ImagickDraw::setGravity

(PECL imagick 2.0.0)

ImagickDraw::setGravity — Sets the text placement gravity

说明

bool ImagickDraw::setGravity ( int $gravity )

Warning

本函数还未编写文档，仅有参数列表。

Sets the text placement gravity to use when annotating with text.

参数

gravity: GRAVITY_ constant

返回值

没有返回值。

范例

Example #1 ImagickDraw::setGravity()

  <?php
 function  setGravity ( $fillColor ,  $strokeColor ,  $backgroundColor ) {

     $draw  = new \ ImagickDraw ();
     $draw -> setStrokeColor ( $strokeColor );
     $draw -> setFillColor ( $fillColor );
     $draw -> setStrokeWidth ( 1 );
     $draw -> setFontSize ( 24 );

     $gravitySettings  = array(
        \ Imagick :: GRAVITY_NORTHWEST  =>  'NorthWest' ,
        \ Imagick :: GRAVITY_NORTH  =>  'North' ,
        \ Imagick :: GRAVITY_NORTHEAST  =>  'NorthEast' ,
        \ Imagick :: GRAVITY_WEST  =>  'West' ,
        \ Imagick :: GRAVITY_CENTER  =>  'Centre' ,
        \ Imagick :: GRAVITY_SOUTHWEST  =>  'SouthWest' ,
        \ Imagick :: GRAVITY_SOUTH  =>  'South' ,
        \ Imagick :: GRAVITY_SOUTHEAST  =>  'SouthEast' ,
        \ Imagick :: GRAVITY_EAST  =>  'East'
     );

     $draw -> setFont ( "../fonts/Arial.ttf" );

    foreach ( $gravitySettings  as  $type  =>  $description ) {
         $draw -> setGravity ( $type );
         $draw -> annotation ( 50 ,  50 ,  '"'  .  $description  .  '"' );
    }

     $imagick  = new \ Imagick ();
     $imagick -> newImage ( 500 ,  500 ,  $backgroundColor );
     $imagick -> setImageFormat ( "png" );
     $imagick -> drawImage ( $draw );

     header ( "Content-Type: image/png" );
    echo  $imagick -> getImageBlob ();
}

 ?>

用户评论:

[#1] bcre8ve at gmail dot com [2013-09-13 14:15:46]

It appears that the GRAVITY constants have an integer equivalent:
NORTHWEST = 1
NORTH = 2
NORTHEAST = 3
WEST = 4
CENTER = 5
EAST = 6
SOUTHWEST = 7
SOUTH = 8
SOUTHEAST = 9

[#2] alan at ridersite dot org [2007-08-28 07:51:21]

Gravity constants are very useful as they can save having to calculate the placement of variable text strings and font sizes.

For example:
$draw->setGravity (Imagick::GRAVITY_CENTER);
$image->annotateImage($draw, 0, 0, 0, 'The quick brown fox jumps over the lazy dog');

Will horizontally and vertically center the text string.

Note, there are several gravity constants available. See, Constants ?? Imagick class constants