I am getting an “error C1008: undefined variable “inverse”” error in GLSL 1.5 with the line
mat4 iMVP = inverse(InvMVP);
determinant() works fine with a mat4 in the same shader source. Any ideas what the problem could be? I’m using an NVIDIA 9600 with the latest(?) 196.21, drivers for window 7 64-bit.