imageftbbox

(PHP 4 >= 4.0.7, PHP 5, PHP 7, PHP 8)

imageftbbox — 给出一个使用 FreeType 2 字体的文本框

说明

imageftbbox ( float $size , float $angle , string $fontfile , string $text , array $extrainfo = ? ) : array

This function calculates and returns the bounding box in pixels for a FreeType text.

参数

size

字体的尺寸，单位：点（磅）。

angle

Angle in degrees in which text will be measured.

fontfile

The name of the TrueType font file (can be a URL). Depending on which version of the GD library that PHP is using, it may attempt to search for files that do not begin with a leading '/' by appending '.ttf' to the filename and searching along a library-defined font path.

text

The string to be measured.

extrainfo

**Possible array indexes for `extrainfo`**
Key	Type	Meaning
`linespacing`	float	Defines drawing linespacing

返回值

imageftbbox() returns an array with 8 elements representing four points making the bounding box of the text:

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

The points are relative to the text regardless of the angle, so "upper left" means in the top left-hand corner seeing the text horizontally.

范例

Example #1 imageftbbox() example


<?php
// Create a 300x150 image
$im = imagecreatetruecolor(300, 150);
$black = imagecolorallocate($im, 0, 0, 0);
$white = imagecolorallocate($im, 255, 255, 255);

// Set the background to be white
imagefilledrectangle($im, 0, 0, 299, 299, $white);

// Path to our font file
$font = './arial.ttf';

// First we create our bounding box
$bbox = imageftbbox(10, 0, $font, 'The PHP Documentation Group');

// This is our cordinates for X and Y
$x = $bbox[0] + (imagesx($im) / 2) - ($bbox[4] / 2) - 5;
$y = $bbox[1] + (imagesy($im) / 2) - ($bbox[5] / 2) - 5;

imagefttext($im, 10, 0, $x, $y, $black, $font, 'The PHP Documentation Group');

// Output to browser
header('Content-Type: image/png');

imagepng($im);
imagedestroy($im);
?>

注释

Note: 此函数仅在 PHP 编译时加入 freetype 支持时有效（--with-freetype-dir=DIR）。

更新日志

版本	说明
4.3.5	`extrainfo` was made optional.

User Contributed Notes

pablocorezzola at gmail dot com 15-Jun-2017 03:23


//EXAMPLE - Center text



function newText($im, $size, $angle= 0, $x, $y, $color, $font, $text,$align = "left",$border=false,$width=0,$height=0){

    

    if($align == "center")

    {

        if ($border == true ){

           imagerectangle($im, $x, $y, $x +$width, $y + $height, $color);

        }

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



        // Marcamos el ancho y alto

        $s_width  = $bbox[4];

        $s_height = $bbox[5];  

        

        $y = $y + ($height-$s_height)/2;

        $x = $x + ($width-$s_width)/2;



    }

     

    imagettftext($im, $size, $angle, $x, $y, $color, $font, $text);

}

Johan 19-Nov-2007 07:38


For alignment i used this method:



if($align == "center" || $align == "right")

    {

        $verticaltxtspace = $backwidth - (2 * $posx);        

        $spacepositions = imagettfbbox($size, $angle, "fonts/verdanaz.ttf", " ");         

        $spacepx = $spacepositions[4] - $spacepositions[0];        

        

        // Split text in lines

        $lines = split("[\r][\n]", $text);        

        for($count = 0; $count < count($lines); $count++)

        {

            $textpositions = imagettfbbox($size, $angle, "fonts/verdanaz.ttf", $lines[$count]);            

            $textpx = $textpositions[2] - $textpositions[0];

            

            if($align == "right")

            {

                $spaces = ($verticaltxtspace - $textpx) / $spacepx;

            }

            else if($align == "center")

            {

                $spaces = (($verticaltxtspace - $textpx)/2) / $spacepx;

            }

            

            // Add spaces

            $line = $lines[$count];

            for($i = 0; $i < $spaces; $i++)

            {

                $line = " " . $line;

            }

            $lines[$count] = $line;

        }

        

        // Create new text of lines

        $text = "";

        for($count = 0; $count < count($lines); $count++)

        {

            $text .= $lines[$count] . "\r\n";

        }        

    }

    

        

    //    Draw the shadow text on de shadow

    imagettftext($background, $size, $angle, $posx, $posy, $textcolor, "fonts/verdanaz.ttf",  $text);

theo v e -2 28-Dec-2005 07:10


ah... the problem between imageftbbox() and imagefttext() lies in the mirroring of the y-axes.

Below you see, for a font-size 16 the boudingboxes of "b", "p" and "bp":

< b: w=9 h=15

b(0,-1)

b(9,-1)

b(9,-16)

b(0,-16)

< p: w=9 h=16

p(0,4)

p(9,4)

p(9,-12)

p(0,-12)

< bp: w=20 h=20

bp(0,4)

bp(20,4)

bp(20,-16)

bp(0,-16)

If drawing "bp" using imagefttext() at y=0, the the top of "bp" indeed is at y=-16, and the bottom of "bp" at y=4. (Plus or minus a pixel here and there, because at y=0 there actually is a vissible pixel.)

fernando 14-Jul-2005 01:20


imagettfbbox() returns an array with 8 elements representing four points making the bounding box of the text: 



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 



The points are relative to the text regardless of the angle, so "upper left" means in the top left-hand corner seeing the text horizontally.

groomed at users dot sf dot net 27-May-2004 12:38


ImageFTBBox returns a bounding box, not metrics, as some (most?) of the notes above seem to assume. The 8 values it returns specify the 4 corners of this bounding box. So to properly determine the width and height of a string you need to do:



$bbox = ImageFTBBox(...);

$width = abs($bbox[0]) + abs($bbox[2]); // distance from left to right

$height = abs($bbox[1]) + abs($bbox[5]); // distance from top to bottom

sectionthirty1 at yahoo dot com 22-Apr-2004 02:50


Here is a handy example I used to center "dynamic text" onto an image.  



Ex. Say you want to center a clients IP Address onto a picture.  



$ip=$_SERVER['REMOTE_ADDR'];    



$details = imageftbbox($fontsize, 0, $font, $ip, array("linespacing" => 1));



$xcoord = ($imgwidth - $details[4]) / 2;  // this will return the x coordinate centered to your specific image.  Make sure  you set $imgwidth to the width of the image you are using.      



imagettftext($image, $fontsize, 0, $xcoord, $ycoord, $fontcolor, $font, $ip);

ta at NOSPAM dot magicsquare dot info 06-Sep-2002 09:37


i've found a work around for this situation



it seems that height is directly proportional to line spacing so you just have to apply the same factor to image height



for example :



$spacing = 0.7;

$params = array("linespacing" => $spacing);



$box = imageftbbox ($size, 0, $font, $text, $params);

$tw=$box[4]-$box[0]; //image width

$th=($box[1]-$box[5])*$spacing; //image height

phpimageftbbox at juggernaut dot com dot au 14-May-2002 09:56


This function can be used to generate right-aligned text. Just work out how wide the text image is and position it accordingly. Example:



$i_width  = 200;

$i_height = 40;



$string = "Hello World!";

$pointsize = 10;

$fontfile = "/usr/local/lib/ttf/Helve.ttf";



$im = imagecreate($i_width, $i_height);

$black = imagecolorallocate ($im, 0, 0, 0);

$white = imagecolorallocate ($im, 255, 255, 255);



$string_size = ImageFtBbox($pointsize, 0, $fontfile, $string, array("linespacing" => 1));

$s_width  = $string_size[4];

$s_height = $string_size[5];



ImageFtText($im, $pointsize, 0, $i_width - $s_width - 1,  0 - $s_height, $white, $fontfile, $string, array("linespacing" => 1));



Header ("Content-type: image/png");

ImagePNG ($im);

ImageDestroy ($im);