imageline(3) [php man page]

IMAGELINE(3)								 1							      IMAGELINE(3)

imageline - Draw a line

SYNOPSIS

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

DESCRIPTION

	Draws a line between the two given points.

PARAMETERS

	      o $
		image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).

	      o $x1
		- x-coordinate for first point.

	      o $y1
		- y-coordinate for first point.

	      o $x2
		- x-coordinate for second point.

	      o $y2
		- y-coordinate for second point.

	      o $color
		- The line color. A color identifier created with imagecolorallocate(3).

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

       imagecreatetruecolor(3), imagecolorallocate(3).

PHP Documentation Group 													      IMAGELINE(3)