ImagickDraw::circle

(PECL imagick 2, PECL imagick 3)

ImagickDraw::circle — Draws a circle

说明

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

Warning

本函数还未编写文档，仅有参数列表。

Draws a circle on the image.

参数

ox: origin x coordinate
oy: origin y coordinate
px: perimeter x coordinate
py: perimeter y coordinate

返回值

没有返回值。

范例

Example #1 ImagickDraw::circle() example


<?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();
}

?>

User Contributed Notes

SkepticaLee 27-Jan-2014 09:26


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.

christian dot reinecke at web dot de 23-Jun-2009 06:31


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