imageellipse

(PHP 4 >= 4.0.6, PHP 5)

imageellipse — Draw an ellipse

Descrizione

bool imageellipse ( resource $image , int $cx , int $cy , int $width , int $height , int $color )

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().
cx: x-coordinate of the center.
cy: 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.

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:
This function requires GD 2.0.2 or later.

Vedere anche:

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

imagefill

imagedestroy

[edit] Last updated: Tue, 21 May 2013

add a note User Contributed Notes imageellipse - [4 notes]

down

themountainlion at gmail dot com ¶

4 years ago


In example #1 above, the variable $bg is set but not used. Set the background to anything but black ,and it won't take effect. The example needs 



imagefill($image, 0, 0, $bg);



Some other image function examples have the same issue.

down

simon_nuttall at hotmail dot com ¶

6 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 ¶

8 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 ¶

10 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); 

----------------------------------------------------

add a note