imageantialias

    (PHP 4 >= 4.3.2, PHP 5, PHP 7, PHP 8)

    imageantialias — Should antialias functions be used or not

    Beschreibung

    imageantialias(GdImage$image, bool$enable): bool

    Activate the fast drawing antialiased methods for lines and wired polygons. It does not support alpha components. It works using a direct blend operation. It works only with truecolor images.

    Thickness and styled are not supported.

    Using antialiased primitives with transparent background color can end with some unexpected results. The blend method uses the background color as any other colors. The lack of alpha component support does not allow an alpha based antialiasing method.

    Parameter-Liste

    image

    Ein GdImage-Objekt, das von einer der Funktionen zur Bilderzeugung, z. B. imagecreatetruecolor(), zurückgegeben wurde.

    enable

    Whether to enable antialiasing or not.

    Rückgabewerte

    Gibt bei Erfolg true zurück. Bei einem Fehler wird false zurückgegeben.

    Changelog

    VersionBeschreibung
    8.0.0image erwartet nun eine GdImage-Instanz; vorher wurde eine gültige gd-Ressource erwartet.
    7.2.0imageantialias() is now generally available. Formerly it was only available if PHP was compiled with the bundled version of the GD library.

    Beispiele

    Beispiel #1 A comparison of two lines, one with anti-aliasing switched on

    <?php
    // Setup an anti-aliased image and a normal image
    $aa = imagecreatetruecolor(400, 100);
    $normal = imagecreatetruecolor(200, 100);

    // Switch antialiasing on for one image
    imageantialias($aa, true);

    // Allocate colors
    $red = imagecolorallocate($normal, 255, 0, 0);
    $red_aa = imagecolorallocate($aa, 255, 0, 0);

    // Draw two lines, one with AA enabled
    imageline($normal, 0, 0, 200, 100, $red);
    imageline($aa, 0, 0, 200, 100, $red_aa);

    // Merge the two images side by side for output (AA: left, Normal: Right)
    imagecopymerge($aa, $normal, 200, 0, 0, 0, 200, 100, 100);

    // Output image
    header('Content-type: image/png');

    imagepng($aa);
    imagedestroy($aa);
    imagedestroy($normal);
    ?>

    Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

    Output of example : A comparison of two lines, one with anti-aliasing switched on

    Siehe auch

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