Function beltc draw surface by belts. You can use ‘x’ style for drawing lines in other direction.
MGL code:
call 'prepare2d' title 'BeltC plot':rotate 50 60:box:beltc a b
C++ code:
void smgl_beltc(mglGraph *gr) { mglData a,b; mgls_prepare2d(&a,&b); if(big!=3) gr->Title("BeltC plot"); gr->Rotate(50,60); gr->Box(); gr->BeltC(a,b); }