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Dokumen ini menggunakan Manual laman web PHP Cina Lepaskan
(PECL imagick 2.0.0)
ImagickDraw::circle — Draws a circle
$ox
, float $oy
, float $px
, float $py
)本函数还未编写文档,仅有参数列表。
Draws a circle on the image.
ox
origin x coordinate
oy
origin y coordinate
px
perimeter x coordinate
py
perimeter y coordinate
没有返回值。
Example #1 ImagickDraw::circle()
<?php
function circle ( $strokeColor , $fillColor , $backgroundColor , $originX , $originY , $endX , $endY ) {
//Create a ImagickDraw object to draw into.
$draw = new \ ImagickDraw ();
$strokeColor = new \ ImagickPixel ( $strokeColor );
$fillColor = new \ ImagickPixel ( $fillColor );
$draw -> setStrokeOpacity ( 1 );
$draw -> setStrokeColor ( $strokeColor );
$draw -> setFillColor ( $fillColor );
$draw -> setStrokeWidth ( 2 );
$draw -> setFontSize ( 72 );
$draw -> circle ( $originX , $originY , $endX , $endY );
$imagick = new \ Imagick ();
$imagick -> newImage ( 500 , 500 , $backgroundColor );
$imagick -> setImageFormat ( "png" );
$imagick -> drawImage ( $draw );
header ( "Content-Type: image/png" );
echo $imagick -> getImageBlob ();
}
?>
[#1] SkepticaLee [2014-01-27 21:26:08]
The four values required here are a bit confusing. After all, a circle is defined by three values: the x, y coordinates of the centre, and the radius, r.
The fourth value is redundant, but has to be given, otherwise the function fails. One way of coping with this redundancy is:
<?php
$draw = new ImagickDraw ();
//given that $x and $y are the coordinates of the centre, and $r the radius:
$draw->circle ($x, $y, $x + $r, $y);
?>
There are any number of actions which are synonymous with the last, including:
<?php
$draw->circle ($x, $y, $x, $y + $r);
$draw->circle ($x, $y, $x - $r, $y);
$draw->circle ($x, $y, $x, $y - $r);
// etc, etc.
?>
Hope this helps.
[#2] christian dot reinecke at web dot de [2009-06-23 06:31:47]
This example creates a circle, one part green, one part red using kind of masks for transparency, which you might know from Photoshop. drawImage() is a quick helper for debug output (see code comments) to help you reproduce the process.
<?php
function drawImage(Imagick $im) {
$im->setCompressionQuality(100);
$im->setImageFormat("jpg");
header("Content-Type: image/" . $im->getImageFormat());
echo $im;
exit;
}
// define red/green layer
$layer1 = new Imagick();
$layer1->newImage(100, 100, "none");
$red = new ImagickDraw();
$red->setFillColor("#FF0000");
$red->rectangle(0, 0, 50, 100);
$green = new ImagickDraw();
$green->setFillColor("#00FF00");
$green->rectangle(50, 0, 100, 100);
$layer1->drawImage($red);
$layer1->drawImage($green);
# debug output: two rectangles
# drawImage($layer1);
// define circle mask
$layer2 = new Imagick();
$layer2->newImage(100, 100, "none");
$circle = new ImagickDraw();
$circle->setFillColor("#FFFFFF");
$circle->circle(50, 50, 48, 98);
$layer2->drawImage($circle);
# debug output: the mask
# drawImage($layer2);
// use mask
$layer1->compositeImage($layer2, Imagick::COMPOSITE_DSTIN, 0, 0);
# debug output: the result of our mask usage
# drawImage($layer1);
// define background
$layer3 = new Imagick();
$layer3->newImage(100, 100, "none");
$layer3->compositeImage($layer1, Imagick::COMPOSITE_DEFAULT, 0, 0);
// define ring as background
$layer4 = new Imagick();
$layer4->newImage(100, 100, "white"); // this is our background
$ring1 = new ImagickDraw();
$ring1->setFillColor("black");
$ring1->circle(50, 50, 50, 99);
$layer4->drawImage($ring1);
# debug output: this is a black circle (not our mask, which is similar, but a little bit smaller)
# drawImage($layer4);
// use black circle as background (this creates our circle border)
$layer4->compositeImage($layer3, Imagick::COMPOSITE_DEFAULT, 0, 0);
# debug output: here we go with our circle border
# drawImage($layer4);
// draw separator between red and green rectangle (now semi circles)
$line = new ImagickDraw();
$line->setStrokeWidth(1);
$line->setStrokeColor("black");
$line->line(50, 1, 50, 99);
// add our separator line
$layer4->drawImage($line);
drawImage($layer4);
?>
To understand how the COMPOSITE_* constants effect the image merging process, see here:
http://www.imagemagick.org/Usage/compose/#duff-porter