半字体令人敬畏的心脏评级css

I'm generating a rating system using font-awesome fa-heart class. It is working fine by colouring the full heart, but I'm in trouble when trying to fill it in red only the first half of the heart. I have been searching but always are stars and not a half-heart, always full heart and not from font-awesome.I'm generating a rating system using font-aweso