PHP 5.4.36 Released

ImagickDraw::circle

(PECL imagick 2.0.0)

ImagickDraw::circleDraws a circle

Description

bool ImagickDraw::circle ( float $ox , float $oy , float $px , float $py )
Warning

This function is currently not documented; only its argument list is available.

Draws a circle on the image.

Parameters

ox

origin x coordinate

oy

origin y coordinate

px

perimeter x coordinate

py

perimeter y coordinate

Return Values

No value is returned.

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User Contributed Notes 2 notes

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1
SkepticaLee
10 months ago
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.
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0
christian dot reinecke at web dot de
5 years ago
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
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