Function contf draw filled contours. You can select automatic (default) or manual levels for contours.
MGL code:
call 'prepare2d' list v -0.5 -0.15 0 0.15 0.5 new a1 30 40 3 '0.6*sin(2*pi*x+pi*(z+1)/2)*sin(3*pi*y+pi*z) + 0.4*cos(3*pi*(x*y)+pi*(z+1)^2/2)' subplot 2 2 0:title 'ContF plot (default)':rotate 50 60:box:contf a subplot 2 2 1:title 'manual levels':rotate 50 60:box:contf v a subplot 2 2 2:title '"\_" style':rotate 50 60:box:contf a '_' subplot 2 2 3:title 'several slices':rotate 50 60:box:contf a1
C++ code:
void smgl_contf3(mglGraph *gr) { mglData c; mgls_prepare3d(&c); if(big!=3) gr->Title("ContF3 sample"); gr->Rotate(50,60); gr->Light(true); gr->Box(); gr->ContF3(c,"x"); gr->ContF3(c); gr->ContF3(c,"z"); gr->Cont3(c,"kx"); gr->Cont3(c,"k"); gr->Cont3(c,"kz"); }