imagedashedline()

(PHP 4, PHP 5, PHP 7)

画一虚线

说明

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

反对使用本函数。应该用imagesetstyle()和imageline()的组合替代之。

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);
   }
  }
}
?>

The bug reported by 'michi at marel dot at' also exists in PHP version 5.1.1. This functions just works with vertical lines!

It doesn't work for horizontal lines. Use imagesetstyle()

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 :)

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);
}
?>