Should antialias functions be used or not

# imageantialias

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

imageantialias — Should antialias functions be used or not

### Beschreibung

function imageantialias(GdImage `$image`, bool `$enable`): true

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 immer `true` zurück.

### Changelog

Version | Beschreibung
--- | ---
8.0.0 | `image` erwartet nun eine GdImage-Instanz; vorher wurde eine gültige `gd`-Ressource erwartet.
7.2.0 | imageantialias() 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);
    ?>

Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

### Siehe auch

- imagecreatetruecolor() - Create a new true color image

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