Function surfa is similar to surf but its transparency is determined by another data.
MGL code:
call 'prepare2d' title 'SurfA plot':rotate 50 60:light on:alpha on:box:surfa a b
C++ code:
void smgl_surfa(mglGraph *gr) { mglData a,b; mgls_prepare2d(&a,&b); if(big!=3) gr->Title("SurfA plot"); gr->Rotate(50,60); gr->Alpha(true); gr->Light(true); gr->Box(); gr->SurfA(a,b); }