GLSL 1.5 mat4 inverse

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.

I wouldn’t be surprised, if that function were not (yet) implemented. It is rather unlikely that anyone would want to execute it in production code, since matrix inversions are computationally extremely intensive. Better calculate it once and upload it as a uniform.


Thanks for the answer, I thought I might be doing something wrong with my source. I was only using it as a test, so i guess it is no big loss.