Cropping logic results in black image - php

Question

Struggling to get the math correct for image cropping, hoping someone else is able to see my issue. It appears to be overshooting the dimensions of the image leaving 1 pixel of the original image on the left of the result.
function thumbnail_create($file, $w, $h, $crop = false, $output_filename = null, $output_dirname = null)
{
list($width, $height) = getimagesize(FILESPATH . $file);
$r = $width / $height;
if ($crop) {
if ($width > $height) {
$width = ceil($width - ($width * abs($r - $w / $h)));
} else {
$height = ceil($height - ($height * abs($r - $w / $h)));
}
$newwidth = $w;
$newheight = $h;
} else {
if ($w / $h > $r) {
$newwidth = $h * $r;
$newheight = $h;
} else {
$newheight = $w / $r;
$newwidth = $w;
}
}
$mime = mime_content_type(FILESPATH . $file);
$handler = "imagepng";
if (in_array($mime, ["image/gif"])) {
$src = imagecreatefromgif(FILESPATH . $file);
$handler = "imagegif";
} elseif (in_array($mime, ["image/jpeg", "image/pjpeg", "image/jpeg", "image/pjpeg"])) {
$src = imagecreatefromjpeg(FILESPATH . $file);
$handler = "imagejpeg";
} elseif (in_array($mime, ["image/png"])) {
$src = imagecreatefrompng(FILESPATH . $file);
}
if (!isset($src) || !$src) {
return false;
}
$newImage = imagecreatetruecolor($newwidth, $newheight);
imagealphablending($newImage, false);
imagesavealpha($newImage, true);
imagecopyresampled($newImage, $src, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
if (!empty($output_dirname)) {
make_dir($output_dirname);
}
// BUILD OUTPUT PATH/FILE
$ext = pathinfo($file, PATHINFO_EXTENSION);
if (empty($output_filename)) {
$output_filename = str_replace("." . $ext, '-thumb.' . $ext, basename($file));
}
if (empty($output_dirname)) {
$output_dirname = dirname($file);
}
$output = $output_dirname . '/' . $output_filename;
$handler($newImage, FILESPATH . $output);
return $output;
}
thumbnail_create('news/feature/fluffy-kitty.png, 100, 100, true)
Before:
After:
Original width: int(862)
Original height: int(192)
Cropped width: float(-2146)
Cropped height: int(192)