imageftbbox

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theo v e -2
28-Dec-2005 11:10


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.)

theo v e
28-Dec-2005 10:20


IF we accept the idea that a bouding box is returned then:

    $bbox= imageftbbox ( $size, $angle, $font, $txt);

    $width = abs($bbox[4] - $bbox[0]);

    $height = abs($bbox[1] - $bbox[5]);

may be a better kind of math. But it depends... You may want to subtract yet another '1' from both the width and the height.

But try drawing a "p" and next try a "d". Their bounding boxes differ 1 px in height. Of course the respective boxes, by  imagefttext(), are placed at a different y coordinate. I noticed that if a "p" or a "b" is drawn at (0, 30) the first character of the string actually starts on, fills, the third horizontal pixel. Also: if your image is only 30 pixels in heigth, drawing text at (0, 30) means that the bottoms parts of "p", "q", "y" and alike are somewhere else...

fernando
15-Jul-2005 04:20


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
28-May-2004 03:38


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 05:50


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);

Brian at PrintsMadeEasy dot com
07-Mar-2003 11:54


I noticed that PHP's True Type functions do not allow you to create text blocks with multiple lines that automatically adjust for alignment.  I wrote a function that will allow you to generate images with multiple lines, control the alignment, and handle rotation.  I hope it helps someone.



There was too much code to paste on this message post so you can grab it off of my webserver.  I also created an example page so that you can see the code in action.



Example Page:

http://www.PrintsMadeEasy.com/code_samples/php/text_generation.php



Download the Text file:

http://www.PrintsMadeEasy.com /code_samples/php/text_generation.txt

ta at NOSPAM dot magicsquare dot info
07-Sep-2002 12:37


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
15-May-2002 12:56


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);

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