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

2018-04-18 20:52:51
linefo
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最后编辑:linefo 于 2018-04-18 21:00:32

imageftbbox

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

imageftbbox给出一个使用 FreeType 2 字体的文本框

说明

array imageftbbox ( float $size , float $angle , string $fontfile , string $text [, array $extrainfo ] )

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

参数

size

字体的尺寸。根据 GD 的版本,为像素尺寸(GD1)或点(磅)尺寸(GD2)。

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(300150);
$black imagecolorallocate($im000);
$white imagecolorallocate($im255255255);

// Set the background to be white
imagefilledrectangle($im00299299$white);

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

// First we create our bounding box
$bbox imageftbbox(100$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($im100$x$y$black$font'The PHP Documentation Group');

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

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

注释

Note: 此函数需要 GD 2.0.1 或更高版本(推荐 2.0.28 及更高版本)。

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.