超越PHP - Exceed PHP: imagearc

imagearc

(PHP 3, PHP 4 , PHP 5)

imagearc -- 画椭圆弧

说明

int imagearc ( resource image, int cx, int cy, int w, int h, int s, int e, int color)

imagearc() 以 cx，cy（图像左上角为 0, 0）为中心在 image 所代表的图像中画一个椭圆弧。w 和 h 分别指定了椭圆的宽度和高度，起始和结束点以 s 和 e 参数以角度指定。0°位于三点钟位置，以逆时针方向绘画。

例子 1. 用 imagearc() 画一个圆


<?php



// create a 200*200 image

$img = imagecreate(200, 200);



// allocate some colors

$white = imagecolorallocate($img, 255, 255, 255);



// draw a white circle

imagearc($img, 100, 100, 150, 150, 0, 360, $white);



// output image in the browser

header("Content-type: image/png");

imagepng($img);



// free memory

imagedestroy($img);



?>

参见 imageellipse()，imagefilledellipse() 和 imagefilledarc()。

add a note User Contributed Notes
imagearc

travis at duluth dot com
23-Dec-1999 10:36

The wierd thing is that the first two integers tell where to place the
"circle".

So for example I first create the
"pallet" to place the circle on.

$image = imagecreate(500,
500);  

(this makes a huge 500x500 gif :) )

$colorBody =
imagecolorallocate($image, 0, 0, 0);

(make the default color of the
"pallet" black

$circleColor = imagecolorallocate($image, 255,
0, 255);

(going to make the circle an ugly pink
color)

imagearc($image, 250, 250, 300, 300, 0, 360,
$circleColor);

Places the image in the center (250,250) and the circle
is 300 pixels in diameter.



Hope this helps.

 

Travis Kent
Beste

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