PHP 5.6.0beta1 released

imageellipse

(PHP 4 >= 4.0.6, PHP 5)

imageellipse画一个椭圆

说明

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

在指定的坐标上画一个椭圆。

参数

image

由图象创建函数(例如imagecreatetruecolor())返回的图象资源。

cx

中间的 X 坐标。

cy

中间的 Y 坐标。

width

椭圆的宽度。

height

椭圆的高度。

color

椭圆的颜色。颜色标识符由 imagecolorallocate() 创建。

返回值

成功时返回 TRUE, 或者在失败时返回 FALSE

范例

Example #1 imageellipse() 例子

<?php

// 新建一个空白图像
$image imagecreatetruecolor(400300);

// 填充背景色
$bg imagecolorallocate($image000);

// 选择椭圆的颜色
$col_ellipse imagecolorallocate($image255255255);

// 画一个椭圆
imageellipse($image200150300200$col_ellipse);

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


?>

以上例程的输出类似于:

例子输出: imageellipse()

注释

Note:

本函数需要 GD 2.0.2 或更高版本。

参见

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User Contributed Notes 4 notes

up
0
themountainlion at gmail dot com
5 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.
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0
simon_nuttall at hotmail dot com
7 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);
}

?>
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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);

?>
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0
agentyoungsoo at hanmail dot net
11 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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