imageellipse

(PHP 4 >= 4.0.6, PHP 5)

imageellipseDraw 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(400300);

// Select the background color.
$bg imagecolorallocate($image000);

// Fill the background with the color selected above.
imagefill($image00$bg);

// Choose a color for the ellipse.
$col_ellipse imagecolorallocate($image255255255);

// Draw the ellipse.
imageellipse($image200150300200$col_ellipse);

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

?>

Il precedente esempio visualizzerĂ  qualcosa simile a:

Output of example : imageellipse()

Note

Nota:

This function requires GD 2.0.2 or later.

Vedere anche:

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User Contributed Notes 4 notes

up
0
themountainlion at gmail dot com
6 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.
up
0
simon_nuttall at hotmail dot com
8 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);
}

?>
up
0
julian
9 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);

?>
up
-1
agentyoungsoo at hanmail dot net
12 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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