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.)
imageftbbox
(PHP 4 >= 4.0.7, PHP 5)
imageftbbox — freetype2 によるフォントを用いたテキストを囲む箱を取得する
説明
array imageftbbox ( float $size, float $angle, string $font_file, string $text [, array $extrainfo] )警告
この関数は、 現在のところ詳細な情報はありません。引数のリストのみが 記述されています。
パラメータ
- size
- angle
- font_file
- text
- extrainfo
返り値
注意
注意: この関数は、GD 2.0.1 以降を必要とします (2.0.28 以降を推奨します)。
注意: この関数は、PHP が FreeType サポート (--with-freetype-dir=DIR) を有効にしてコンパイルされている場合のみ使用可能です。
変更履歴
| バージョン | 説明 |
|---|---|
| 4.3.5 | extrainfo がオプションになりました。 |
imageftbbox
theo v e -2
29-Dec-2005 12:10
29-Dec-2005 12:10
theo v e
28-Dec-2005 11:20
28-Dec-2005 11:20
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 05:20
15-Jul-2005 05:20
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 04:38
28-May-2004 04:38
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 06:50
22-Apr-2004 06:50
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 12:54
07-Mar-2003 12:54
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 01:37
07-Sep-2002 01:37
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 01:56
15-May-2002 01:56
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);