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imageline

Draw a line (PHP 4, PHP 5)
bool imageline ( resource image, int x1, int y1, int x2, int y2, int color )

imageline() draws a line between the two given points.

Parameters

image

An image resource, 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.

Examples

Example 1016. 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);
}

?>