ConFoo 2025

imagedashedline

(PHP 4, PHP 5, PHP 7, PHP 8)

imagedashedlineDraw a dashed line

Description

imagedashedline(
    GdImage $image,
    int $x1,
    int $y1,
    int $x2,
    int $y2,
    int $color
): bool

This function is deprecated. Use combination of imagesetstyle() and imageline() instead.

Parameters

image

A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

x1

Upper left x coordinate.

y1

Upper left y coordinate 0, 0 is the top left corner of the image.

x2

Bottom right x coordinate.

y2

Bottom right y coordinate.

color

The fill color. A color identifier created with imagecolorallocate().

Return Values

Returns true on success or false on failure.

Changelog

Version Description
8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

Examples

Example #1 imagedashedline() example

<?php
// Create a 100x100 image
$im = imagecreatetruecolor(100, 100);
$white = imagecolorallocate($im, 0xFF, 0xFF, 0xFF);

// Draw a vertical dashed line
imagedashedline($im, 50, 25, 50, 75, $white);

// Save the image
imagepng($im, './dashedline.png');
imagedestroy($im);
?>

The above example will output something similar to:

Output of example : imagedashedline()

Example #2 Alternative to imagedashedline()

<?php
// Create a 100x100 image
$im = imagecreatetruecolor(100, 100);
$white = imagecolorallocate($im, 0xFF, 0xFF, 0xFF);

// Define our style: First 4 pixels is white and the
// next 4 is transparent. This creates the dashed line effect
$style = Array(
$white,
$white,
$white,
$white,
IMG_COLOR_TRANSPARENT,
IMG_COLOR_TRANSPARENT,
IMG_COLOR_TRANSPARENT,
IMG_COLOR_TRANSPARENT
);

imagesetstyle($im, $style);

// Draw the dashed line
imageline($im, 50, 25, 50, 75, IMG_COLOR_STYLED);

// Save the image
imagepng($im, './imageline.png');
imagedestroy($im);
?>

See Also

add a note

User Contributed Notes 5 notes

up
1
tgabor72 at freemail dot hu
14 years ago
You can use the imagepatternedline() function with extra features instead of imagedashedline() to give a visible dashedlines and other any kind of patterned lines on your images. The routine also manages the thickness of the line. Have fun!

<?php
// imagepatternedline() function
// Routine was developed to draw any kind of straight line with thickness. Routine uses imageline() function to draw line.
// Parameters are (similar to imageline() function):
// $image: (resource) imagefile
// $xstart, $ystart: (int) x,y coordinates for first point
// $xend, $yend: (int) x,y coordinates for last point
// $color: (int) color identifier that created with imagecolorallocate()
// extra parameters:
// $thickness: (int) thickness of line in pixel
// $pattern: (string) pattern of line, which repeats continuously while line is being drawed.
// If there is '1' in the pattern that means the actual dot of line is visible,
// '0' means dot is not visible (space between two line elements).
// All characters regard for one pixel. Default: 1 dot wide dashed line with 4-4 dots and spaces.
// Examples for pattern:
// "1" or "" continuous line
// "10" close dotline
// "10000" dotline
// "111111110000001100000011111111" dotline for design drawing
// "111111111100000011000000110000001111111111" double dotline
// some examples for using imagepatternedline():
// imagepatternedline($image,300,300,442,442,$color,200,""); // a square with 200 length of edge and rotated 45 degrees
// imagepatternedline($image,100,200,289,200,$color,100,
// "11001100000011001111000011001111110000001100001100"
// ."00001111001100111100000011000000110000110011001100"
// ."11000011111100111111000011001111001111000011110000"
// ."1111001111110011000011000000001100110011"); // barcode

function imagepatternedline($image, $xstart, $ystart, $xend, $yend, $color, $thickness=1, $pattern="11000011") {
$pattern=(!strlen($pattern)) ? "1" : $pattern;
$x=$xend-$xstart;
$y=$yend-$ystart;
$length=floor(sqrt(pow(($x),2)+pow(($y),2)));
$fullpattern=$pattern;
while (
strlen($fullpattern)<$length) $fullpattern.=$pattern;
if (!
$length) {
if (
$fullpattern[0]) imagefilledellipse($image, $xstart, $ystart, $thickness, $thickness, $color);
return;
}
$x1=$xstart;
$y1=$ystart;
$x2=$x1;
$y2=$y1;
$mx=$x/$length;
$my=$y/$length;
$line="";
for(
$i=0;$i<$length;$i++){
if (
strlen($line)==0 or $fullpattern[$i]==$line[0]) {
$line.=$fullpattern[$i];
}else{
$x2+=strlen($line)*$mx;
$y2+=strlen($line)*$my;
if (
$line[0]) imageline($image, round($x1), round($y1), round($x2-$mx), round($y2-$my), $color);
$k=1;
for(
$j=0;$j<$thickness-1;$j++) {
$k1=-(($k-0.5)*$my)*(floor($j*0.5)+1)*2;
$k2= (($k-0.5)*$mx)*(floor($j*0.5)+1)*2;
$k=1-$k;
if (
$line[0]) {
imageline($image, round($x1)+$k1, round($y1)+$k2, round($x2-$mx)+$k1, round($y2-$my)+$k2, $color);
if (
$y) imageline($image, round($x1)+$k1+1, round($y1)+$k2, round($x2-$mx)+$k1+1, round($y2-$my)+$k2, $color);
if (
$x) imageline($image, round($x1)+$k1, round($y1)+$k2+1, round($x2-$mx)+$k1, round($y2-$my)+$k2+1, $color);
}
}
$x1=$x2;
$y1=$y2;
$line=$fullpattern[$i];
}
}
$x2+=strlen($line)*$mx;
$y2+=strlen($line)*$my;
if (
$line[0]) imageline($image, round($x1), round($y1), round($xend), round($yend), $color);
$k=1;
for(
$j=0;$j<$thickness-1;$j++) {
$k1=-(($k-0.5)*$my)*(floor($j*0.5)+1)*2;
$k2= (($k-0.5)*$mx)*(floor($j*0.5)+1)*2;
$k=1-$k;
if (
$line[0]) {
imageline($image, round($x1)+$k1, round($y1)+$k2, round($xend)+$k1, round($yend)+$k2, $color);
if (
$y) imageline($image, round($x1)+$k1+1, round($y1)+$k2, round($xend)+$k1+1, round($yend)+$k2, $color);
if (
$x) imageline($image, round($x1)+$k1, round($y1)+$k2+1, round($xend)+$k1, round($yend)+$k2+1, $color);
}
}
}
?>
up
1
ProfessorNeo at gmx dot de
18 years ago
The bug reported by 'michi at marel dot at' also exists in PHP version 5.1.1. This functions just works with vertical lines!
up
0
ihsanduvac at gmail dot com
12 years ago
It doesn't work for horizontal lines. Use imagesetstyle()
up
0
alien-scripts.de
19 years ago
I make my own dashedline:

<?
for($l=50;$l<=550;$l+=5)
{
if($da == 0) { $da = 1; }
elseif($da == 1){
imageline($bild,$l,50,$l+5,50,$green);
$da = 0; }
}
?>

$l is the x-value
and we have a dashed line :)
up
-1
michi at marel dot at
21 years ago
There's a bug till PHP 4.0.4 in this function. You can only draw vertical dashed lines. To draw other dashed lines you can set <ImageSetStyle> to a special dashed line and draw it by <ImageLine>.

Sample code:
<?php
function MDashedLine($image, $x0, $y0, $x1, $y1, $fg, $bg)
{
$st = array($fg, $fg, $fg, $fg, $bg, $bg, $bg, $bg);
ImageSetStyle($image, $st);
ImageLine($image, $x0, $y0, $x1, $y1, IMG_COLOR_STYLED);
}
?>
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