brendt / responsive-images

        $sizes = [];

        if ($this->includeSource && (!$this->maxWidth || $width <= $this->maxWidth) && (!$this->maxFileSize || $fileSize <= $this->maxFileSize)) {

            $sizes[$width] = $height;

        }

        do {

            $fileSize = $fileSize * $this->stepModifier;

            $fileSize = $fileSize * $this->stepModifier;

            $newWidth = floor(sqrt(($fileSize / $pixelPrice) / $ratio));

            if ((!$this->maxFileSize || $fileSize <= $this->maxFileSize) && (!$this->maxWidth || $newWidth <= $this->maxWidth)) {

                $sizes[(int) $newWidth] = (int) $newWidth * $ratio;

            }

        } while ($fileSize > $this->minFileSize && $newWidth > $this->minWidth);

        return $sizes;