imageline

Draw a line

Description

bool imageline ( resource $image , int $x1 , int $y1 , int $x2 , int $y2 , int $color )

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 #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 0.5;
    if (
$x1 == $x2 || $y1 == $y2) {
        return 
imagefilledrectangle($imageround(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 $t sqrt(pow($k2));
    
$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($image$points4$color);
    return 
imagepolygon($image$points4$color);
}

?>

See Also

  • imagecreatetruecolor
  • imagecolorallocate