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
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 resource de imagem, retornado por funções de criação de imagens, como 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().
Valor Retornado
Retorna true em caso de sucesso ou false em caso de falha.
Changelog
| Versão | Descrição |
|---|---|
| 8.0.0 |
image expects a GdImage
instance now; previously, a resource was expected.
|
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($im);
?>
O exemplo acima irá imprimir algo similar à:
Notas
The algorithm does not explicitly remember which pixels have already been set, but rather infers that from the color of the pixel, so it cannot distinguish between freshly set pixels and pixels that are already there. That means chosing any fill color that is already used in the image may yield undesired results.
add a note
User Contributed Notes 2 notes
edrad at wanadoo dot fr ¶
20 years ago
admin at worldlanguages dot tk ¶
19 years ago
In the example below, for those with newer GD versions, it makes more sense to replace:
imagearc($im, $center, $center, $diametre, $diametre, 0, 360, $el_color);
with:
imageellipse($im, $center, $center, $diametre, $diametre, $el_color);
This is obviously simpler.
