imagefilltoborder

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

imagefilltoborder — Flood fill to specific color

Descrizione

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.

Elenco dei parametri

image: Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come 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().

Valori restituiti

Restituisce true in caso di successo, false in caso di fallimento.

Log delle modifiche

Versione	Descrizione
8.0.0	`image` expects a GdImage instance now; previously, a valid `gd` resource was expected.

Esempi

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);
?>

Il precedente esempio visualizzerà qualcosa simile a:

Output of example : Filling an ellipse with a color

Note

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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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

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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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