imagedashedline

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

imagedashedline绘制虚线

说明

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

弃用此函数。使用 imagesetstyle()imageline() 组合替代。

参数

image

由图象创建函数(例如imagecreatetruecolor())返回的 GdImage 对象。

x1

左上 x 坐标。

y1

左上 y 坐标。0,0 为图像的左上角。

x2

右下 x 坐标。

y2

右下 y 坐标。

color

填充颜色。颜色标识符使用 imagecolorallocate() 创建。

返回值

成功时返回 true, 或者在失败时返回 false

更新日志

版本 说明
8.0.0 image 现在需要 GdImage 实例;之前需要有效的 gd resource

示例

示例 #1 imagedashedline() 示例

<?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);
?>

以上示例的输出类似于:

Output of example : imagedashedline()

示例 #2 替代 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);
?>

参见

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User Contributed Notes 5 notes

up
1
tgabor72 at freemail dot hu
13 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
17 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
11 years ago
It doesn't work for horizontal lines. Use imagesetstyle()
up
0
alien-scripts.de
18 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
19 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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