GD and Image 函数
在线手册：中文 英文
PHP手册

imagepsbbox

(PHP 4, PHP 5)

imagepsbbox — 给出一个使用 PostScript Type1 字体的文本方框

说明

array imagepsbbox ( string $text , int $font , int $size [, int $space ], int $tightness , float $angle )

size 以像素表示。

space 可以用来改变字体中默认间距的值。此值将被加到通常的值上，可以为负值。

tightness 可以控制字符之间的间距。此值将被加到通常字符宽度上，可以为负值。

angle 以角度表示。

space 和 tightness 以字符间距单元表示，1 个单元为 1 em-square 的一千分之一。

space，tightness 和 angle 参数为可选项。

围绕文本范围的虚拟方框是用从字符度量学中的可用信息来计算的，不幸的是往往和实际上光栅生成的文本的结果有少许不同。如果角度为 0 度，（根据经验）文本在每个方向上都需要多 1 个像素。

Note: 此函数仅在 PHP 编译时指定了 --with-t1lib[=DIR] 时可用。

本函数返回包含有下列单元的数组：

0 左下角的 X 坐标
1 左下角的 Y 坐标
2 右上角的 X 坐标
3 右上角的 Y 坐标

参见 imagepstext()。

参数

text

The text to be written.

font_index

A font resource, returned by imagepsloadfont().

size

size is expressed in pixels.

space

Allows you to change the default value of a space in a font. This amount is added to the normal value and can also be negative. Expressed in character space units, where 1 unit is 1/1000th of an em-square.

tightness

tightness allows you to control the amount of white space between characters. This amount is added to the normal character width and can also be negative. Expressed in character space units, where 1 unit is 1/1000th of an em-square.

angle

angle is in degrees.

返回值

Returns an array containing the following elements:

0 left x-coordinate
1 upper y-coordinate
2 right x-coordinate
3 lower y-coordinate

范例

Example #1 imagepsbbox() usage

<?php
// Create image handle
$im = imagecreatetruecolor(200, 200);

// Allocate colors
$black = imagecolorallocate($im, 0, 0, 0);
$white = imagecolorallocate($im, 255, 255, 255);

// Load the PostScript Font
$font = imagepsloadfont('font.pfm');

// Make a bounding box for the font
$bbox = imagepsbbox('Sample text is simple', $font, 12);

// Define our X and Y cordinates
$x = ($bbox[2] / 2) - 10;
$y = ($bbox[3] / 2) - 10;

// Write the font to the image
imagepstext($im, 'Sample text is simple', $font, 12, $black, $white, $x, $y);

// Output and free memory
header('Content-type: image/png');

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

注释

Note: 此函数仅在 PHP 编译时指定了 --with-t1lib[=DIR] 时可用。

参见

GD and Image 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 给出一个使用 PostScript Type1 字体的文本方框

用户评论:

eikie (05-May-2008 05:32)

in my code below, there is an error!

replace
$w += abs($bb[3])-abs($bb[1]); // accumulate width

with
$w += abs($bb[2])-abs($bb[0]); // accumulate width

also after
$bb = imagepsbbox($c, $font, $size); // calculate width

you can add this line because spaces make odd values...
if ($c == ' ' ) $bb = imagepsbbox('i', $font, $size);

eikie (05-May-2008 04:34)

I have a given image width and need to render a long string on that image. By using the following function I'm, able to get an array of strings which each will fit into the images width. It might need a lot of CPU time, but it's cool:

// Function to return an Array of Strings
// Arguments: String to be wrapped, maximum width in pixels of each line, font and fontsize
function imgwordwrap($s, $maxWidth, $font, $size) {
  // Make an empty ArrayList
  $a = array();
  $w = 0;    // Accumulate width of chars
  $i = 0;      // Count through chars
  $rememberSpace = 0; // Remember where the last space was
  // As long as we are not at the end of the String
  while ($i < strlen($s)) {
    // Current char
    $c = substr($s, $i, 1);
    $bb = imagepsbbox($c, $font, $size); // calculate width
    $w += abs($bb[3])-abs($bb[1]); // accumulate width
    if ($c == ' ') $rememberSpace = $i; // Are we a blank space?
    if ($w > $maxWidth) {  // Have we reached the end of a line?
      $sub = substr($s,0,$rememberSpace); // Make a substring
            // Chop off space at beginning
            if (substr($sub,0,1)==' ') $sub = substr($sub,1);
      // Add substring to the array
      $a[] = $sub;
      // Reset everything
      $s = substr($s,$rememberSpace);
      $i = 0;
      $w = 0;
    }
    else {
      $i++;  // Keep going!
    }
  }
 
  // Take care of the last remaining line
  trim($s);
  if (substr($s,0,1)==' ') $s = substr($s,1);
  $a[] = $s;
 
  return $a;
}

honza dot bartos at gmail dot com (23-Oct-2006 10:25)

When using imagepsbbox, keep in mind, that meaning of y-coordinates is slightly different here. Y-coordinates returned by this function are related to the baseline of the text starting at point [0,0]. Positive values represent points ABOVE the baseline, negative values represent points BELOW the baseline. That is why the lower left y-coordinate is always smaller here than the upper right y-coordinate (these two coordinates are actualy values of metrics.descent and metrics.ascent - see T1Lib docs).

So when you want to place some text using coordinates of the top left corner (for example [100,100]), use this:

<?php

$x = 100;
$y = 100;
$text = "Dodge this";
$fontsize=18;
$font=imagepsloadfont("somefont.pfb");
list($lx,$ly,$rx,$ry) = imagepsbbox($text,$font,$fontsize);
imagepstext ($someimage, $text, $font, $fontsize, $somecolor, $somecolor, $x, $y + $ry);

?>

Hope it helps someone, I got stuck with this for a while.

daniel at dantec dot NO_SPAM dot nl (18-Apr-2002 05:23)

When using imagepsbbox, you are probably trying to do something like creating a button with text, so that the button is large enough for the text...
Below is a very simple example of making a black button just big enough to display white text on it.

<?php

//if text is no variable set sample text
if (!$text)
    $text = "This is a sample text";
   
// set the font size
$fontsize=14;

// load the font to use
$font=ImagePsLoadFont("/fonts/ariam___.pfb");

//get the left lower corner and the right upper
list($lx,$ly,$rx,$ry) = imagepsbbox($text,$font,$fontsize,0,0,0);

// calculate the size of the text
$textwidth = $rx - $lx;
$textheight = $ry - $ly;

// make an image 40 pixels wider and 20 pixels higher than the text
$imh = $textheight + 20;
$imw = $textwidth + 40;
$im = imageCreate( $imw, $imh );

//define colors, first color is used as background color!
$black  = ImageColorAllocate ($im, 0, 0, 0);
$white = ImageColorAllocate ($im, 255, 255, 255);

//create the text (with the same parameters as imagepsbbox!)
ImagePSText ($im, "$text", $font, $fontsize, $white, $white, 20, 20,'','','',4);

//send the header
header("Content-type: image/jpeg");

// create the image
ImageJPEG ($im,"",100);

//destroy the image & font to free memory
Imagepsfreefont ( $font );
ImageDestroy ( $im );

?>