Re: Probable df_no_use_specs bug

[Daniel J S. <dan...@ie...>]

Daniel J Sebald wrote:

> In attempting to make both plot3d.c use only df_readline(), even for 
> matrix data, I think I've uncovered a bug, or perhaps more than one.


<snip>

> If someone else wants to tackle that one, fine.  I'm just going to fix 
> it in the "image/binary" stuff so that it works for a single 
> "df_readline()". 


On second thought, I'll leave it unfixed in the patch.  There are too 
many instances of df_no_use_specs being used in strange ways.  Here's a 
problem note:

            /* FIXME EAM - as it stands we cannot have LABELPOINTS   */
            /* with pm3d colors, because they don't agree on columns */

and right near that is

            if (df_no_use_specs==4) {
            /* getting color from an explicitly given 4th column */
            pm3d_color_from_column = TRUE;
            x = v[0];
            y = v[1];
            z = v[2];
            color = v[3];
            break;
            }

I think what has happened here is because matrix data is currently read 
by df_3dmatrix(), which doesn't return the number of columns, there is a 
tendency inside plot3d.c to use "df_no_use_spec" as the number of 
columns of available data.  That works under the condition the data came 
from df_3dmatrix.  But if it didn't, like in the example I've shown 
previous, problems arise.

My feeling on this is that if df_readline() is only used to bring in 
data, the "df_no_use_specs" can be removed from "datafile.h".  That will 
force things to be reorganized ever so slightly in plot3d.c so that 
strange behavior doesn't creep in.

Dan