PHP 图片处理为圆形

话不多说上代码

function radius_img($imgpath, $radius = 0){
    $index = strpos($imgpath,"?");
    if($index !== false){
        $imgpath = substr($imgpath,0,$index);
    }
    $ext = pathinfo($imgpath);
    $src_img = null;
    switch ($ext['extension']){
        case 'jpg':
        case 'jpeg':
            $src_img = imagecreatefromjpeg($imgpath);
            break;
        case 'png':
            $src_img = imagecreatefrompng($imgpath);
            break;
        case 'gif':
            $src_img = imagecreatefromgif($imgpath);
            break;
    }
    $wh = getimagesize($imgpath);
    $w = $wh[0];
    $h = $wh[1];
    $radius = $radius == 0 ? (min($w, $h) / 2) : $radius;
    $img = imagecreatetruecolor($w, $h);
    //这一句一定要有
    imagesavealpha($img, true);
    //拾取一个完全透明的颜色,最后一个参数127为全透明
    $bg = imagecolorallocatealpha($img, 255, 255, 255, 0);
    imagefill($img, 0, 0, $bg);
    $r = $radius; //圆 角半径
    for ($x = 0; $x < $w; $x++){
        for ($y = 0; $y < $h; $y++){
            $rgbColor = imagecolorat($src_img, $x, $y);
            if (($x >= $radius && $x <= ($w - $radius)) || ($y >= $radius && $y <= ($h - $radius))){
                //不在四角的范围内,直接画
                imagesetpixel($img, $x, $y, $rgbColor);
            }else{
                //在四角的范围内选择画
                //上左
                $y_x = $r; //圆心X坐标
                $y_y = $r; //圆心Y坐标
                if (((($x - $y_x) * ($x - $y_x) + ($y - $y_y) * ($y - $y_y)) <= ($r * $r))){
                    imagesetpixel($img, $x, $y, $rgbColor);
                }
                //上右
                $y_x = $w - $r; //圆心X坐标
                $y_y = $r; //圆心Y坐标
                if (((($x - $y_x) * ($x - $y_x) + ($y - $y_y) * ($y - $y_y)) <= ($r * $r))){
                    imagesetpixel($img, $x, $y, $rgbColor);
                }
                //下左
                $y_x = $r; //圆心X坐标
                $y_y = $h - $r; //圆心Y坐标
                if (((($x - $y_x) * ($x - $y_x) + ($y - $y_y) * ($y - $y_y)) <= ($r * $r))){
                    imagesetpixel($img, $x, $y, $rgbColor);
                }
                //下右
                $y_x = $w - $r; //圆心X坐标
                $y_y = $h - $r; //圆心Y坐标
                if (((($x - $y_x) * ($x - $y_x) + ($y - $y_y) * ($y - $y_y)) <= ($r * $r))){
                    imagesetpixel($img, $x, $y, $rgbColor);
                }
            }
        }
    }
    return $img;
}