imagefilltoborder

    (PHP 4, PHP 5, PHP 7, PHP 8)

    imagefilltoborder — Flood fill to specific color

    Description

    imagefilltoborder(
        GdImage $image,
        int $x,
        int $y,
        int $border_color,
        int $color
    ): bool

    imagefilltoborder() performs a flood fill whose border color is defined by border_color. The starting point for the fill is x, y (top left is 0, 0) and the region is filled with color color.

    Parameters

    image

    A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

    x

    x-coordinate of start.

    y

    y-coordinate of start.

    border_color

    The border color. A color identifier created with imagecolorallocate().

    color

    The fill color. A color identifier created with imagecolorallocate().

    Return Values

    Returns true on success or false on failure.

    Changelog

    Version Description
    8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

    Examples

    Example #1 Filling an ellipse with a color

    <?php
    // Create the image handle, set the background to white
    $im = imagecreatetruecolor(100, 100);
    imagefilledrectangle($im, 0, 0, 100, 100, imagecolorallocate($im, 255, 255, 255));

    // Draw an ellipse to fill with a black border
    imageellipse($im, 50, 50, 50, 50, imagecolorallocate($im, 0, 0, 0));

    // Set the border and fill colors
    $border = imagecolorallocate($im, 0, 0, 0);
    $fill = imagecolorallocate($im, 255, 0, 0);

    // Fill the selection
    imagefilltoborder($im, 50, 50, $border, $fill);

    // Output and free memory
    header('Content-type: image/png');
    imagepng($im);
    imagedestroy($im);
    ?>

    The above example will output something similar to:

    Output of example : Filling an ellipse with a color

    Notes

    The algorithm does not explicitly remember which pixels have already been set, but rather infers that from the color of the pixel, so it cannot distinguish between freshly set pixels and pixels that are already there. That means chosing any fill color that is already used in the image may yield undesired results.

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    User Contributed Notes 2 notes

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    1
    edrad at wanadoo dot fr
    21 years ago
    Very useful to build a pseudo-sphere with a color gradient...

    <?php
    $width     = 300;
    $center = $width / 2;
    $colordivs = 255 / $center;
    $im = @imagecreate($width, $width);
    $back_color = imagecolorallocate($im, 20, 30, 40);
    imagefill($im, 0, 0, $back_color);
    for (    $i = 0; $i <= $center; $i++)
    {
    $diametre = $width - 2 * $i;
    $el_color = imagecolorallocate($im, $i * $colordivs, 0, 0);
    imagearc($im, $center, $center, $diametre, $diametre, 0, 360, $el_color);
    imagefilltoborder($im, $center, $center, $el_color, $el_color);
    }
    imagepng($im);
    ?>

    Dark Skull Software
    http://www.darkskull.net
    up
    0
    admin at worldlanguages dot tk
    20 years ago
    In the example below, for those with newer GD versions, it makes more sense to replace:

    imagearc($im, $center, $center, $diametre, $diametre, 0, 360, $el_color);

    with:

    imageellipse($im, $center, $center, $diametre, $diametre, $el_color);

    This is obviously simpler.
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