Note that a color allocated with imagecolorexactalpha won't show alpha (it will be opaque) when used with imageline(). Use imagerectangle() set to your normal start and end points instead.
Ensure that the image is created via imagecreatetruecolor() as well!
imagecolorexactalpha
(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorexactalpha — Get the index of the specified color + alpha
Descrierea
imagecolorexactalpha
( resource
$image
, int $red
, int $green
, int $blue
, int $alpha
) : intReturns the index of the specified color+alpha in the palette of the image.
Parametri
-
image -
O resursă - imagine, întoarsă de una din funcțiile de creare a imaginilor, cum ar fi imagecreatetruecolor().
-
red -
Valoarea componentei roșii.
-
green -
Valoarea componentei verzi.
-
blue -
Valoarea componentei albastre.
-
alpha -
A value between
0and127.0indicates completely opaque while127indicates completely transparent.
Valorile întoarse
Returns the index of the specified color+alpha in the palette of the image, or -1 if the color does not exist in the image's palette.
Exemple
Example #1 Get colors from the GD logo
<?php
// Setup an image
$im = imagecreatefrompng('./gdlogo.png');
$colors = Array();
$colors[] = imagecolorexactalpha($im, 255, 0, 0, 0);
$colors[] = imagecolorexactalpha($im, 0, 0, 0, 127);
$colors[] = imagecolorexactalpha($im, 255, 255, 255, 55);
$colors[] = imagecolorexactalpha($im, 100, 255, 52, 20);
print_r($colors);
// Free from memory
imagedestroy($im);
?>
Exemplul de mai sus va afișa ceva similar cu:
Array
(
[0] => 16711680
[1] => 2130706432
[2] => 939524095
[3] => 342163252
)
A se vedea și
- imagecolorclosestalpha() - Get the index of the closest color to the specified color + alpha
add a note
User Contributed Notes 2 notes
matt at matt-darby dot com ¶
19 years ago
phpdoc-comment at aditus dot nu ¶
22 years ago
What might be misleading in the docs is that if the specified color + alpha channel does not exist it will be created. So if you like to use an alpha channel in your image enable alpha blending and then create you color using this method.
