PHP TOP

imageline

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

imageline — 直線を描画する

説明

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

指定したふたつの点を結ぶ直線を描画します。

パラメータ

image: imagecreatetruecolor()のような画像作成関数が返す GdImage オブジェクト。
x1: 最初の点の x 座標。
y1: 最初の点の y 座標。
x2: 二番目の点の x 座標。
y2: 二番目の点の y 座標。
color: 直線の色。imagecolorallocate() で作成された色識別子。

戻り値

成功した場合に true を、失敗した場合に false を返します。

変更履歴

バージョン	説明
8.0.0	`image` は、 GdImage クラスのインスタンスを期待するようになりました。これより前のバージョンでは、有効な `gd` resource が期待されていました。

例

例1 太い線を描画する

<?php

function imagelinethick($image, $x1, $y1, $x2, $y2, $color, $thick = 1)
{
    /* この方法は直行する線の場合のみうまく動作します
    imagesetthickness($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);
}

?>

参考

imagecreatetruecolor() - TrueColor イメージを新規に作成する
imagecolorallocate() - 画像で使用する色を作成する

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User Contributed Notes 28 notes

down

Jonathan W. ¶

17 years ago

I've modified the previous entry for drawing on a polar coordinate system to better represent angles based on a 360º whole circle bearing.

<?php

function imagepolarline($image,$x1,$y1,$length,$angle,$color)
{
    $x2 = $x1 + sin( deg2rad($angle) ) * $length;
    $y2 = $y1 + cos( deg2rad($angle+180) ) * $length;

    imageline($image,$x1,$y1,$x2,$y2,$color);
}

?>

down

pb_2001 at haefft dot de ¶

18 years ago

This is a function to make a dotted line. It accepts (it actually requires) 7 parameters and returns 1 if everything went OK and 0 if there was a problem.

int imagelinedotted ( resource im, int x1, int y1, int x2, int y2, int dist, int col )

imagelinedotted() draws a line from x1, y1 to x2, y2 (top left is 0, 0) in image im of colour col where dist defines the distance (measured in pixels) between one dot and another.

<?php
function imagelinedotted ($im, $x1, $y1, $x2, $y2, $dist, $col) {
    $transp = imagecolortransparent ($im);
    
    $style = array ($col);
    
    for ($i=0; $i<$dist; $i++) {
        array_push($style, $transp);        // Generate style array - loop needed for customisable distance between the dots
    }
    
    imagesetstyle ($im, $style);
    return (integer) imageline ($im, $x1, $y1, $x2, $y2, IMG_COLOR_STYLED);
    imagesetstyle ($im, array($col));        // Reset style - just in case...
}
?>

down

sbm007 at gmail dot com ¶

15 years ago

Here is a analog clock representation of the system time along with digits for hours and little dots for minutes/seconds:

<?php
$img = imagecreatetruecolor(450, 450);

$white = imagecolorallocate($img, 255, 255, 255);
$red = imagecolorallocate($img, 255, 0, 0);
$black = imagecolorallocate($img, 0, 0, 0);
$grey = imagecolorallocate($img, 211, 211, 211);

imagefill($img, 0, 0, $white);
imagearc($img, 224, 224, 400, 400, 0, 0, $black);
imagefilledarc($img, 224, 224, 15, 15, 0, 0, $black, IMG_ARC_PIE);

for ($zz = 0; $zz < 60; $zz++) {
    $digitCoords['x'][] = 175 * cos(deg2rad(($zz-10) * (360/60))) + 224;
    $digitCoords['y'][] = 175 * sin(deg2rad(($zz-10) * (360/60))) + 224;
}

for ($zz = 0; $zz < 60; $zz++) {
    if ($zz % 5 == 0)
        imagestring($img, 5, $digitCoords['x'][$zz] - 4, $digitCoords['y'][$zz] - 6, ($zz/5) + 1, $black);
    else
        imagefilledarc($img, $digitCoords['x'][$zz], $digitCoords['y'][$zz], 3, 3, 0, 0, $grey, IMG_ARC_PIE);
}

$seconds = date('s');
$minutes = date('i') + ($seconds/60);
$hours = date('h') + ($minutes/60);

$r_sec = 175;
$r_min = 175;
$r_hr = 125;

$x_sec = $r_sec * cos(deg2rad(($seconds-15) * (360/60))) + 224;
$y_sec = $r_sec * sin(deg2rad(($seconds-15) * (360/60))) + 224;

$x_min = $r_min * cos(deg2rad(($minutes-15) * (360/60))) + 224;
$y_min = $r_min * sin(deg2rad(($minutes-15) * (360/60))) + 224;

$x_hr = $r_hr * cos(deg2rad(($hours-3) * (360/12))) + 224;
$y_hr = $r_hr * sin(deg2rad(($hours-3) * (360/12))) + 224;

imageline($img, 224, 224, $x_sec, $y_sec, $red);
imagesetthickness($img, 3);
imageline($img, 224, 224, $x_min, $y_min, $black);
imagesetthickness($img, 5);
imageline($img, 224, 224, $x_hr, $y_hr, $black);

header("Content-type: image/png");
imagepng($img);

imagedestroy($img);
?>

down

d [AT] sprid [DOT] de ¶

19 years ago

Here my function do clear all problems. With this, you can draw firstly smooth lines (basic code adapted from code_couturier at graffiti dot net, with some performance changes). The special is, you can define the alpha-value of the line (0 = normal smooth line, 127 = fully transparent). Change whatever you want to make it better, but post your results ;) 

<?php
/**
 * function imageSmoothAlphaLine() - version 1.0
 * Draws a smooth line with alpha-functionality
 *
 * @param   ident    the image to draw on
 * @param   integer  x1
 * @param   integer  y1
 * @param   integer  x2
 * @param   integer  y2
 * @param   integer  red (0 to 255)
 * @param   integer  green (0 to 255)
 * @param   integer  blue (0 to 255)
 * @param   integer  alpha (0 to 127)
 *
 * @access  public
 *
 * @author  DASPRiD <d@sprid.de>
 */
function imageSmoothAlphaLine ($image, $x1, $y1, $x2, $y2, $r, $g, $b, $alpha=0) {
  $icr = $r;
  $icg = $g;
  $icb = $b;
  $dcol = imagecolorallocatealpha($image, $icr, $icg, $icb, $alpha);
  
  if ($y1 == $y2 || $x1 == $x2) 
    imageline($image, $x1, $y2, $x1, $y2, $dcol);
  else {
    $m = ($y2 - $y1) / ($x2 - $x1);
    $b = $y1 - $m * $x1;

    if (abs ($m) <2) {
      $x = min($x1, $x2);
      $endx = max($x1, $x2) + 1;

      while ($x < $endx) {
        $y = $m * $x + $b;
        $ya = ($y == floor($y) ? 1: $y - floor($y));
        $yb = ceil($y) - $y;
   
        $trgb = ImageColorAt($image, $x, floor($y));
        $tcr = ($trgb >> 16) & 0xFF;
        $tcg = ($trgb >> 8) & 0xFF;
        $tcb = $trgb & 0xFF;
        imagesetpixel($image, $x, floor($y), imagecolorallocatealpha($image, ($tcr * $ya + $icr * $yb), ($tcg * $ya + $icg * $yb), ($tcb * $ya + $icb * $yb), $alpha));
  
        $trgb = ImageColorAt($image, $x, ceil($y));
        $tcr = ($trgb >> 16) & 0xFF;
        $tcg = ($trgb >> 8) & 0xFF;
        $tcb = $trgb & 0xFF;
        imagesetpixel($image, $x, ceil($y), imagecolorallocatealpha($image, ($tcr * $yb + $icr * $ya), ($tcg * $yb + $icg * $ya), ($tcb * $yb + $icb * $ya), $alpha));
  
        $x++;
      }
    } else {
      $y = min($y1, $y2);
      $endy = max($y1, $y2) + 1;

      while ($y < $endy) {
        $x = ($y - $b) / $m;
        $xa = ($x == floor($x) ? 1: $x - floor($x));
        $xb = ceil($x) - $x;
  
        $trgb = ImageColorAt($image, floor($x), $y);
        $tcr = ($trgb >> 16) & 0xFF;
        $tcg = ($trgb >> 8) & 0xFF;
        $tcb = $trgb & 0xFF;
        imagesetpixel($image, floor($x), $y, imagecolorallocatealpha($image, ($tcr * $xa + $icr * $xb), ($tcg * $xa + $icg * $xb), ($tcb * $xa + $icb * $xb), $alpha));
  
        $trgb = ImageColorAt($image, ceil($x), $y);
        $tcr = ($trgb >> 16) & 0xFF;
        $tcg = ($trgb >> 8) & 0xFF;
        $tcb = $trgb & 0xFF;
        imagesetpixel ($image, ceil($x), $y, imagecolorallocatealpha($image, ($tcr * $xb + $icr * $xa), ($tcg * $xb + $icg * $xa), ($tcb * $xb + $icb * $xa), $alpha));
  
        $y ++;
      }
    }
  }
} // end of 'imageSmoothAlphaLine()' function
?>

down

kramesch_NOSPAM_ at _nospam_idsolutions dot at ¶

22 years ago

Here is a simple code to draw a line with an arbitrary stroke. The parameter aStroke is treated as a cyclic boolean array where true equals "set a point"
e.g. $aDotStroke = array(true,false);

function ImageStrokeLine($im,$x1,$y1,$x2,$y2,$farbe, $aStroke)
  {
    $deltax = abs($x2 - $x1);        
    $deltay = abs($y2 - $y1);        
    $x = $x1;                       
    $y = $y1;                       
    
    if ($x2 >= $x1)                 
    {
      $xinc1 = 1;
      $xinc2 = 1;
    }
    else                          
    {
      $xinc1 = -1;
      $xinc2 = -1;
    }
    
    if ($y2 >= $y1)                 
    {
      $yinc1 = 1;
      $yinc2 = 1;
    }
    else                          
    {
      $yinc1 = -1;
      $yinc2 = -1;
    }
    
    if ($deltax >= $deltay)  
    {
      $xinc1 = 0;                 
      $yinc2 = 0;                 
      $den = $deltax;
      $num = $deltax / 2;
      $numadd = $deltay;
      $numpixels = $deltax; 
    }
    else                          
    {
      $xinc2 = 0;             
      $yinc1 = 0;             
      $den = $deltay;
      $num = $deltay / 2;
      $numadd = $deltax;
      $numpixels = $deltay; 
    }
    
    for ($curpixel = 0; $curpixel <= $numpixels; $curpixel++)
    {
      if ($iStrokeCount >= count($aStroke))
      {
        $iStrokeCount = 0;
      }
  
      if ($aStroke[$iStrokeCount++]) 
      {
        ImageSetPixel($im,$x, $y,$farbe);            
      }            
      $num += $numadd;            
      if ($num >= $den)             
      {
        $num -= $den;               
        $x += $xinc1;               
        $y += $yinc1;               
      }
      $x += $xinc2;                 
      $y += $yinc2;                 
    }
  }

down

Nils ¶

12 years ago

A quick function using imageline that I wrote so i could specify a starting point, angle and length of vector.

Thought other people might find this useful.

<?php
$size = 600;
$img = imagecreatetruecolor($size, $size);

$white = imagecolorallocate($img, 255, 255, 255);
$black = imagecolorallocate($img, 0, 0, 0);

imagefilledrectangle($img,0,0,$size,$size,$white);

function Vector($palette,$startx,$starty,$angle,$length,$colour){
    $angle = deg2rad($angle);
    $endx = $startx+cos($angle)*$length;
    $endy = $starty-sin($angle)*$length;
    return(imageline($palette,$startx,$starty,$endx,$endy,$colour));
}

Vector($img,$size/2,$size/2,30,200,$black);

header("Content-type: image/png");
imagepng($img);

?>

For this script angles work in a anti-clockwise direction (modify + and - in function to change start of 0 degrees and also direction of angle calculated)

down

nanobot at chipx86 dot com ¶

21 years ago

Here is a function for making antialiased lines:

 function imagesmoothline ( $image , $x1 , $y1 , $x2 , $y2 , $color )
 {
  $colors = imagecolorsforindex ( $image , $color );
  if ( $x1 == $x2 )
  {
   imageline ( $image , $x1 , $y1 , $x2 , $y2 , $color ); // Vertical line
  }
  else
  {
   $m = ( $y2 - $y1 ) / ( $x2 - $x1 );
   $b = $y1 - $m * $x1;
   if ( abs ( $m ) <= 1 )
   {
    $x = min ( $x1 , $x2 );
    $endx = max ( $x1 , $x2 );
    while ( $x <= $endx )
    {
     $y = $m * $x + $b;
     $y == floor ( $y ) ? $ya = 1 : $ya = $y - floor ( $y );
     $yb = ceil ( $y ) - $y;
     $tempcolors = imagecolorsforindex ( $image , imagecolorat ( $image , $x , floor ( $y ) ) );
     $tempcolors['red'] = $tempcolors['red'] * $ya + $colors['red'] * $yb;
     $tempcolors['green'] = $tempcolors['green'] * $ya + $colors['green'] * $yb;
     $tempcolors['blue'] = $tempcolors['blue'] * $ya + $colors['blue'] * $yb;
     if ( imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) == -1 ) imagecolorallocate ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] );
     imagesetpixel ( $image , $x , floor ( $y ) , imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) );
     $tempcolors = imagecolorsforindex ( $image , imagecolorat ( $image , $x , ceil ( $y ) ) );
     $tempcolors['red'] = $tempcolors['red'] * $yb + $colors['red'] * $ya;
      $tempcolors['green'] = $tempcolors['green'] * $yb + $colors['green'] * $ya;
     $tempcolors['blue'] = $tempcolors['blue'] * $yb + $colors['blue'] * $ya;
     if ( imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) == -1 ) imagecolorallocate ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] );
     imagesetpixel ( $image , $x , ceil ( $y ) , imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) );
     $x ++;
    }
   }
   else
   {
    $y = min ( $y1 , $y2 );
    $endy = max ( $y1 , $y2 );
    while ( $y <= $endy )
    {
     $x = ( $y - $b ) / $m;
     $x == floor ( $x ) ? $xa = 1 : $xa = $x - floor ( $x );
     $xb = ceil ( $x ) - $x;
     $tempcolors = imagecolorsforindex ( $image , imagecolorat ( $image , floor ( $x ) , $y ) );
     $tempcolors['red'] = $tempcolors['red'] * $xa + $colors['red'] * $xb;
     $tempcolors['green'] = $tempcolors['green'] * $xa + $colors['green'] * $xb;
     $tempcolors['blue'] = $tempcolors['blue'] * $xa + $colors['blue'] * $xb;
     if ( imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) == -1 ) imagecolorallocate ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] );
     imagesetpixel ( $image , floor ( $x ) , $y , imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) );
     $tempcolors = imagecolorsforindex ( $image , imagecolorat ( $image , ceil ( $x ) , $y ) );
     $tempcolors['red'] = $tempcolors['red'] * $xb + $colors['red'] * $xa;
     $tempcolors['green'] = $tempcolors['green'] * $xb + $colors['green'] * $xa;
     $tempcolors['blue'] = $tempcolors['blue'] * $xb + $colors['blue'] * $xa;
     if ( imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) == -1 ) imagecolorallocate ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] );
     imagesetpixel ( $image , ceil ( $x ) , $y , imagecolorexact ( $image , $tempcolors['red'] , $tempcolors['green'] , $tempcolors['blue'] ) );
     $y ++;
    }
   }
  }
 }

EDITOR: My previous code contained bugs. Please use this one instead.

down

ruturaj_v at yahoo dot com ¶

20 years ago

here is a function that helps you create arrows...

<?php
function get_arrowheads ($x1, $y1, $x2, $y2, $arrhead, $arrang) {
    $debug = false;
    
    define("INFINITE", 'INFINITE');
    if (($x2-$x1)==0) {
        if ($y1 == 0) {
            $slope = 0;
        } else {
            $slope = INFINITE;
        }
    } else {
        $slope = -($y2-$y1)/($x2-$x1);
    }

    //$slope = number_format($slope, 2, '.','');
    if ($slope == 'INFINITE') {
        $ang = 90;
    } else {
        $ang = atan ($slope);
        $ang = ($ang * 180)/pi();
    }
    //$ang = number_format($ang, 2, '.', '');
    //echo ($ang);
    //exit;

    //convert the angle
    $arrang1 = ($ang - $arrang);
    $arrangdeg1 = ($ang - $arrang);
    //echo ($arrang1);exit;
    $arrang1 = ($arrang1*pi())/180;

    $arrang2 = ($ang + $arrang);
    $arrangdeg2 = ($ang + $arrang);
    $arrang2 = ($arrang2*pi())/180;
    //echo ($arrang1);

    $arx1 = (floor(cos($arrang1)*$arrhead));
    $ary1 = (floor(sin($arrang1)*$arrhead));
    $arx2 = (floor(cos($arrang2)*$arrhead));
    $ary2 = (floor(sin($arrang2)*$arrhead));
    if ($debug) {
        echo ("Values of arx1.. before add/sub</br>");
        echo ("$arx1,$ary1&nbsp;&nbsp;&nbsp;$arx2,$ary2</br>");
    }
    if ($ang==0) {
        if ($x2 > $x1) {
            $arx1 = $x2 - $arx1;    $ary1 = $y2 - $ary1;
            $arx2 = $x2 - $arx2;    $ary2 = $y2 - $ary2;
        } elseif ($x2 < $x1) {
            $arx1 = $x2 + $arx1;    $ary1 = $y2 - $ary1;
            $arx2 = $x2 + $arx2;    $ary2 = $y2 - $ary2;
        }
    }
    if ($ang > 0 && $ang < 90) {
        if (($x2 > $x1) && ($y2 < $y1)) {
            $arx1 = $x2 - $arx1;    $ary1 = $y2 + $ary1;
            $arx2 = $x2 - $arx2;    $ary2 = $y2 + $ary2;
        } elseif (($x2 < $x1) && ($y2 > $y1)) {
            $arx1 = $x2 + $arx1;    $ary1 = $y2 - $ary1;
            $arx2 = $x2 + $arx2;    $ary2 = $y2 - $ary2;
        }
    }
    if ($ang==90) {
        if (($y2 > $y1)) {
            $arx1 = $x2 - $arx1;    $ary1 = $y2 - $ary1;
            $arx2 = $x2 - $arx2;    $ary2 = $y2 - $ary2;
        } elseif (($y2 < $y1)) {
            $arx1 = $x2 - $arx1;    $ary1 = $y2 + $ary1;
            $arx2 = $x2 - $arx2;    $ary2 = $y2 + $ary2;
        }
    }
    if ($ang > -90 && $ang < 0) {
        if (($x2 > $x1) && ($y2 > $y1)) {
            $arx1 = $x2 - $arx1;    $ary1 = $y2 + $ary1;
            $arx2 = $x2 - $arx2;    $ary2 = $y2 + $ary2;
        } elseif (($x2 < $x1) && ($y2 < $y1)) {
            $arx1 = $x2 + $arx1;    $ary1 = $y2 - $ary1;
            $arx2 = $x2 + $arx2;    $ary2 = $y2 - $ary2;
        }
    }

    if ($debug) {
        echo ("Angle of line is (".$ang*180/pi().")</br>");
        echo ("Angle of line1 is $arrangdeg1</br>");
        echo ("Angle of line2 is $arrangdeg2</br>");
        echo ("$arx1,$ary1&nbsp;&nbsp;&nbsp;$x2,$y2</br>");
        echo ("$arx2,$ary2&nbsp;&nbsp;&nbsp;$x2,$y2");
        exit;
    }
    
    $array_arrows = array (
                    'x1' =>$arx1,
                    'y1' => $ary1,
                    'x2' => $arx2,
                    'y2' => $ary2
                    );
    return $array_arrows;

}

$x1 = 200; $y1 = 200;
$x2 = 400; $y2 = 100;
$arrhead = 15; //10px
$arrang = 10; //10 deg

$ar_arrws = get_arrowheads ($x1, $y1, $x2, $y2, $arrhead, $arrang);

$im  = imagecreate (400, 400); 
$w   = imagecolorallocate ($im, 255, 255, 255); 
$red = imagecolorallocate ($im, 255, 0, 0); 

//creates the base line
imageline ($im, $x1, $y1, $x2, $y2, $green);
imageline ($im, $x1+1, $x2+1, $y1+1, $y2+1, $red);
imageline ($im, $x2, $y2, $ar_arrws['x1'], $ar_arrws['y1'], $green);
imageline ($im, $x2, $y2, $ar_arrws['x2'], $ar_arrws['y2'], $green);

?>

down

Tyron ¶

19 years ago

// Here's a function for drawing a rotated gradient Rectangle (based on a previous note)

// Create An Image 255x255
$img = ImageCreateTrueColor(255, 255);

GradientRect($img,50,50,80,80,30);

ImagePng($img,"test.png");
ImageDestroy($img);
echo "<br><img src=\"test.png\">";

function GradientRect($img, $x1, $y1, $x2, $y2, $wdt) {
  $alpha = atan2($y2-$y1,$x2-$x1);
  $real_wdt = $wdt*sin($alpha);
  $real_hgt = $wdt*cos($alpha);
  echo "real wdt:".$real_wdt;
  echo "<br>real hgt:".$real_hgt;
  echo "<br>angle: ".($angle*180/pi());
  $plotD = 0;
  $i=0; 

  $dy = $real_hgt/$wdt;
  $dx = $real_wdt/$wdt;
  $drgb= 256/$wdt;
  while($i++ < $wdt) {
    // Draw a line and move it down and make it lighter to get the gradient effect
    ImageLine($img, $x1-$i*$dx, $y1+$i*$dy, $x2-$i*$dx, $y2+$i*$dy, ImageColorAllocate($img, $i*$drgb, 0, 0));
    ImageLine($img, $x1-$i*$dx+1, $y1+$i*$dy, $x2-$i*$dx+1, $y2+$i*$dy, ImageColorAllocate($img, $i*$drgb, 0, 0));

  }
}

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yl at sota dot ch ¶

20 years ago

Simple function to create border for jpg-images:

function createImageBorder($imgName){

     $img     =  substr($imgName, 0, -4); // remove fileExtension
     $ext     = ".jpg";
     $quality = 95;
     $borderColor = 255;  // 255 = white
     
    /*
     a                         b
     +-------------------------+
     |                          
     |          IMAGE           
     |                          
     +-------------------------+
     c                         d   
    */
    
    $scr_img = imagecreatefromjpeg($img.$ext);
    $width   = imagesx($scr_img);
    $height  = imagesy($scr_img);
              
        // line a - b
        $abX  = 0;
        $abY  = 0;
        $abX1 = $width;
        $abY1 = 0;
        
        // line a - c
        $acX  = 0;
        $acY  = 0;
        $acX1 = 0;
        $acY1 = $height;
        
        // line b - d
        $bdX  = $width-1;
        $bdY  = 0;
        $bdX1 = $width-1;
        $bdY1 = $height;
        
        // line c - d
        $cdX  = 0;
        $cdY  = $height-1;
        $cdX1 = $width;
        $cdY1 = $height-1;
            
       // DRAW LINES    
        imageline($scr_img,$abX,$abY,$abX1,$abY1,$borderColor);
        imageline($scr_img,$acX,$acY,$acX1,$acY1,$borderColor);
        imageline($scr_img,$bdX,$bdY,$bdX1,$bdY1,$borderColor);
        imageline($scr_img,$cdX,$cdY,$cdX1,$cdY1,$borderColor);
        
      // create copy from image    
        imagejpeg($scr_img, $img."_border.jpg", $quality);
        imagedestroy($scr_img); 
  }
    
    createImageBorder("myfile.jpg");

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v dot krypton at yandex dot ru ¶

8 years ago

This function draw border to image.
function imageborder($img,$color) {
    $width = imagesx($img);
    $height = imagesy($img);
    ImageLine($img, 0, 0, $width, 0, $color);
    ImageLine($img, 0, 0, 0, $height, $color);
    ImageLine($img, $width-1, 0, $height-1, $height, $color);
    ImageLine($img, 0, $height-1, $width, $height-1, $color);
}

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teixeira dot cmo at gmail.com ¶

7 years ago

If you draw on a canvas, using js ctx.lineJoin = "round"; and then try to do the same on a GD $img the result will not be the same. 
Here is a simple code to draw a line similar to one made using lineJoin round.

$w=5; //set your line thickness;
imagesetthickness($img, $w);
imageline($img, $x1, $y1, $x2, $y2, $color);
imagesetthickness($img, 1);
imagefilledellipse ( $img , $x2 , $y2 , $w ,$w, $color);

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Anonymous ¶

13 years ago

The most bold-line-functions i found have problems with lines in a certian direction (they draw smaller lines with some angles). To do a real bold line just use this function:



<?php

function imageBoldLine($resource, $x1, $y1, $x2, $y2, $Color, $BoldNess=2, $func='imageLine') 

{

 $center = round($BoldNess/2);

 for($i=0;$i<$BoldNess;$i++)

 {  

  $a = $center-$i; if($a<0){$a -= $a;}

  for($j=0;$j<$BoldNess;$j++)

  {

   $b = $center-$j; if($b<0){$b -= $b;}

   $c = sqrt($a*$a + $b*$b);

   if($c<=$BoldNess)

   {

    $func($resource, $x1 +$i, $y1+$j, $x2 +$i, $y2+$j, $Color);

   }

  }

 }         

}

?>

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Anonymous ¶

15 years ago

Here's another way of modifying likavcan's code to display filled arrows. This makes use of imagefilledpolygon(...) instead of recursive function calls.

<?php
function arrow($im, $x1, $y1, $x2, $y2, $alength, $awidth, $color) {
    $distance = sqrt(pow($x1 - $x2, 2) + pow($y1 - $y2, 2));

    $dx = $x2 + ($x1 - $x2) * $alength / $distance;
    $dy = $y2 + ($y1 - $y2) * $alength / $distance;

    $k = $awidth / $alength;

    $x2o = $x2 - $dx;
    $y2o = $dy - $y2;

    $x3 = $y2o * $k + $dx;
    $y3 = $x2o * $k + $dy;

    $x4 = $dx - $y2o * $k;
    $y4 = $dy - $x2o * $k;

    imageline($im, $x1, $y1, $dx, $dy, $color);
    imagefilledpolygon($im, array($x2, $y2, $x3, $y3, $x4, $y4), 3, $color);
}
?>

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huirong dot jin at gmail dot com ¶

16 years ago

An example to draw Amplitude Modulation curve: y = c * sin (x/a) * sin (x/b) . You can easily modify the codes to create your own oscilloscope application!

<?php
header ("Content-type: image/png");
$myImage = @imagecreatetruecolor(640, 480)
      or die("Cannot Initialize new GD image stream");
$text_color = imagecolorallocate($myImage, 255, 255, 224);
$poly_color = imagecolorallocate($myImage, 124, 120, 224);

//calculate x-value and y-value point by point
$points = array();
for ($i=1; $i<640; $i=$i+1)
{
    //define curve's function
    $x = $i; //define x-value, which is $i itself 
    $y = 150*sin($x/80)*sin($x/5);//define y-value
    
    //append a point's x-value and y-value
    $points[] = $x; //x-value
    $points[] = 240-$y;  //y-value
}

//count points
$totalPoints = count($points)/2;

//drawing title
$title = "Final Plot ($totalPoints points)";
imagestring($myImage, 3, 5, 5,  $title, $text_color);

/** drawing points one by one, notice if there 
 * are 10 points, we need to draw 9 lines: 
 * 1) point 0 to 1; 
 * 2) point 1 to 2;
 * ...
 * ...
 * 9) point 8 to 9; 
 */
for ($i=0; $i<$totalPoints-1; $i++)
{
    imageLine($myImage, $points[2*$i], $points[1+2*$i], $points[2+2*$i], $points[3+2*$i], $poly_color);    
}

//finalizing
imagepng($myImage);
imagedestroy($myImage);
?>

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admin at xpmail dot net ¶

17 years ago

example of a Simple grid...
bool imagegrid ( resource $image, int $width, int $Height, int $size, mixed $color )

<?php
Header("Content-type: image/png");
$Width=450;
$Height=450;

$img = ImageCreateTrueColor($Width, $Height);

$bg = imagecolorallocate($img, 255, 255, 255);
imagefill($img, 0, 0, $bg);

$grid = imagecolorallocate($img, 225, 245, 249);

imagesetstyle($img, array($bg, $grid));
imagegrid($img, $Width, $Height, 10, IMG_COLOR_STYLED);
//makegrid($img, $Width, $Height, 10, $grid);

ImagePNG($img);
ImageDestroy($img);

function imagegrid($image, $w, $h, $s, $color)
{
    for($iw=1; $iw<$w/$s; $iw++){imageline($image, $iw*$s, 0, $iw*$s, $w, $color);}
    for($ih=1; $ih<$h/$s; $ih++){imageline($image, 0, $ih*$s, $w, $ih*$s, $color);}
}
?>

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meid at gmx dot at ¶

19 years ago

Some simple code to draw lines with specific thickness using "imagefilledpolygon". Useful if your gdlib does not support "imagesetthickness". 

<?
function dickelinie($img,$start_x,$start_y,$end_x,$end_y,$color,$thickness) 
{
    $angle=(atan2(($start_y - $end_y),($end_x - $start_x))); 

    $dist_x=$thickness*(sin($angle));
    $dist_y=$thickness*(cos($angle));
    
    $p1x=ceil(($start_x + $dist_x));
    $p1y=ceil(($start_y + $dist_y));
    $p2x=ceil(($end_x + $dist_x));
    $p2y=ceil(($end_y + $dist_y));
    $p3x=ceil(($end_x - $dist_x));
    $p3y=ceil(($end_y - $dist_y));
    $p4x=ceil(($start_x - $dist_x));
    $p4y=ceil(($start_y - $dist_y));
    
    $array=array(0=>$p1x,$p1y,$p2x,$p2y,$p3x,$p3y,$p4x,$p4y);
    imagefilledpolygon ( $img, $array, (count($array)/2), $color );
}
// Example:
header ("Content-type: image/jpeg");
$img = ImageCreate (210, 210) or die("Cannot Initialize new GD image stream ");
$backgroundcolor = ImageColorAllocate ($img, 255, 255, 255);
$orange = ImageColorAllocate($img, 252, 102, 4);
dickelinie($img, 10, 10, 10, 200,$orange,2);
dickelinie($img, 10, 200, 200, 10,$orange,2);    
dickelinie($img, 200, 10, 200, 200,$orange,2);
imagejpeg($img);   
ImageDestroy($img);

?>

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Atelier ”慶”

WEBクリエイター歴２０年、最先端技術と安心をお届けします。

PHPのお勉強！

imageline

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User Contributed Notes 28 notes