k3d/share/shaders/k3d_windowlight.sl:44:  float offset, modulus, yfract, xfract;
k3d/share/shaders/k3d_windowlight.sl:64:	yfract =
k3d/share/shaders/k3d_windowlight.sl:69:      yfract = 0;
k3d/share/shaders/k3d_windowlight.sl:81:    Cl = intensity * mix(darkcolor, lightcolor, yfract * xfract);
