PHP: Draw a line

Description

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 #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);

}



?>

imageline

Description

Parameters

Return Values

Examples

See Also