imagefilltoborder

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

imagefilltoborder — Flood fill to specific color

Descrição

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.

Parâmetros

image: Um objeto GdImage, retornado por uma das funções de criação de imagem, como imagecreatetruecolor().
x: x-coordinate of start.
y: y-coordinate of start.
border_color: The border color. Um identificador de cor criado com imagecolorallocate().
color: The fill color. Um identificador de cor criado com imagecolorallocate().

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Changelog

Versão	Descrição
8.0.0	O parâmetro `image` agora espera uma instância de GdImage; anteriormente, um resource `gd` válido era esperado.

Exemplos

Exemplo #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);
?>

O exemplo acima produzirá algo semelhante a:

Output of example : Filling an ellipse with a color

Notas

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 ¶

20 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

down

admin at worldlanguages dot tk ¶

19 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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