box sizes for each word in a string, then

        strings words together up to desired width. calls strpos and

        imagettfbbox only once per word - so very fast.

        this version reconcatenates the words with a <br> character where

        the line break should be.

    */

    $txt.=" "; // guaranteed to find end of line

    $spaces=array();

    $wids=array();

    $i=0;

    while(true)

    {

        $j=strpos(substr($txt,$i)," ");

        if(!($j===false))

        {

            $spaces[]=$j+$i;

            $bbox=imagettfbbox($size,0,$font,substr($txt,$i,$j+1));

            $left=($bbox[0]>$bbox[6])?$bbox[6]:$bbox[0]; 

            $right=($bbox[2]>$bbox[4])?$bbox[2]:$bbox[4]; 

            $wids[]=$right-$left; 

            $i=$j+$i+1;

        }

        else     break;

    }

    $lastspace=-1;

    $cum=0;

    $t2="";

    for($i=0;$i<count($spaces);$i++)

    {

        if((($cum>0)&&($cum+$wids[$i])>$width)) // time for a line break

        {

            $t2.="<br>";

            $cum=0;

            $i--;

        }

        else 

        {

            // we'll always get at least one word (even if too wide) thanks to 

            // ($cum>0) test above

            $t2.=substr($txt,$lastspace+1,$spaces[$i]-$lastspace);

            $cum+=$wids[$i];

            $lastspace=$spaces[$i];

        }

    }

    return $t2;

}

?>

LB
11-Feb-2004 09:55


the oliver dot martin at onemail dot fixbbox function is just lacking a small thing:

the coordonates for top and left have to be the opposite, because the imagettftext x and y coordonates are calculated from the top left of the image and set the bottom left of the first character.



The correct function is:

function fixbbox($bbox)

{

  $tmp_bbox["left"] = min($bbox[0],$bbox[2],$bbox[4],$bbox[6]);

  $tmp_bbox["top"] = min($bbox[1],$bbox[3],$bbox[5],$bbox[7]);

  $tmp_bbox["width"] = max($bbox[0],$bbox[2],$bbox[4],$bbox[6]) -

    min($bbox[0],$bbox[2],$bbox[4],$bbox[6]) + 1;

  $tmp_bbox["height"] = max($bbox[1],$bbox[3],$bbox[5],$bbox[7]) - min($bbox[1],$bbox[3],$bbox[5],$bbox[7]);



  $tmp_bbox["left"] = 0 - $tmp_bbox["left"];

  $tmp_bbox["top"] = 0 - $tmp_bbox["top"];

  return $tmp_bbox;

}



And it works for any rotated text.

David Eder
10-Feb-2004 11:46


As "oliver dot martin at onemail dot at" noted above, imagettfbbox() does not work correctly in php 4.3.4.  To remedy this, I've written a short function that uses trig to calculate the bounding box from rotating a non-rotated piece of text.



Hopefully, this comment will be obsolete soon, but for now, ...



function imagettfbbox_t($size, $angle, $fontfile, $text)

{

  // compute size with a zero angle

  $coords = imagettfbbox($size, 0, $fontfile, $text);



  // convert angle to radians

  $a = $angle * M_PI / 180;



  // compute some usefull values

  $ca = cos($a);

  $sa = sin($a);

  $ret = array();



  // perform transformations

  for($i = 0; $i < 7; $i += 2)

  {

    $ret[$i] = round($coords[$i] * $ca + $coords[$i+1] * $sa);

    $ret[$i+1] = round($coords[$i+1] * $ca - $coords[$i] * $sa);

  }

  return $ret;

}

jtopland at hive dot no
08-Feb-2004 04:26


Finally managed to make a fixed version of imagettfbbox().

All angles returns correct values.

Except that imagettftext() returns different trackings (space between each character) when rotating.



<?php

    // Set some test variables

    $font = "d://www//tahoma.ttf";

    $text = "Finally, I can center rotated text!";

    $size = 20;

    $angle = 20;



    // Create an image and fill the background with lightgray

    $image = imagecreatetruecolor(500, 400);

    imagefill($image, 0, 0, hexdec("dddddd"));



    // Make a cross to make it easier to analyze

    imageline($image, 0, 0, imagesx($image), imagesy($image), hexdec("000000"));

    imageline($image, imagesx($image), 0, 0, imagesy($image), hexdec("000000"));



    // Run a fixed version of imagettfbbox()

    $bbox = imagettfbbox_fixed($size, $angle, $font, $text);



    // Make some text and center the text on the image.

    // imagettftext() pivot is on lower left

    imagettftext($image, $size, $angle, imagesx($image) / 2 - $bbox['width'] / 2, imagesy($image) / 2 + $bbox['height'] / 2, hexdec("0000ff"), $font, $text);



    // Show the image

    imagepng($image);



    function imagettfbbox_fixed($size, $angle, $font, $text)

    {

        // Get the boundingbox from imagettfbbox(), which is correct when angle is 0

        $bbox = imagettfbbox($size, 0, $font, $text);



        // Rotate the boundingbox

        $angle = pi() * 2 - $angle * pi() * 2 / 360;

        for ($i=0; $i<4; $i++)

        {

            $x = $bbox[$i * 2];

            $y = $bbox[$i * 2 + 1];

            $bbox[$i * 2] = cos($angle) * $x - sin($angle) * $y;

            $bbox[$i * 2 + 1] = sin($angle) * $x + cos($angle) * $y;

        }



        // Variables which tells the correct width and height

        $bbox['width'] = $bbox[0] + $bbox[4];

        $bbox['height'] = $bbox[1] - $bbox[5];



        return $bbox;

    }

?>

oliver dot martin at onemail dot at
09-Jan-2004 03:13


The original fixbox function by <php at deathz0rz dot homeunix dot net> doesn't work when the text is rotated, as it assumes that the upper left corner of the text is also the upper left corner of the bounding box. Same goes for the lower right corner. Here is my corrected version of it:



<?

function fixbbox($bbox)

{

    $tmp_bbox["left"] = min($bbox[0],$bbox[2],$bbox[4],$bbox[6]);

    $tmp_bbox["top"] = min($bbox[1],$bbox[3],$bbox[5],$bbox[7]);

    $tmp_bbox["width"] = max($bbox[0],$bbox[2],$bbox[4],$bbox[6]) - min($bbox[0],$bbox[2],$bbox[4],$bbox[6]);

    $tmp_bbox["height"] = max($bbox[1],$bbox[3],$bbox[5],$bbox[7]) - min($bbox[1],$bbox[3],$bbox[5],$bbox[7]);

    

    return $tmp_bbox;

}

?>



However, be aware that this might not be very useful, as gd-2.0.8 introduces a bug which renders the results of imagettfbbox() useless when the text is rotated. This is still not fixed in the the php-4.3.4 bundled version (2.0.15 compatible).

MagicalTux at FF.ST
22-Dec-2003 02:09


One use of this function is to do some WordWrap =p



I wrote a little function to make a basic wordwrap : it returns an array with each line in a row.



You just have to display each row on a different line (calling many times imagettftext) to get a good result.

The character ^ is assumed as a linebreak.



<?php



function im_wordwrap($txt,$font,$size,$width) {

    $sep=array(' ','-'); // separators

    $res=array();

    $buf='';

    // main function loop

    for($i=0;$i<strlen($txt);$i++) {

        $l=$txt{$i};

        if ($l=='^') {

            $res[]=$buf;

            $buf='';

            continue;

        }

        $t=$buf.$l;

        $bbox=imagettfbbox($size,0,$font,$t);

        $left=($bbox[0]>$bbox[6])?$bbox[6]:$bbox[0]; // determine most far points

        $right=($bbox[2]>$bbox[4])?$bbox[2]:$bbox[4]; // idem

        $w=$right-$left; // get total width

        if ($w>$width) {

            if ($buf=='') return false; // FATAL: 1 letter is smallest than the pixel width - avoid infinite loop

            // we can assume that everything present in $buf currently is inside our limits

            // find a separator in string

            $fp=false;

            foreach($sep as $s) {

                $p=strrpos($buf,$s);

                if (($p!==false) and ($p>$fp)) $fp=$p;

            }

            if ($fp===false) {

                // let's break here !

                $res[]=$buf;

                $buf='';

                $i--; // dececrase $i to retry this letter

                continue;

            }

            // $fp+1 -> we put the separator char at the end of the prev. line =p

            $res[]=substr($buf,0,$fp+1);

            $buf=substr($buf,$fp+1);

            $i--;

            continue;

        }

        $buf.=$l;

    }

    if ($buf!='') $res[]=$buf;

    return $res;

}

?>

php at deathz0rz dot homeunix dot net
14-Dec-2003 08:38


The array this function returns is very strange, at least, i think so... So i created this function that 'fixes' the bounding box array into some human-understandable format



<?php

function fixbbox($bbox)

{

    $xcorr=0-$bbox[6]; //northwest X

    $ycorr=0-$bbox[7]; //northwest Y

    $tmp_bbox['left']=$bbox[6]+$xcorr;

    $tmp_bbox['top']=$bbox[7]+$ycorr;

    $tmp_bbox['width']=$bbox[2]+$xcorr;

    $tmp_bbox['height']=$bbox[3]+$ycorr;

    

    return $tmp_bbox;

}

?>

Brian at NOSPAM at PrintsMadeEasy dot com
04-Sep-2002 03:12


There seems to be a little confusion regarding the font coordinate system.  PHP's TTF functions will make more sense after you understand the principals of font creation.  This guy wrote a really good overview...

http://pfaedit.sourceforge.net/overview.html

imagettfbbox

Description