imagefilledpolygon

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

    imagefilledpolygon — Draw a filled polygon

    Descrizione

    Signature as of PHP 8.0.0 (not supported with named arguments)

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

    Alternative signature (deprecated as of PHP 8.1.0)

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

    imagefilledpolygon() creates a filled polygon in the given image.

    Elenco dei parametri

    image

    Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().

    points

    An array containing the x and y coordinates of the polygons vertices consecutively.

    num_points

    Total number of points (vertices), which must be at least 3.

    If this parameter is omitted as per the second signature, points must have an even number of elements, and num_points is assumed to be count($points)/2.
    color

    A color identifier created with imagecolorallocate().

    Valori restituiti

    Restituisce true in caso di successo, false in caso di fallimento.

    Log delle modifiche

    Versione Descrizione
    8.1.0 The parameter num_points has been deprecated.
    8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

    Esempi

    Example #1 imagefilledpolygon() example

    <?php
    // set up array of points for polygon
    $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)
    );

    // create image
    $image = imagecreatetruecolor(250, 250);

    // allocate colors
    $bg = imagecolorallocate($image, 0, 0, 0);
    $blue = imagecolorallocate($image, 0, 0, 255);

    // fill the background
    imagefilledrectangle($image, 0, 0, 249, 249, $bg);

    // draw a polygon
    imagefilledpolygon($image, $values, $blue);

    // flush image
    header('Content-type: image/png');
    imagepng($image);
    ?>

    Il precedente esempio visualizzerà qualcosa simile a:

    Output of example : imagefilledpolygon()

    Vedere anche:

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    User Contributed Notes 9 notes

    up
    3
    tatlar at yahoo dot com
    19 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
    1
    jylyn at hotmail dot com
    19 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
    martin at eksperimentrum dot dk
    7 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
    8 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
    10 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
    16 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
    etnekor at tar dot hu
    19 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
    18 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);
    }
    ?>
    up
    -1
    webmaster at mywebsolution dot de
    18 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);
    ?>
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