ImagickDraw::arc()

(PECL imagick 2.0.0)

Draws an arc

说明

ImagickDraw::arc(float $sx,float $sy,float $ex,float $ey,float $sd,float $ed): bool

Warning

本函数还未编写文档，仅有参数列表。

Draws an arc falling within a specified bounding rectangle on the image.

参数

$sx

Starting x ordinate of bounding rectangle

$sy

starting y ordinate of bounding rectangle

$ex

ending x ordinate of bounding rectangle

$ey

ending y ordinate of bounding rectangle

$sd

starting degrees of rotation

$ed

ending degrees of rotation

返回值

没有返回值。

范例

Example #1 ImagickDraw::arc()

<?php
function arc($strokeColor, $fillColor, $backgroundColor, $startX, $startY, $endX, $endY, $startAngle, $endAngle) {
    //Create a ImagickDraw object to draw into.
    $draw = new \ImagickDraw();
    $draw->setStrokeWidth(1);
    $draw->setStrokeColor($strokeColor);
    $draw->setFillColor($fillColor);
    $draw->setStrokeWidth(2);
    $draw->arc($startX, $startY, $endX, $endY, $startAngle, $endAngle);
    //Create an image object which the draw commands can be rendered into
    $image = new \Imagick();
    $image->newImage(IMAGE_WIDTH, IMAGE_HEIGHT, $backgroundColor);
    $image->setImageFormat("png");
    //Render the draw commands in the ImagickDraw object 
    //into the image.
    $image->drawImage($draw);
    //Send the image to the browser
    header("Content-Type: image/png");
    echo $image->getImageBlob();
}
?>

You can do a pie chart with a combination of arc and polygon functions (there really ought to be a built-in command for this)
<?php
// create a new canvas object and a white image
$canvas   = new Imagick();
$canvas->newImage(600, 600, 'grey');
image_pie($canvas, 300, 300, 200, 0, 45, 'red');
image_pie($canvas, 300, 300, 200, 45, 125, 'green');
image_pie($canvas, 300, 300, 200, 125, 225, 'blue');
image_pie($canvas, 300, 300, 200, 225, 300, 'cyan');
image_pie($canvas, 300, 300, 200, 300, 360, 'orange');
// output the image
$canvas->setImageFormat('png');
header("Content-Type: image/png");
echo $canvas;
exit;
// FUNCTIONS
function image_arc( &$canvas, $sx, $sy, $ex, $ey, $sd, $ed, $color = 'black' ) {
  // draw arc on canvas
  // $sx, $sy, $ex, $ey specify a bounding rectangle of a circle with the origin in the middle
  // $sd, and $ed specify start and end angles in degrees
  $draw = new ImagickDraw();
  $draw->setFillColor($color);
  $draw->setStrokeColor($color);
  $draw->setStrokeWidth(1);
  $draw->arc($sx, $sy, $ex, $ey, $sd, $ed);
  $canvas->drawImage($draw);
}
function image_pie( &$canvas, $ox, $oy, $radius, $sd, $ed, $color = 'black' ) {
  // draw pie segment
  // $ox, $oy specify the circle origin
  // $sd, and $ed specify start and end angles in degrees
  // degrees start from 0 = East, and go clockwise
  // position 1 - convert degrees to radians and get first point on perimeter of circle
  $x1   = $radius * cos($sd / 180 * 3.1416);
  $y1   = $radius * sin($sd / 180 * 3.1416);
  // position 2 - convert degrees to radians and get second point on perimeter of circle
  $x2   = $radius * cos($ed / 180 * 3.1416);
  $y2   = $radius * sin($ed / 180 * 3.1416);
  // draw segment triangle - specify the 3 points and draw a polygon
  $points = array(array('x' => $ox, 'y' => $oy), array('x' => $ox + $x1, 'y' => $oy + $y1), array('x' => $ox + $x2, 'y' => $oy + $y2));
  image_polygon($canvas, $points, $color);
  // draw corrsesponding arc to complete the "pie" segment
  image_arc($canvas, $ox - $radius, $oy - $radius, $ox + $radius, $oy + $radius, $sd, $ed, $color);
}
function image_polygon( &$canvas, $points, $color = 'black' ) {
  // draw a polygon on canvas
  $draw = new ImagickDraw();
  $draw->setFillColor($color);
  $draw->setStrokeColor($color);
  $draw->setStrokeWidth(1);
  $draw->polygon($points);
  $canvas->drawImage($draw);
}
?>