ImagickDraw::circle()
(PECL imagick 2.0.0)
Draws a circle
说明
ImagickDraw::circle(float $ox,float $oy,float $px,float $py): bool
Warning本函数还未编写文档,仅有参数列表。
Draws a circle on the image.
参数
- $ox
origin x coordinate
- $oy
origin y coordinate
- $px
perimeter x coordinate
- $py
perimeter y coordinate
返回值
没有返回值。
范例
Example #1 ImagickDraw::circle()
<?php function circle($strokeColor, $fillColor, $backgroundColor, $originX, $originY, $endX, $endY) { //Create a ImagickDraw object to draw into. $draw = new \ImagickDraw(); $strokeColor = new \ImagickPixel($strokeColor); $fillColor = new \ImagickPixel($fillColor); $draw->setStrokeOpacity(1); $draw->setStrokeColor($strokeColor); $draw->setFillColor($fillColor); $draw->setStrokeWidth(2); $draw->setFontSize(72); $draw->circle($originX, $originY, $endX, $endY); $imagick = new \Imagick(); $imagick->newImage(500, 500, $backgroundColor); $imagick->setImageFormat("png"); $imagick->drawImage($draw); header("Content-Type: image/png"); echo $imagick->getImageBlob(); } ?>
The four values required here are a bit confusing. After all, a circle is defined by three values: the x, y coordinates of the centre, and the radius, r. The fourth value is redundant, but has to be given, otherwise the function fails. One way of coping with this redundancy is: <?php $draw = new ImagickDraw (); //given that $x and $y are the coordinates of the centre, and $r the radius: $draw->circle ($x, $y, $x + $r, $y); ?> There are any number of actions which are synonymous with the last, including: <?php $draw->circle ($x, $y, $x, $y + $r); $draw->circle ($x, $y, $x - $r, $y); $draw->circle ($x, $y, $x, $y - $r); // etc, etc. ?> Hope this helps.
This example creates a circle, one part green, one part red using kind of masks for transparency, which you might know from Photoshop. drawImage() is a quick helper for debug output (see code comments) to help you reproduce the process. <?php function drawImage(Imagick $im) { $im->setCompressionQuality(100); $im->setImageFormat("jpg"); header("Content-Type: image/" . $im->getImageFormat()); echo $im; exit; } // define red/green layer $layer1 = new Imagick(); $layer1->newImage(100, 100, "none"); $red = new ImagickDraw(); $red->setFillColor("#FF0000"); $red->rectangle(0, 0, 50, 100); $green = new ImagickDraw(); $green->setFillColor("#00FF00"); $green->rectangle(50, 0, 100, 100); $layer1->drawImage($red); $layer1->drawImage($green); # debug output: two rectangles # drawImage($layer1); // define circle mask $layer2 = new Imagick(); $layer2->newImage(100, 100, "none"); $circle = new ImagickDraw(); $circle->setFillColor("#FFFFFF"); $circle->circle(50, 50, 48, 98); $layer2->drawImage($circle); # debug output: the mask # drawImage($layer2); // use mask $layer1->compositeImage($layer2, Imagick::COMPOSITE_DSTIN, 0, 0); # debug output: the result of our mask usage # drawImage($layer1); // define background $layer3 = new Imagick(); $layer3->newImage(100, 100, "none"); $layer3->compositeImage($layer1, Imagick::COMPOSITE_DEFAULT, 0, 0); // define ring as background $layer4 = new Imagick(); $layer4->newImage(100, 100, "white"); // this is our background $ring1 = new ImagickDraw(); $ring1->setFillColor("black"); $ring1->circle(50, 50, 50, 99); $layer4->drawImage($ring1); # debug output: this is a black circle (not our mask, which is similar, but a little bit smaller) # drawImage($layer4); // use black circle as background (this creates our circle border) $layer4->compositeImage($layer3, Imagick::COMPOSITE_DEFAULT, 0, 0); # debug output: here we go with our circle border # drawImage($layer4); // draw separator between red and green rectangle (now semi circles) $line = new ImagickDraw(); $line->setStrokeWidth(1); $line->setStrokeColor("black"); $line->line(50, 1, 50, 99); // add our separator line $layer4->drawImage($line); drawImage($layer4); ?> To understand how the COMPOSITE_* constants effect the image merging process, see here: http://www.imagemagick.org/Usage/compose/#duff-porter