Submit a Pull Request Report a Bug

imagefilledpolygon

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

imagefilledpolygon — 绘制多边形并填充

说明

自 PHP 8.0.0 起的签名（不支持命名参数）

imagefilledpolygon(GdImage $image, array $points, int $color): bool

替代签名（从 PHP 8.1.0 起弃用）

imagefilledpolygon(
    GdImage $image,
    array $points,
    int $num_points,
    int $color
): bool

imagefilledpolygon() 在指定 image 中创建多边形并填充。

参数

image: 由图象创建函数(例如imagecreatetruecolor())返回的 GdImage 对象。
points: 包含连续多边形顶点的 x 和 y 坐标的数组。
num_points: 点（顶点）的总数，必须最少为 3。
如果根据第二个签名省略此参数，则 points 必须具有偶数个元素，并且假定 num_points 为 count($points)/2。
color: 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
8.1.0	弃用参数 `num_points`。
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 imagefilledpolygon() 示例

<?php
// 为多边形设置点数组
$values = array(
            40,  50,  // Point 1 (x, y)
            20,  240, // Point 2 (x, y)
            60,  60,  // Point 3 (x, y)
            240, 20,  // Point 4 (x, y)
            50,  40,  // Point 5 (x, y)
            10,  10   // Point 6 (x, y)
            );

// 创建图像
$image = imagecreatetruecolor(250, 250);

// 分配颜色
$bg   = imagecolorallocate($image, 0, 0, 0);
$blue = imagecolorallocate($image, 0, 0, 255);

// 填充背景
imagefilledrectangle($image, 0, 0, 249, 249, $bg);

// 绘制多边形
imagefilledpolygon($image, $values, 6, $blue);

// 输出图像
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
?>

以上示例的输出类似于：

参见

imagepolygon() - 绘制多边形

＋add a note

User Contributed Notes 9 notes

down

tatlar at yahoo dot com ¶

17 years ago

<?php function _makeFiveSidedStar( $x, $y, $radius, $shape='polygon', $spiky=NULL ) {
    // $x, $y co-ords of origin (in pixels), $radius (in pixels), $shape - 'polygon' or 'star', $spikiness - ratio between 0 and 1
    $point = array() ;                                                                                                                    
    $angle = 360 / 5 ;                                                                                                                    
    $point[0]['x'] = $x ;                                                                                                                 
    $point[0]['y'] = $y - $radius ;                                                                                                       
    $point[2]['x'] = $x + ( $radius * cos( deg2rad( 90 - $angle ) ) ) ; 
    $point[2]['y'] = $y - ( $radius * sin( deg2rad( 90 - $angle ) ) ) ;
    $point[4]['x'] = $x + ( $radius * sin( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
    $point[4]['y'] = $y + ( $radius * cos( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
    $point[6]['x'] = $x - ( $radius * sin( deg2rad( 180 - ( $angle*2 ) ) ) ) ;                                                            
    $point[6]['y'] = $y + ( $radius * cos( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
    $point[8]['x'] = $x - ( $radius * cos( deg2rad( 90 - $angle ) ) ) ;                                                                   
    $point[8]['y'] = $y - ( $radius * sin( deg2rad( 90 - $angle ) ) ) ;
    if( $shape == 'star' ) {
        if( $spiky == NULL ) $spiky = 0.5 ;  // default to 0.5
        $indent = $radius * $spiky ;
        $point[1]['x'] = $x + ( $indent * cos( deg2rad( 90 - $angle/2 ) ) ) ;                                                             
        $point[1]['y'] = $y - ( $indent * sin( deg2rad( 90 - $angle/2 ) ) ) ;                                                     
        $point[3]['x'] = $x + ( $indent * sin( deg2rad( 180 - $angle ) ) ) ;                                                              
        $point[3]['y'] = $y - ( $indent * cos( deg2rad( 180 - $angle ) ) ) ;
        $point[5]['x'] = $x ;                                                                                                             
        $point[5]['y'] = $y + ( $indent * sin( deg2rad( 180 - $angle ) ) ) ;
        $point[7]['x'] = $x - ( $indent * sin( deg2rad( 180 - $angle ) ) ) ;                                                              
        $point[7]['y'] = $y - ( $indent * cos( deg2rad( 180 - $angle ) ) ) ;                                                              
        $point[9]['x'] = $x - ( $indent * cos( deg2rad( 90 - $angle/2 ) ) ) ;                                                             
        $point[9]['y'] = $y - ( $indent * sin( deg2rad( 90 - $angle/2 ) ) ) ;
    }
    ksort( $point ) ;
    $coords = array() ;  // new array                                                                                                                 
    foreach( $point as $pKey=>$pVal ) {                                                                                                   
        if( is_array( $pVal ) ) {                                                                                                         
            foreach( $pVal as $pSubKey=>$pSubVal ) {                                                                                      
                if( !empty( $pSubVal ) ) array_push( $coords, $pSubVal ) ;                                                                
            }                                                                                                                             
        }                                                                                                                                 
    }
    return $coords ;
}
$values = _makeFiveSidedStar( 100, 100, 50, 'star' ) ;
// Put values into imagepolygon function. You need to define the $image and $color, and flush it out to an image type.?>

down

jylyn at hotmail dot com ¶

17 years ago

In spite of what it says about requiring more than 3 vertices, it is possible to draw a triangle with this function!

down

martin at eksperimentrum dot dk ¶

5 years ago

How to draw a simple 6-sided star img where x,y is center of the star and s is the size:

function drawStar($img, $x, $y, $s, $color) {
    $x=$x-$s/2;
    $y=$y-$s/4;
    $points=array($x,$y, $x+$s/2,$y+$s, $x+$s,$y);
    imagefilledpolygon($img, $points, 3, $color);
    $points=array($x,2/3*$s+$y, $x+$s/2,$y-$s/3, $x+$s,2/3*$s+$y);
    imagefilledpolygon($img, $points, 3, $color);
}

down

Steween ¶

6 years ago

My version of drawStar (with examples)

<?php
header ("Content-type: image/png");

/* drawStar or regular polygon
    $x, $y  -> Position in the image
    $radius -> Radius of the star
    $spikes -> Number of spikes (min 2)
    $ratio  -> Ratio between outer and inner points
    $dir    -> Rotation 270° for having an up spike( with ratio<1)
*/
function drawStar($x, $y, $radius, $spikes=5, $ratio=0.5, $dir=270) {
    $coordinates = array();
    $angle = 360 / $spikes ;
    for($i=0; $i<$spikes; $i++){
        $coordinates[] = $x + (       $radius * cos(deg2rad($dir+$angle*$i)));
        $coordinates[] = $y + (       $radius * sin(deg2rad($dir+$angle*$i)));
        $coordinates[] = $x + ($ratio*$radius * cos(deg2rad($dir+$angle*$i + $angle/2)));
        $coordinates[] = $y + ($ratio*$radius * sin(deg2rad($dir+$angle*$i + $angle/2)));
    }
    return $coordinates ;
}

// 14*20+24*2 = 328 Examples
$im = imagecreate(800,600);
     imagecolorallocate($im,   0,   0,   0);
$w = imagecolorallocate($im, 255, 255, 255);
$r = imagecolorallocate($im, 255,   0,   0);
for ($spikes=2; $spikes<16; $spikes++) { //[2-15] 
    for ($ratio=1; $ratio<21; $ratio++) { //[0.1-2.0]
        $values = drawStar(40*$ratio-20, $spikes*40-60, 10, $spikes, $ratio/10);
        imagefilledpolygon($im, $values, count($values)/2, ($ratio % 5 == 0) ? $r : $w);
    }
}
for ($dir=0; $dir<24; $dir++) {
    $values = drawStar(30*$dir+20, 580, 10, 2, 1.5, $dir*15);
    imagefilledpolygon($im, $values, count($values)/2, $w);
    $values = drawStar(30*$dir+20, 580, 10, 2, 0.2, $dir*15);
    imagefilledpolygon($im, $values, count($values)/2, $r);
}
imagepng($im);
imagedestroy($im);
?>

down

rbenheidorn at gmail dot com ¶

8 years ago

Discovered while working on printing geographical boundaries to an image: if you provide floating point vertices, then the decimal value is automatically truncated. This can cause images drawn with floating point vertices to shift slightly towards the top-left corner. My personal resolution is to round all of the vertices to their nearest whole values, which eliminates this shift.

down

austinoblouk at yahoo dot com ¶

14 years ago

Actually the minimum it allows is 3. It says "Total number of vertices, which must be bigger than 3." but it allows 3...

down

etnekor at tar dot hu ¶

17 years ago

There is a simple function to draw a filled point with a chosen radius and color.

<?php
function drawPoint($img, $radius, $origo_x, $origo_y, $pointColor)
{
  for ($i=0;$i<=360;$i++)
  {
    $pont[] = $origo_x + ($radius * sin(deg2rad($i)));
    $pont[] = $origo_y - ($radius * cos(deg2rad($i)));
  }
  reset($pont);
  ImageFilledPolygon ($img, $pont, (sizeof($pont)/2), $pointColor);
}
?>

down

-1

webmaster at mywebsolution dot de ¶

16 years ago

Just thought that 'tatlar at yahoo dot com's function has some redundant code in it, so I tried to "improve" it. Now you can choose a variable number of spikes.

<?php
error_reporting(E_ALL);
function drawStar($x, $y, $radius, $spikes=5) {
    // $x, $y -> Position in the image
    // $radius -> Radius of the star
    // $spikes -> Number of spikes

    $coordinates = array();
    $angel = 360 / $spikes ;

    // Get the coordinates of the outer shape of the star
    $outer_shape = array();
    for($i=0; $i<$spikes; $i++){
        $outer_shape[$i]['x'] = $x + ($radius * cos(deg2rad(270 - $angel*$i)));
        $outer_shape[$i]['y'] = $y + ($radius * sin(deg2rad(270 - $angel*$i)));
    }

    // Get the coordinates of the inner shape of the star
    $inner_shape = array();
    for($i=0; $i<$spikes; $i++){
        $inner_shape[$i]['x'] = $x + (0.5*$radius * cos(deg2rad(270-180 - $angel*$i)));
        $inner_shape[$i]['y'] = $y + (0.5*$radius * sin(deg2rad(270-180 - $angel*$i)));
    }

    // Bring the coordinates in the right order
    foreach($inner_shape as $key => $value){
        if($key == (floor($spikes/2)+1))
             break;
        $inner_shape[] = $value;
        unset($inner_shape[$key]);
    }

    // Reset the keys
    $i=0;
    foreach($inner_shape as $value){
        $inner_shape[$i] = $value;
        $i++;
    }

    // "Merge" outer and inner shape
    foreach($outer_shape as $key => $value){
         $coordinates[] = $outer_shape[$key]['x'];
         $coordinates[] = $outer_shape[$key]['y'];
         $coordinates[] = $inner_shape[$key]['x'];
         $coordinates[] = $inner_shape[$key]['y'];
    }

    // Return the coordinates
    return $coordinates ;
}

// Example
$spikes = 5;

$values = drawStar(250, 250, 200, $spikes);
$im = imagecreate(500,500);
imagecolorallocate($im,0,0,0);
$w = imagecolorallocate($im, 255, 255, 255);
imagefilledpolygon($im, $values, $spikes*2, $w);
imageGIF($im);
imagedestroy($im);
?>

down

-2

Arnapou ¶

16 years ago

I discovered that the GD imagefilledpolygon function is incorrect for some drawing with transparent color (for example red 50% : RGBA = 255, 0, 0, 64).

I tried to draw a complex form with lots of points really near (1 pixel of distance) and a transparent red.

The problem was : some border pixels were not drawn by the imagefilledpolygon but were drawn with imagepolygon !?!?

So I wrote my own imagefilledpolygon function which work very well in all case I tested.

<?php
// $points should be an array of coordinates like that :
$points = array(
    array(0, 0),
    array(100, 50),
    array(90, 100),
    array(50, 50),
    array(70, 30),
    array(10, 10),
);
?>

<?php
function myimagefilledpolygon(& $img, $points, $color) {
    $scanline = 99999;
    // compute edges
    $all_edges = array();
    $n = count($points);
    for($i=0; $i<$n; $i++) {
        $p1 = $points[$i];
        if ($i == $n-1) { $p2 = $points[0]; } else { $p2 = $points[$i+1]; }
        $x1 = $p1[0]; $y1 = $p1[1];
        $x2 = $p2[0]; $y2 = $p2[1];
        if ($y1 != $y2) {
            $invslope = ($x2 - $x1)/($y2 - $y1);
            if ($y1 < $y2 ) {
                $ymin = $y1;
                $xval = $x1;
                $ymax = $y2;
            } else {
                $ymin = $y2;
                $xval = $x2;
                $ymax = $y1;
            }
            $all_edges[] = array($ymin, $ymax, $xval, $invslope);
            if ($ymin < $scanline) { $scanline = $ymin; }
        } else {
            if ($y1 < $scanline) { $scanline = $y1; }
            if ($y2 < $scanline) { $scanline = $y2; }
        }
    }
    // draw
    $active = array();
    do {
        // add edges to active array
        $tmp = array();
        $n = count($all_edges);
        for($i=0; $i<$n; $i++) {
            if ($all_edges[$i][0] == $scanline) {
                $active[] = $all_edges[$i];
            } else {
                $tmp[] = $all_edges[$i];
            }
        }
        $all_edges = $tmp;
        // remove previous edges from active array
        $tmp = array();
        $n = count($active);
        for($i=0; $i<$n; $i++) {
            if ($active[$i][1] > $scanline) {
                $tmp[] = $active[$i];
            }
        }
        $active = $tmp;
        // sort active tab
        $n = count($active);
        for($i=0; $i<$n-1; $i++) {
            $min = $i;
            for($k=$i+1; $k<$n; $k++) {
                if ($active[$k][2] < $active[$min][2]) { $min = $k; }
            }
            if ($i != $min) {
                $tmp = $active[$i];
                $active[$i] = $active[$min];
                $active[$min] = $tmp;
            }
        }
        // draw
        $n = count($active);
        for($i=0; $i<$n; $i+=2) {
            if ($i+1 < $n) {
                if ($tmp[$i][2] == $active[$i+1][2]) {
                    imagesetpixel($img, round($active[$i][2]), $scanline, $color);
                } else {
                    imageline($img, round($active[$i][2]), $scanline, round($active[$i+1][2]), $scanline, $color);
                }
            }
        }
        // increment x values
        $n = count($active);
        for($i=0; $i<$n; $i++) { $active[$i][2] += $active[$i][3]; }
        $scanline++;
    } while (count($all_edges) + count($active) > 0);
}
?>

＋add a note