CascadiaPHP 2024

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 xy 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_pointscount($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:

示例输出:imagefilledpolygon()

参见

add a note

User Contributed Notes 9 notes

up
0
martin at eksperimentrum dot dk
6 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);
}
up
0
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);
?>
up
0
rbenheidorn at gmail dot com
9 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.
up
0
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...
up
0
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);
?>
up
0
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!
up
0
etnekor at tar dot hu
18 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);
}
?>
up
-1
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.?>
up
-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);
}
?>
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