GoLang imageline

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PHP imageline

PHP original manual for imageline [ show | php.net ]

imageline

(PHP 4, PHP 5, PHP 7)

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 = $thick / 2 - 0.5;
    if ($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