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imagefilledpolygon

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

imagefilledpolygonDesenha um polígono preenchido

Descrição

Assinatura a partir do PHP 8.0.0 (sem suporte a argumentos com nome)

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

Assinatura alternativa (descontinuada a partir do PHP 8.1.0)

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

imagefilledpolygon() cria um polígono preenchido na imagem fornecida em image.

Parâmetros

image

Um objeto GdImage, retornado por uma das funções de criação de imagem, como imagecreatetruecolor().

points

Um array contendo as coordenadas x e y dos vértices consecutivos do polígono.

num_points

Número total de pontos (vértices), que devem ser pelo menos 3.

Se este parâmetro for omitido na segunda assinatura, points deve ter um número par de elementos, e num_points será assumido como count($points)/2.
color

Um identificador de cor criado com imagecolorallocate().

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Registro de Alterações

Versão Descrição
8.1.0 O parâmetro num_points foi descontinuado.
8.0.0 O parâmetro image agora espera uma instância de GdImage; anteriormente, um resource gd válido era esperado.

Exemplos

Exemplo #1 Exemplo de imagefilledpolygon()

<?php
// configura o array de pontos para o polígono
$values = array(
40, 50, // Ponto 1 (x, y)
20, 240, // Ponto 2 (x, y)
60, 60, // Ponto 3 (x, y)
240, 20, // Ponto 4 (x, y)
50, 40, // Ponto 5 (x, y)
10, 10 // Ponto 6 (x, y)
);

// cria imagem
$image = imagecreatetruecolor(250, 250);

// aloca cores
$bg = imagecolorallocate($image, 0, 0, 0);
$blue = imagecolorallocate($image, 0, 0, 255);

// preenche o fundo
imagefilledrectangle($image, 0, 0, 249, 249, $bg);

// desenha um polígono
imagefilledpolygon($image, $values, 6, $blue);

// descarrega a imagem
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
?>

O exemplo acima produzirá algo semelhante a:

Saída do exemplo: imagefilledpolygon()

Veja Também

add a note

User Contributed Notes 9 notes

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
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
-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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