PHP 8.1.15 Released!

imageellipse

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

imageellipse画椭圆

说明

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

绘制以指定坐标为中心的椭圆。

参数

image

由图象创建函数(例如imagecreatetruecolor())返回的 GdImage 对象。

center_x

中间的 x 坐标。

center_y

中间的 y 坐标。

width

椭圆的宽度。

height

椭圆的高度。

color

椭圆的颜色。颜色标识符使用 imagecolorallocate() 创建。

返回值

成功时返回 true, 或者在失败时返回 false

更新日志

版本 说明
8.0.0 image expects a GdImage instance now; previously, a resource was expected.

范例

示例 #1 imageellipse() 示例

<?php

// 新建一个空白图像
$image = imagecreatetruecolor(400, 300);

// 填充背景色
$bg = imagecolorallocate($image, 0, 0, 0);

// 选择椭圆的颜色
$col_ellipse = imagecolorallocate($image, 255, 255, 255);

// 画一个椭圆
imageellipse($image, 200, 150, 300, 200, $col_ellipse);

// 输出图像
header("Content-type: image/png");
imagepng($image);


?>

以上例程的输出类似于:

示例输出:imageellipse()

注释

注意:

imageellipse() 忽略 imagesetthickness()

参见

add a note

User Contributed Notes 3 notes

up
-1
simon_nuttall at hotmail dot com
16 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
-1
julian
18 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
-2
agentyoungsoo at hanmail dot net
20 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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