void Framebuffer::attachDepthBuffer(const Renderbuffer& rb)
 {
     bind();
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rb.getHandle());
     _depth = true;
 }
 void Framebuffer::attachColorBuffer(const Renderbuffer& rb)
 {
     bind();
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rb.getHandle());
     _color = true;
 }