imagepsbbox()

(PHP 4, PHP 5)

给出一个使用 PostScript Type1 字体的文本方框

说明

imagepsbbox(string $text,resource $font,int $size): arrayimagepsbbox(string $text,resource $font,int $size,int $space,int $tightness,float $angle): array

给出一个使用 PostScript Type1 字体的文本方框。

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。

参数

$text

要写入的文本。

$font_index

imagepsloadfont()所返回的字体资源。

$size

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

$tightness

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

$angle

$angle以角度表示。

返回值

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

范例

imagepsbbox()用法

注释

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

参见

• imagepstext()用 PostScript Type1 字体把文本字符串画在图像上

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  $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;
}

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:

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

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. 

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);

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