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
int
int
int
int
): bool
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 imagens, 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($im);
?>
O exemplo acima produzirá algo semelhante a:
Notas
The algorithm does not explicitly remember which pixels have already been set, but rather infers that from the color of the pixel, so it cannot distinguish between freshly set pixels and pixels that are already there. That means chosing any fill color that is already used in the image may yield undesired results.
＋add a note
User Contributed Notes 2 notes
edrad at wanadoo dot fr ¶
19 years ago
admin at worldlanguages dot tk ¶
18 years ago
In the example below, for those with newer GD versions, it makes more sense to replace:
imagearc($im, $center, $center, $diametre, $diametre, 0, 360, $el_color);
with:
imageellipse($im, $center, $center, $diametre, $diametre, $el_color);
This is obviously simpler.
