One can easily create stereo image in MathGL. Stereo image can be produced by making two subplots with slightly different rotation angles. The corresponding code looks like this:
int sample(mglGraph *gr) { mglData a; mgls_prepare2d(&a); gr->Light(true); gr->SubPlot(2,1,0); gr->Rotate(50,60+1); gr->Box(); gr->Surf(a); gr->SubPlot(2,1,1); gr->Rotate(50,60-1); gr->Box(); gr->Surf(a); return 0; }