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    ImagickDraw::circle

    (PECL imagick 2, PECL imagick 3)

    ImagickDraw::circle — Draws a circle

    Descrierea

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

    Această funcție nu este documentată în prezent; este disponibilă numai lista sa de argumente.

    Draws a circle on the image.

    Parametri

    ox

    origin x coordinate

    oy

    origin y coordinate

    px

    perimeter x coordinate

    py

    perimeter y coordinate

    Valorile întoarse

    Nu este întoarsă nici o valoare.

    Exemple

    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();
    }

    ?>

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    User Contributed Notes 2 notes

    up
    7
    SkepticaLee
    10 years 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.
    up
    -7
    christian dot reinecke at web dot de
    15 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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