imageline
(PHP 4, PHP 5, PHP 7, PHP 8)
imageline — Draw a line
Description
Draws a line between the two given points.
Parameters
-
image -
A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
-
x1 -
x-coordinate for first point.
-
y1 -
y-coordinate for first point.
-
x2 -
x-coordinate for second point.
-
y2 -
y-coordinate for second point.
-
color -
The line color. A color identifier created with imagecolorallocate().
Return Values
Returns true on success or false on failure.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
image expects a GdImage
instance now; previously, a resource was expected.
|
Examples
Example #1 Drawing a thick line
<?php
function imagelinethick($image, $x1, $y1, $x2, $y2, $color, $thick = 1)
{
/* this way it works well only for orthogonal lines
imagesetthickness($image, $thick);
return imageline($image, $x1, $y1, $x2, $y2, $color);
*/
if ($thick == 1) {
return imageline($image, $x1, $y1, $x2, $y2, $color);
}
$t = $thick / 2 - 0.5;
if ($x1 == $x2 || $y1 == $y2) {
return imagefilledrectangle($image, round(min($x1, $x2) - $t), round(min($y1, $y2) - $t), round(max($x1, $x2) + $t), round(max($y1, $y2) + $t), $color);
}
$k = ($y2 - $y1) / ($x2 - $x1); //y = kx + q
$a = $t / sqrt(1 + pow($k, 2));
$points = array(
round($x1 - (1+$k)*$a), round($y1 + (1-$k)*$a),
round($x1 - (1-$k)*$a), round($y1 - (1+$k)*$a),
round($x2 + (1+$k)*$a), round($y2 - (1-$k)*$a),
round($x2 + (1-$k)*$a), round($y2 + (1+$k)*$a),
);
imagefilledpolygon($image, $points, 4, $color);
return imagepolygon($image, $points, 4, $color);
}
?>
See Also
- imagecreatetruecolor() - Create a new true color image
- imagecolorallocate() - Allocate a color for an image
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