imageellipse

(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)

imageellipse — Draw an ellipse

Descrizione

imageellipse(
    GdImage $image,
    int $center_x,
    int $center_y,
    int $width,
    int $height,
    int $color
): bool

Draws an ellipse centered at the specified coordinates.

Elenco dei parametri

image: Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().
center_x: x-coordinate of the center.
center_y: y-coordinate of the center.
width: The ellipse width.
height: The ellipse height.
color: The color of the ellipse. A color identifier created with imagecolorallocate().

Valori restituiti

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

Log delle modifiche

Versione	Descrizione
8.0.0	`image` expects a GdImage instance now; previously, a valid `gd` resource was expected.

Esempi

Example #1 imageellipse() example

<?php

// Create a blank image.
$image = imagecreatetruecolor(400, 300);

// Select the background color.
$bg = imagecolorallocate($image, 0, 0, 0);

// Fill the background with the color selected above.
imagefill($image, 0, 0, $bg);

// Choose a color for the ellipse.
$col_ellipse = imagecolorallocate($image, 255, 255, 255);

// Draw the ellipse.
imageellipse($image, 200, 150, 300, 200, $col_ellipse);

// Output the image.
header("Content-type: image/png");
imagepng($image);

?>

Il precedente esempio visualizzerà qualcosa simile a:

Note

Nota:
imageellipse() ignores imagesetthickness().

Vedere anche:

imagefilledellipse() - Draw a filled ellipse
imagearc() - Draws an arc

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User Contributed Notes 3 notes

down

simon_nuttall at hotmail dot com ¶

18 years ago

This is an optimised and bug fixed version of nojer at yahoo dot com's rotatedellipse function. I've changed it so that the arguments are compatible with imageellipse. See notes on imagearc for original version.

<?php

function rotatedellipse($im, $cx, $cy, $width, $height, $rotateangle, $colour, $filled=false) {
  // modified here from nojer's version
  // Rotates from the three o-clock position clockwise with increasing angle.
  // Arguments are compatible with imageellipse.

  $width=$width/2;
  $height=$height/2;

  // This affects how coarse the ellipse is drawn.
  $step=3;

  $cosangle=cos(deg2rad($rotateangle));
  $sinangle=sin(deg2rad($rotateangle));

  // $px and $py are initialised to values corresponding to $angle=0.
  $px=$width * $cosangle;
  $py=$width * $sinangle;
  
  for ($angle=$step; $angle<=(180+$step); $angle+=$step) {
    
    $ox = $width * cos(deg2rad($angle));
    $oy = $height * sin(deg2rad($angle));
    
    $x = ($ox * $cosangle) - ($oy * $sinangle);
    $y = ($ox * $sinangle) + ($oy * $cosangle);
 
    if ($filled) {
      triangle($im, $cx, $cy, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
      triangle($im, $cx, $cy, $cx-$px, $cy-$py, $cx-$x, $cy-$y, $colour);
    } else {
      imageline($im, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
      imageline($im, $cx-$px, $cy-$py, $cx-$x, $cy-$y, $colour);
    }
    $px=$x;
    $py=$y;
  }
}

function triangle($im, $x1,$y1, $x2,$y2, $x3,$y3, $colour) {
   $coords = array($x1,$y1, $x2,$y2, $x3,$y3);
   imagefilledpolygon($im, $coords, 3, $colour);
}

?>

down

julian ¶

19 years ago

if you want to display an ellipse in the upper left corner of an image, you can easily calculate the corresponding cx and cy values. this example will draw an ellipse having the same width and height as the image.

<?php

$ellipse_width = 100;
$ellipse_height = 200;

$ellipse_cx = ($ellipse_width / 2);
$ellipse_cy = ($ellipse_height / 2);

$img_x = $ellipse_width;
$img_y = $ellipse_height;

$img = imagecreate($img_x, $img_y);
$bg = imagecolorallocate($img, 255,255,255);

$ellipse_color = imagecolorallocate($img, 0, 0, 0);

imageellipse($img, $ellipse_cx, $ellipse_cy, $ellipse_width, $ellipse_height, $ellipse_color);

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

?>

down

agentyoungsoo at hanmail dot net ¶

21 years ago

When you wana use "ImageEllipse" function 
in under GD 2.0.2 version, you can use "ImageArc" like bellow

----------------------------------------------------
$file_name = "test.png";

$screen_x = 300;
$screen_y = 200;

$x1 = $screen_x / 2;
$y1 = $screen_y / 2;

$radius = 30;

$image = ImageCreate($screen_x, $screen_y);
$black = ImageColorAllocate($image, 0,0,0);

ImageArc($image, $x1, $y1, $radius , $radius , 0, 360, $black);

ImagePng($image, $file_name); 
ImageDestroy($image); 
----------------------------------------------------

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